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REACH

Butan-1-ol

EC number: 200-751-6 | CAS number: 71-36-3

Life Cycle description
Uses advised against

Toxicological information

Endpoint summary

Administrative data

Key value for chemical safety assessment

Effects on fertility

Description of key information

Oral

Explorative study on female fertility and prenatal development, rat: The NOAEL maternal toxicity including fertility: 5000 mg/kg bw/d (Sitarek 1994, RL 2).

Repeated dose toxicity, rat, 90 d: NOEL reproductive organs = 500 mg/kg bw (US EPA 1986; RL 1)

Inhalation

Behavioural peri-, postnatal developmental (neuro)toxicity study, rat, NOAEC parental including fertility = 6000 ppm (18.5 mg/L, Nelson 1989a, RL 2)

n-Butyl acetate inhalation

Two-generation reproduction toxicity study, rat, vapour, whole body, NAOEC fertility = 2000 ppm (9.7 mg/L), NOAEC developmental toxicity and systemic toxicity= 750 ppm (3.6 mg/L). The developmental effects were associated with clear maternal toxicity they are not considered as an independent effect (Nemec, 2010, RL 1).

Link to relevant study records

Referenceopen all close all

Reference 1

Endpoint:: two-generation reproductive toxicity
Type of information:: experimental study
Adequacy of study:: weight of evidence
Study period:: From 24 OCT 2005 to 25 JUN 2010
Reliability:: 1 (reliable without restriction)
Rationale for reliability incl. deficiencies:: guideline study
Qualifier:: according to guideline
Guideline:: OECD Guideline 416 (Two-Generation Reproduction Toxicity Study)
Deviations:: no
Qualifier:: according to guideline
Guideline:: EPA OPPTS 870.3800 (Reproduction and Fertility Effects)
Deviations:: no
GLP compliance:: yes
Limit test:: no
Species:: rat
Strain:: Sprague-Dawley
Sex:: male/female
Details on test animals or test system and environmental conditions:: TEST ANIMALS (Crl:CD (SD))
- Source: Charles River Laboratories, Inc. Raleigh, North Carolina, USA
- Age at study initiation: (P) 7 wks
- Weight at study initiation: (P) Males: 207 g to 263 g ( group means: 235-237 g); Females: 151 to 201 g (group means: 169-171 g)
- Fasting period before study: no
- Housing: 3 per cage (by sex) for the initial acclimation period; individually thereafter except for mating period and after parturition; following weaning dams were individually housed until scheduled necropsy; weaned pups were housed by litter in plastic cages for 1 week, beginning on PND 28, the F1 and F2 pups were inidvidually housed until the start of the mating period (F1) or until euthanasia (F2)
- Diet: PMI Nutrition International, LLC, Certified Rodent LabDiet 5002; ad libitum except during exposure periods
- Water: reverse osmosis-purified drinking water; ad libitum except during exposure periods
- Acclimation period: 13 days

ENVIRONMENTAL CONDITIONS
- Temperature (°C): 22 +/- 3
- Humidity (%): 50 +/- 20
- Air changes (per hr): at least 10
- Photoperiod (hrs dark / hrs light): 12/12
Route of administration:: inhalation: vapour
Type of inhalation exposure (if applicable):: whole body
Vehicle:: unchanged (no vehicle)
Details on exposure:: GENERATION OF TEST ATMOSPHERE / CHAMBER DESCRIPTION
- Exposure apparatus: 2 cubic metre stainless steel and glass whole body exposure chambers/group
- Method of holding animals in test chamber: individually housed in stainless steel wire-mesh caging suspended over cageboard during exposure
- Source and rate of air: provided from a HEPA- and charcoal-filtered, temperature and humidity controlled source
- Method of conditioning air: test article vapour was directed to the exposure chamber inlet where the vapour concentration was reduced to the desired level by mixing with the chamber ventilation air
- System of generating vapour: glass-bead column-type vaporization system
- Temperature, humidity, pressure in air chamber: daily mean chamber temperature: 21 to 22°C; daily mean chamber humidity: 43 to 56%; slight negative pressure
- Air flow rate: mean values: 430 to 475 litters per minute
- Air change rate: at least 12 to 15 per hour
- Treatment of exhaust air: charcoal and HEPA filtration

TEST ATMOSPHERE
- Brief description of analytical method used: gas chromatograph (GC)
- Samples taken from breathing zone: yes; approximately every 35 minute
Details on mating procedure:: - M/F ratio per cage: 1:1
- Length of cohabitation: up to 14 days
- Proof of pregnancy: vaginal plug or sperm in vaginal smear referred to as day 0 of pregnancy
- After 14 days of unsuccessful pairing replacement of first male by another male with proven fertility for an additional 7 days.
- Further matings after two unsuccessful attempts: no
- After successful mating each pregnant female was caged: plastic maternity cage with nesting material
Analytical verification of doses or concentrations:: yes
Details on analytical verification of doses or concentrations:: - gas chromatography
Duration of treatment / exposure:: - 6 hours per day for at least 70 consecutive days prior to mating
- F0 and F1 females continued to be exposed throughout mating and gestation through gestation day 20; inhalation exposure was suspended from gestation day 21 through lactation day 4
- on lactation days 1 to 4 F0 and F1 maternal animals were exposed via oral gavage
- inhalation exposure of F0 and F1 females was re-initiated on lactation day 5 and continued through the day prior to euthanasia
- inhalation exposure of the F1 was initiated on PND 22
Frequency of treatment:: 7 days per week
Details on study schedule:: - F1 parental animals not mated until 2-3 weeks after selected from the F1 litters.
- Selection of parents from F1 and F2 generation when pups were 21 days of age.
- Age at mating of the mated animals in the study: prior to the F0 pairing (study week 10) the animals were approximately 17 weeks old; prior to the F1 pairing (study week 29) the animals were approximately 15-16 weeks old
Dose / conc.:: 0 ppm (nominal)
Remarks:: inhalation exposure
Dose / conc.:: 750 ppm (nominal)
Remarks:: inhalation exposure
Dose / conc.:: 1 500 ppm (nominal)
Remarks:: inhalation exposure
Dose / conc.:: 2 000 ppm (nominal)
Remarks:: inhalation exposure
Dose / conc.:: 0 mg/kg bw/day (actual dose received)
Remarks:: F0 and F1 maternal animals during lactation day 1-4; administered as 3 equal doses, approximately 2 hours apart
Dose / conc.:: 1 125 mg/kg bw/day (actual dose received)
Remarks:: F0 and F1 maternal animals during lactation day 1-4; administered as 3 equal doses, approximately 2 hours apart
Dose / conc.:: 2 250 mg/kg bw/day (actual dose received)
Remarks:: F0 and F1 maternal animals during lactation day 1-4; administered as 3 equal doses, approximately 2 hours apart
Dose / conc.:: 3 000 mg/kg bw/day (actual dose received)
Remarks:: F0 and F1 maternal animals during lactation day 1-4; administered as 3 equal doses, approximately 2 hours apart
No. of animals per sex per dose:: 30/sex/group
Control animals:: yes, concurrent vehicle
Details on study design:: - Dose selection rationale: based on range finding study (see section 7.8.1)
Positive control:: none
Parental animals: Observations and examinations:: CAGE SIDE OBSERVATIONS: Yes
- Time schedule: twice daily
- Cage side observations were included.

DETAILED CLINICAL OBSERVATIONS: Yes
- Time schedule: weekly

BODY WEIGHT: Yes
- Time schedule for examinations:
F0 and F1 males: weekly
F0 and F1 females: weekly until evidence of copulation; on gestation day 0, 4, 7, 11, 14, 20 and on lactation day 1, 4, 5 (pre-exposure), 7, 14, 21; weekly after weaning until scheduled necropsy
F2 males and females: weekly beginning on PND 28 through euthanasia

FOOD CONSUMPTION AND COMPOUND INTAKE:
- Time schedule for examinations:
F0 and F1 males: weekly (not recorded during mating period)
F0 and F1 females: weekly until evidence of copulation (not recorded during mating period); on gestation day 0, 4, 7, 11, 14, 20 and on lactation day 1, 4, 5 (pre-exposure), 7, 14, 21; weekly after weaning until scheduled necropsy
F2 males and females: weekly beginning on PND 28 through euthanasia
- Food consumption for each animal determined and mean daily diet consumption calculated as g food/kg body weight/day: Yes
- Compound intake calculated as time-weighted averages from the consumption and body weight gain data: Yes
Oestrous cyclicity (parental animals):: Vaginal lavages were performed daily and the slides were evaluated to assess the regularity and duration of the estrous cycles of each F0 and F1 female for 21 days prior to pairing and continuing until evidence of mating was observed or until the end of the mating period. The average cycle length was calculated for complete estrous cycles (i.e., the total number of returns to metestrus [M] or diestrus [D] from estrus [E] or proestrus [P], beginning 21 days prior to initiation of the mating period and continuing until the detection of evidence of mating). Estrous cycle length was determined by counting the number of days from the first M or D in a cycle to the first M or D in a subsequent cycle. The cycle during which evidence of mating was observed for a given animal was not included in the mean individual estrous cycle length calculation. Vaginal lavages were also performed on the day of necropsy to determine the stage of estrus.
Sperm parameters (parental animals):: Parameters examined in P and F1 male parental generations:
testis weight, epididymis weight, cauda epididymis weight, sperm count in testes, calculation of sperm production rate, sperm count in epididymides, sperm motility, progressive motility and sperm morphology
Litter observations:: STANDARDISATION OF LITTERS
- Performed on day 4 postpartum: yes
- If yes, maximum of 10 pups/litter (5/sex/litter as nearly as possible); excess pups were killed and discarded.

PARAMETERS EXAMINED
The following parameters were examined in F1 and F2 offspring: number and sex of pups, stillbirths, live births, postnatal mortality, presence of gross anomalies, body weights, physical or behavioural abnormalities

GROSS EXAMINATION OF DEAD PUPS: yes, for external and internal abnormalities
Postmortem examinations (parental animals):: SACRIFICE
- Male animals: All surviving F0 and F1 animals were euthanized following completion of the parturition period.
- Maternal animals: All surviving F0 and F1 animals that delivered were euthanized between 6 and 10 days after wening of their litters. F0 and F1 females that mated but did not give birth were euthanized on presumed gestation day 25. F0 and F1 females that experienced total litter loss were euthanized within 24 hours. F0 and F1 females that failed to mate within the first 14 days of the breeding period were euthanized on gestation day 15 (females that mated with the second male) or post-cohabitation day 15 (females that did not mate with the second male).
Animals underwent complete necropsy and selective histopathologic examination.

GROSS NECROPSY (F0, F1 and F2 adults)
- Gross necropsy consisted of examination of the external surface, all orifices, the cranial cavity, the external surfaces of the brain and spinal cord, and the thoracic, abdominal and pelvic cavities, including viscera. For females that delivered or had macroscopic evidence of implantation, the numbers of former implantation sites (the attachment site of the placenta to the uterus) were recorded. The number of unaccounted-for sites was calculated for each female by subtracting the number of pups born from the number of former implantation sites observed. Numbers of corpora lutea were also recorded for females euthanized on gestation day 15. For females that failed to deliver, a pregnancy status was determined,
and specific emphasis was placed on anatomic or pathologic findings that may have interfered with pregnancy.

HISTOPATHOLOGY (F0 and F1 parental animals)
Microscopic evaluations were performed on the following tissues for all F0 and F1 parental animals from the control and high-exposure groups:

Adrenals Prostate
Coagulating glands Seminal vesicles
Kidneys Spleen
Liver Testis and epididymis (right)
Lungs Thyroid
Nasal passages (additionally investigated in animals of the 750 ppm group) Uterus
Ovaries Vagina
Oviducts Gross lesions
Pituitary

In addition, microscopic evaluations were performed on the following tissues for F0 and F1 parental animals from the low- and mid-exposure groups that did not mate or produce offspring.

Males Females

Epididymis a Ovaries
Prostate Oviducts
Seminal vesicles Uterus
Testis a Pituitary
Pituitary

a = Right testis and epididymis only.

ORGAN WEIGHTS (F0 and F1 adults)
Adrenals Prostate
Brain Seminal vesicles (with coagulating glands and accessory fluids)

Epididymisa (total and cauda)
Kidneys Spleen
Liver Testes
Lungs (prior to inflation with fixative) Thyroid
Ovaries Uterus (with oviducts and cervix)
Pituitary
Postmortem examinations (offspring):: SACRIFICE
All surviving F1 and F2 pups not selected for test article exposure were euthanized on PND 21 by carbon dioxide inhalation. F1 and F2 weanlings exposed to the test article beginning on PND 22 but were not selected to continue exposure into the respective maturation phases were euthanized by carbon dioxide inhalation followed by exsanguination between PND 36-47 (F1 generation) and on PND 36 (F2 generation).
Animals underwent necropsy and/or organ weight determination.

- These animals were subjected to postmortem examinations (macroscopic and/or microscopic examination) as follows:

GROSS NECROPSY (F1 and F2 pups/weanlings)
Gross necropsies with emphasis on developmental morphology and organs of the reproductive system were performed on nonselected F1 and F2 pups euthanized on PND 21, on the F1 weanlings from dam no. 99179 in the 1500 ppm group that were euthanized on PND 28, and on the extra weanlings selected for inhalation exposure beginning on PND 22 that were euthanized between PND 36-47 (F1 generation) and PND 36 (F2 generation).
The following F1 and F2 organs were collected from 3 pups/sex/litter that survived to their
scheduled termination on PND 21. Only gross lesions were collected and preserved for
the F1 and F2 weanlings exposed up to PND 47 or PND 36.

All organs were placed in 10% neutral-buffered formalin (except as noted):

Adrenal glands (2) Seminal vesicles (2)
Brain Spleen
Coagulating glands (2) Testes and epididymides a (2)
Kidneys (2) Thymus
Liver Uterus with cervix
Ovaries (2) Vagina
Pituitary Gross lesions
Prostate

a = If retained, testis and epididymis were fixed in Bouin’ s solution.

HISTOPATHOLOGY
not performed

ORGAN WEIGTHS (F2 adults and F1 and F2 pups)
Brain Thymus
Pituitary Testes
Spleen Uterus
Statistics:: Analyses were conducted using two-tailed tests (except as noted otherwise) for a minimum significance level of 5%, comparing each test article-exposed group to the control group by sex. Where applicable, the litter was used as the experimental unit.
Parental mating, copulation, conception and fertility indices were analyzed using the Chi-square test with Yates’ correction factor (Hollander and Wolfe, 1999). Mean parental body weights (premating, gestation and lactation) and body weight gains, mean parental food consumption and food efficiency (at each interval), implantation sites, number of unaccounted-for sites, pre-coital intervals, estrous cyclicity, follicular counts (ovary), gestation length, mean day of attainment of pre-weaning and post-weaning developmental landmarks, mean weight on the day of attainment of post-weaning developmental landmarks, mean pup body weights (postnatal period), mean number of pups born, live litter size, organ weights (absolute, relative to body and relative to brain) were subjected to a parametric one-way analysis of variance (ANOVA) to determine intergroup differences (Snedecor and Cochran, 1980). If the ANOVA revealed statistically significant (p<0.05) intergroup variance, Dunnett's test (Dunnett, 1964) was used to compare the test article-treated groups to the control group.
Mean litter proportions (percent per litter) of postnatal pup viability, pup sex ratio at birth, percentage of motile and progressively motile sperm and percentages of sperm with normal morphology were subjected to the Kruskal-Wallis nonparametric ANOVA test (Kruskal and Wallis, 1952) to determine intergroup differences. If the ANOVA revealed statistically significant (p<0.05) intergroup variance, Dunn’s test (Dunn, 1964) was used to compare the test article-treated groups to the control group. Epididymal and testicular sperm numbers and sperm production rates were analyzed by a t-test (Steel and Torrie, 1980).
Reproductive indices:: Male (Female) Mating Index (%) = No. of Males (Females) with Evidence of Mating (or Females Confirmed Pregnant) / Total No. of Males (Females) Used for Mating x 100

Male Fertility Index (%) = No. of Males Siring a Litter / Total No. of Males Used for Mating x 100

Male Copulation Indes (%) = No. of Males Siring a Litter / No. of Males with Evidence of Mating (or Females Confirmed Pregnant) x 100

Female Fertility Index (%) = No. of Females with Confirmed Pregnancy / Total No. of Females Used for Mating x 100

Female Conception Index (%) = No. of Females with Confirmed Pregnancy / No. of Females with Evidence of Mating (or Females Confirmed Pregnant) x 100
Offspring viability indices:: Mean Live Litter Size = Total Viable Pups on PND 0 / No. Litters with Viable Pups on PND 0

Postnatal Survival Between Birth and PND 0 or PND 4 (Pre-Selection) (% Per Litter) = Summ (Viable Pups Per Litter on PND 0 or PND 4/No. of Pups Born Per Litter)/ No. of Litters Per Group x 100

Postnatal Survival for All Other Intervals (% Per Litter) = Summ (Viable Pups Per Litter at End of Interval N/Viable Pups per Litter at Start of Interval N) / No. of Litters Per Group x 100

N = PND 0-1, 1-4 (Pre Selection, 4 (Post Selection)-7, 7-14, 14-21 or 4 (Post Selection)-21
Clinical signs:: no effects observed
Body weight and weight changes:: effects observed, treatment-related
Food consumption and compound intake (if feeding study):: effects observed, treatment-related
Organ weight findings including organ / body weight ratios:: effects observed, treatment-related
Histopathological findings: non-neoplastic:: effects observed, treatment-related
Other effects:: not examined
Reproductive function: oestrous cycle:: no effects observed
Reproductive function: sperm measures:: no effects observed
Reproductive performance:: no effects observed
: Key result
Dose descriptor:: LOAEC
Remarks:: local effects, adult rats
Effect level:: 750 ppm (nominal)
Sex:: male/female
Basis for effect level:: other: degeneration of the olfactory epithelium in the nasal cavity at 750 and 2000 ppm in F0 and F1 males and females (1500 ppm group not investigated)
Remarks on result:: other: Generation: F0, F1
: Key result
Dose descriptor:: NOAEC
Remarks:: systemic toxicity, adult rats
Effect level:: 750 ppm (nominal)
Sex:: male/female
Basis for effect level:: other: Decrements in mean body weights, body weight gains and/or food consumptions at 1500 and 2000 ppm
Remarks on result:: other: Generation: F0, F1, F2
: Key result
Dose descriptor:: NOAEC
Remarks:: developmental toxicity
Effect level:: 750 ppm (nominal)
Sex:: male/female
Basis for effect level:: other: see 'Remark'
Remarks on result:: other: Generation: F1, F2
: Key result
Dose descriptor:: NOAEC
Remarks:: fertility
Effect level:: 2 000 ppm (nominal)
Sex:: male/female
Basis for effect level:: other: No functional effects on reproduction (estrous cycles, mating and fertility indices, number of days between pairing and coitus, spermatogenic endpoints and gestation length) in any test article-exposed group in the F0 or F1 generations
Remarks on result:: other: Generation: F0, F1
Clinical signs:: no effects observed
Mortality / viability:: no mortality observed
Body weight and weight changes:: effects observed, treatment-related
Sexual maturation:: no effects observed
Organ weight findings including organ / body weight ratios:: effects observed, treatment-related
Gross pathological findings:: no effects observed
Histopathological findings:: not examined
: Key result
Dose descriptor:: NOAEC
Generation:: F1
Effect level:: 750 ppm (nominal)
Sex:: male/female
Basis for effect level:: other: growth retardation (lower pup bws and bw gains) and delays in attainment of developmental landmarks (secondary to reduced bw) at 1500 and 2000 ppm were only observed in association with maternal toxicity; no effects on fertility at any dose level.
Dose descriptor:: NOAEC
Generation:: F2
Effect level:: 750 ppm (nominal)
Sex:: male/female
Basis for effect level:: other: growth retardation (lower pup bws and bw gains) and delays in attainment of developmental landmarks (secondary to reduced bw) at 1500 and 2000 ppm were only observed in association with maternal toxicity; no effects on fertility at any dose level.
Reproductive effects observed:: not specified

Reference 2

Endpoint:: fertility, other
Type of information:: experimental study
Adequacy of study:: weight of evidence
Reliability:: 2 (reliable with restrictions)
Rationale for reliability incl. deficiencies:: study well documented, meets generally accepted scientific principles, acceptable for assessment
Remarks:: males were exposed only 6 weeks prior to mating compared to the 10 weeks recommended by the guidelines 415 and 416 but sufficiently long enough if compared to the screening test (guideline 421) which recommends only 2 weeks of exposure prior to mating. Older male rats were used as can be extrapolated from the initial body weights whereas younger rats are recommended in the guidelines
Principles of method if other than guideline:: Behavioural peri-, postnatal develpomental (neuro)toxicity study. Two concentrations of butan-1-ol (3000 and 6000 ppm) were administered by inhalation to separate groups of 15 pregnant Sprague-Dawley rats for 7 hr per day throughout gestation ; 18 male rats were similarly exposed for 7 hr per day for 6 weeks, and mated to unexposed females.
GLP compliance:: no
Species:: rat
Strain:: Sprague-Dawley
Sex:: male/female
Details on test animals or test system and environmental conditions:: TEST ANIMALS
- Weight at study initiation: (P) Males: mean: 429-512 g; Females: mean: no data

ENVIRONMENTAL CONDITIONS
no data
Route of administration:: inhalation: vapour
Type of inhalation exposure (if applicable):: not specified
Vehicle:: other: air
Analytical verification of doses or concentrations:: yes
Details on analytical verification of doses or concentrations:: Concentrations measured in the exposure chambers approximated the target concentrations of 3000 and 6000 ppm. Mean (±s.d.) 1-butanol concentrations were 3010 (±50) and 6000 (±80) ppm, and results of periodic confirmatory charcoal tube samples were 3000 (± 90) and 5960 (± 110) ppm, respectively .
Duration of treatment / exposure:: females: Exposure period: day 1 - 20 of gestation
males: 6 weeks before mating
Frequency of treatment:: 7 h/d
Dose / conc.:: 0 ppm (nominal)
Dose / conc.:: 3 000 ppm (nominal)
Dose / conc.:: 6 000 ppm (nominal)
No. of animals per sex per dose:: 15 females per dose
18 males per dose
Control animals:: yes
Statistics:: Data were analyzed using multivariate analysis of variance (MANOVA) on tests with multiple dependent measures, followed by analysis of variance (ANOVA) on each dependent variable if a significant MANOVA was observed. If only one dependent variable was obtained, ANOVA was used, followed by the Tukey Range Test to determine which cell means differed from one another.
: Key result
Dose descriptor:: NOAEL
Effect level:: 18.5 mg/L air
Based on:: test mat.
Sex:: male/female
Basis for effect level:: other: no effects observed
: Key result
Dose descriptor:: other: NOAEL developmental neurotoxicity
Generation:: F1
Effect level:: 18.5 mg/L air
Based on:: test mat.
Sex:: male/female
Basis for effect level:: other: no effects observed
Reproductive effects observed:: not specified

Reference 3

Endpoint:: fertility, other
Type of information:: experimental study
Adequacy of study:: weight of evidence
Reliability:: 2 (reliable with restrictions)
Rationale for reliability incl. deficiencies:: study well documented, meets generally accepted scientific principles, acceptable for assessment
Remarks:: the female rats were exposed for 8 weeks prior to mating which is in line with the guideline which recommends an exposure of two complete oestrous cycles prior to mating, however the animal numbers of 11-17 females per dose group were lower than recommended in the guidelines 415 and 416 but higher than recommended in the screening test (guideline 421).
Principles of method if other than guideline:: Female rats were given aqueous solutions of n-butanol containing 0.24, 0.8 and 4% n-butanol (0.3; 1.0 and 5.0 g/kg/day) for 8 weeks before and during gestation. The control animals received tap water. The experiment was performed in two stages. The first comprised of the assessment of the oestrous cycle before exposure and then during 4-5 and 7-8 weeks of exposure, and the second stage of the fertility of female rats and their foetal development.
GLP compliance:: no
Species:: rat
Strain:: not specified
Sex:: female
Details on test animals or test system and environmental conditions:: TEST ANIMALS
- Source: Own breeding colony (Imp:DAK)
- Age at study initiation: (P) females: 10 wks; (untreated males: 17 weeks)
- Weight at study initiation: (P) Females: 180-200 g
- Diet: ad libitum
- Water: ad libitum
- Acclimation period: no data

ENVIRONMENTAL CONDITIONS
- Temperature (°C): ca. 22 °C
- Humidity (%): 45-55 %
- Photoperiod (hrs dark / hrs light): 12/12
Route of administration:: oral: drinking water
Vehicle:: water
Details on exposure:: PREPARATION OF DOSING SOLUTIONS:
the test substance was mixed with drinking water, the stability of the aqueous n-butyl alcohol solutions was assessed on several consecutive days
Details on mating procedure:: - M/F ratio per cage: no data
- Length of cohabitation: 3 weeks with untreated males
- Proof of pregnancy: [sperm in vaginal smear] referred to as [day 0] of pregnancy
- After successful mating each pregnant female was caged (how): no data
Analytical verification of doses or concentrations:: yes
Details on analytical verification of doses or concentrations:: The stability of the aqueous n-butyl alcohol solutions was assessed on several consecutive days after their preparation using a Varian Aerograph 2800 gas chromatograph equipped with FID. The column was glass (2 in x 2 mm id .) packed with Porapak Q. The operating conditions were: carrier gas flow (nitrogen) 30 cm3/min; hydrogen 30 cm3/min; air 300 cm3/min; the temperature of the column, injection part and detector were 200°C, 200°C, 230°C, respectively. It was determined that the aqueous n-butyl alcohol solutions were stable within the concentration range used in the experiment (0.24-4%).
Duration of treatment / exposure:: Exposure period: 8 weeks premating, mating (max. 3 weeks) , gestation day 0 - 20
Frequency of treatment:: daily, continuous
Dose / conc.:: 300 mg/kg bw/day (nominal)
Remarks:: 0.24% in water
Dose / conc.:: 1 000 mg/kg bw/day (nominal)
Remarks:: 0.8% in water
Dose / conc.:: 5 000 mg/kg bw/day (nominal)
Remarks:: 4% in water
No. of animals per sex per dose:: 11-17 females per dose
Control animals:: yes, concurrent vehicle
Parental animals: Observations and examinations:: CAGE SIDE OBSERVATIONS: Yes
- Time schedule: The general behaviour of the animals was observed throughout the experiment.

DETAILED CLINICAL OBSERVATIONS: No data

BODY WEIGHT: Yes
- Time schedule for examinations: Weight gain was monitored every week in the nonpregnant females and on days 3, 7, 10 and 17 of gestation in the pregnant animals

FOOD CONSUMPTION:
- The daily intake of food was monitored every week in the nonpregnant females and on days 3, 7, 10 and 17 of gestation in the pregnant animals.

WATER CONSUMPTION AND COMPOUND INTAKE (if drinking water study): Yes
- Time schedule for examinations: The daily intake of water or n-butanol solutions was monitored every week in the nonpregnant females and on days 3, 7, 10 and 17 of gestation in the pregnant animals.
Oestrous cyclicity (parental animals):: Vaginal smears to assess the oestrous cycle were taken daily between 8 a.m. and 10 a.m. in all animals for 14 consecutive days before exposure and then during the 4-5 and the 7-8 the weeks of exposure. Smears were stained by the Shorr method.
Postmortem examinations (parental animals):: SACRIFICE
- Maternal animals: All surviving animals [on day 20 of gestation]

GROSS NECROPSY
not specified

HISTOPATHOLOGY / ORGAN WEIGHTS
not specified
Statistics:: In the case of variance homogeneity, one-way variance analysis and Dunnett tests were used in the case of heterogeneity Kruskal-Wallis variance analysis was followed by non-parametric tests. Frequency data was analyzed with a Fisher exact probability test. The consumption of food and water or n-butanol solution, and body weight gain of dams were evaluated with two-way variance analysis and Scheffe test for multiple comparison.
: Key result
Dose descriptor:: NOAEL
Remarks:: systemic toxicity and fertility
Effect level:: 5 000 mg/kg bw/day
Based on:: test mat.
Sex:: female
Basis for effect level:: other: no effects observed
Dose descriptor:: LOEL
Effect level:: 300 mg/kg bw/day (actual dose received)
Sex:: male/female
Basis for effect level:: other: dilation of the subarachnoid space and lateral ventricle and/or third ventricle of the brain
Reproductive effects observed:: not specified

Reference 4

Endpoint:: toxicity to reproduction
Remarks:: other: repeated dose toxicity, subchronic
Type of information:: experimental study
Adequacy of study:: weight of evidence
Reliability:: 1 (reliable without restriction)
Rationale for reliability incl. deficiencies:: comparable to guideline study
Reason / purpose for cross-reference:: reference to same study
Principles of method if other than guideline:: Four groups of male and female rats (30/sex/group) were administered daily by gavage 0, 30, 125 or 500 mg/kgbw/d for either 6 or 13 weeks.
GLP compliance:: yes
Limit test:: no
Species:: rat
Strain:: Sprague-Dawley
Sex:: male/female
Details on test animals or test system and environmental conditions:: see IUCLID chapter 7.5.1
Route of administration:: oral: gavage
Details on exposure:: see IUCLID chapter 7.5.1
Details on mating procedure:: no mating
Analytical verification of doses or concentrations:: yes
Duration of treatment / exposure:: 6 (interim sacrifice) or 13 weeks
Frequency of treatment:: daily
Dose / conc.:: 0 mg/kg bw/day (actual dose received)
Dose / conc.:: 30 mg/kg bw/day (actual dose received)
Dose / conc.:: 125 mg/kg bw/day (actual dose received)
Dose / conc.:: 500 mg/kg bw/day (actual dose received)
No. of animals per sex per dose:: 30
Control animals:: yes, concurrent vehicle
Parental animals: Observations and examinations:: see IUCLID chapter 7.5.1
Postmortem examinations (parental animals):: At the interim and final sacrifice, testes (with epididymes) and ovaries were weighed. Testis (with epididymis), ovary, uterus and cervix were part of the histological examinations.
Dose descriptor:: NOEL
Effect level:: 500 mg/kg bw/day (actual dose received)
Based on:: test mat.
Sex:: male/female
Basis for effect level:: other: no adverse effects observed on reproductive organs
Remarks on result:: not measured/tested
Reproductive effects observed:: not specified

Effect on fertility: via oral route

Endpoint conclusion:: no adverse effect observed
Dose descriptor:: NOAEL
: 500 mg/kg bw/day
Study duration:: subchronic
Species:: rat
Quality of whole database:: comparable to guideline study under GLP conditions

Effect on fertility: via inhalation route

Endpoint conclusion:: no adverse effect observed
Dose descriptor:: NOAEC
: 6 189 mg/m³
Study duration:: subchronic
Species:: rat
Quality of whole database:: Giudeline study under GLP conditions (calculated from NOAEC of 2000 ppm for butyl acetate)

Effect on fertility: via dermal route

Endpoint conclusion:: no study available

Additional information

Oral:

Within a GLP conform subchronic repeated dose toxicity study, effects on reproductive organs (testes with epididymes, ovaries) were studied (US EPA 1986, see also section repeated dose toxicity). In this study, four groups of male and female Sprague-Dawley rats (30/sex/group) were administered daily 0, 30, 125 or 500 mg/kg bw/d by gavage for either 6 or 13 weeks. No dose-related differences were observed between treatment or control rats with regards to reproductive organs up to the highest dose. Thus, the NOEL for reproductive organ toxicity was 500 mg/kg bw/d (for futher details on the study, please refer to the section: repeated dose toxicity).

In an explorative study to investigate the effect of Butan-1-ol on fertility and prenatal development, female Imp:DAK rats (undefined strain of test facility´s own breeding colony, Lodz, Poland) in groups of 11 - 17 animals were exposed via the drinking water at concentrations of 0, 0.24, 0.8 and 4% (corresponding to about 0, 300, 1000 and 5000 mg/kg bw/d) for 8 weeks (Sitarek, 1994). Oestrus cyclicity was evaluated before and during the whole exposure period. After an 8 week exposure period the females were mated with untreated males for a maximum of 3 weeks. Dosing of the females continued through pairing and gestation until the animals were killed on day 20 of gestation, when uterine contents were examined and foetuses were collected to be investigated for skeletal and visceral effects. No effects were noted for general toxicity in the form of impaired general appearance, food consumption, body weight/weight gain,absolute and relative organ weight, haemoglobin concentration, haematocrit values. Fertility and developmental parameters in the form of number and length of oestrous cycles, corpora lutea, total implants, intra-uterine mortality, foetal body weights and placental weight were not affected by Butan-1-ol exposure. The NOAEL for maternal toxicity including fertility was 5000 mg/kg bw/d (for further details on study, please refer to the section developmental toxicity).

Inhalation:

Butan-1-ol was investigated for its possible behavioral developmental neurotoxicity in a scientifically reliable study in rats following in utero or paternal inhalation exposure (Nelson 1989). Groups of 15 pregnant female Sprague-Dawley rats were exposed to 0, 3000, or 6000 ppm (0, 9.2 mg/L or 18.5 mg/L) for 7 hours/day on GDs 1 – 19. Groups of 18 male Sprague-Dawley rats were exposed to the same concentrations for 7 hours/day for 6 weeks and then mated to non-exposed females. On the day of birth (PND 0), offspring were culled to four males and four females per litter and fostered to untreated controls. No effects on maternal or parental general toxicity and no effects on the pregnancy rate after either maternal or paternal exposure were reported up to the highest concentration. Thus, 6000 ppm (18.5 mg/L) was a NOAEC for parental toxicity including fertility (for further details on study, please refer to the section developmental toxicity).

Two-generation reproduction toxicity study with the read across substance n-Butyl acetate

A two-generation reproduction toxicity study was performed according to OECD TG 416 and OPPTS TG 870.3800 under GLP conditions in rats exposed to n-Butyl acetate (Nemec, 2010).The study was conducted to evaluate the potential adverse effects of n-butyl acetate following inhalation exposure on reproductive capabilities, including gonadal function, estrous cyclicity, mating behavior, conception, gestation, parturition, lactation and weaning of the F0 and F1 generations and F1 and F2 neonatal survival, growth and development. Additionally, F2 weanlings were directly exposed to n-butyl acetate for approximately 7 weeks. One litter per dam was produced in each generation.

Four groups of male and female Crl:CD(SD) rats (30/sex/group) were exposed to either clean filtered air or vapor atmospheres of the test article, n-butyl acetate, for 6 hours daily for at least 70 consecutive days prior to mating. Target test article concentrations were 750, 1500 and 2000 parts per million (ppm) for the F0, F1 and F2 generations. Mean measured inhalation exposure concentrations were 749.4, 1495.8 and 2018.1 ppm for the F0 generation, 752.8, 1495.5 and 2008.1 ppm for the F1 generation and 760.8, 1506.3 and 2009.6 ppm for the F2 generation. Exposures were initiated when the F0 animals were approximately 7 weeks of age. Exposure of the F0 and F1 males continued throughout mating, and through the day prior to euthanasia. The F0 and F1 females continued to be exposed throughout mating and gestation through gestation day 20. Exposure was suspended from gestation day 21 through lactation day 4 to avoid the confounding effects on nesting and nursing behavior caused by separation of dams from their litters.

Therefore, on lactation days 1-4, the F0 and F1 maternal animals received deionized water (Group 1) or the test article (Groups 2-4) via oral gavage at dosage levels of 0, 1125, 2250 and 3000 mg/kg/day (0, 375, 750 and 1000 mg/kg/dose, respectively, administered as 3 equal doses, approximately 2 hours apart at dosage volumes of 1.13, 0.42, 0.85 and 1.13 mL/kg/dose, respectively), to mimic the internal dose expected from inhalation exposure. A specific gravity of 0.88 g/mL was used to calculate the equivalent volume for dosing. Inhalation exposure of the F0 and F1 females was re-initiated on lactation day 5 and continued through the day prior to euthanasia. Inhalation exposure of the F1 animals was initiated on PND 22 (2 weanlings/sex/litter, when possible), and in order to determine if differences from the control group in mean body weights, body weight gains

and food consumption noted in F1 males at 750 ppm during the post-weaning period were reproducible, F2 animals (2 weanlings/sex/litter, when possible) were directly exposed to the test article beginning on PND 22. Following approximately 2-3 weeks of exposure (PND 36-47) of the F1 generation and on PND 36 for the F2 generation, offspring (minimum of 1 animal/sex/litter, to a total of 30/sex/group) were selected for the maturation phase of each generation. F0 males and females were exposed for 113-114 and 121-127 consecutive days, respectively, and F1 males and females were exposed for 134-135 and 140-153 consecutive days, respectively. F2 males and females

were exposed for 47-50 consecutive days.

All animals were observed twice daily for appearance and behavior. Clinical observations, body weights and food consumption were recorded at appropriate intervals for males throughout the study and for females prior to mating and during gestation and lactation. Vaginal lavages were performed daily for determination of estrous cycles beginning 21 days prior to pairing. All F0 and F1 females were allowed to deliver and rear their pups until weaning on lactation day 21. Clinical observations, body weights and sexes for F1 and F2 pups were recorded at appropriate intervals. Developmental landmarks (pinnal detachment, incisor eruption, eye opening, balanopreputial separation and vaginal patency) were evaluated for the selected F1 and F2 rats. Nonselected F1 and F2 pups were necropsied on PND 21; the extra F1 and F2 litter mates that were exposed were necropsied following approximately 2-3 weeks of exposure or on PND 36, respectively. Selected organs were weighed from both F1 and F2 pups that were necropsied on PND 21. Each surviving F0 and F1 paternal animal received a detailed gross necropsy following completion of the parturition period. Each surviving F0 and F1 maternal animal received a detailed gross necropsy approximately 1 week following weaning of their respective litters, on post-mating day 25 (females that failed to deliver), on gestation days or post-cohabitation day 15 (females that did not have evidence of mating within 14 days) or within 24 hours of total litter loss. Each surviving F2 animal selected to continue exposure beyond PND 36 received a gross necropsy at approximately 10 weeks of age. Selected organs were weighed from all 3 generations. Spermatogenic endpoints (sperm motility including progressive motility, morphology and numbers) were recorded for all surviving F0 and F1 males, and ovarian primordial follicle counts were recorded for all F1 females in the control and high-exposure groups. Designated tissues from all F0 and F1 parental animals in the control and high-exposure groups were examined microscopically. In addition, the nasal passage tissues of F0 and F1 parental animals in the 750 ppm group were examined microscopically.

There were no test article-related mortalities in the adult animals of the F0, F1 and F2 generations; there were no clinical or macroscopic signs of toxicity for the test article-exposed animals. There were no indications of toxicity on reproductive function at any exposure level. In each generation evaluated, reproductive performance, parturition, the mean numbers of implantation sites, unaccounted-for sites at weaning and spermatogenic endpoints in the test article-exposed groups were similar to the respective control group. No test article-related macroscopic findings were observed for the reproductive tissues at any exposure level of all 3 generations, and there were no microscopic findings for these tissues at 750 and 2000 ppm in the F0 and F1 generations.

With regard to reproductive organ weights, a trend toward reduced mean absolute testicular weight was noted in the F1 parental and F2 males (examined at or nearing sexual maturity) exposed for 18 and 7 weeks, respectively, to atmospheres of 1500 and 2000 ppm n-butyl acetate. When compared to control values, mean final body weights were reduced from 18.6% to 22.6% and 6.7% to 13.3% at the end of the F1 and F2 generations, respectively. For F0 generation males, mean absolute testicular weights in the mid- and high-exposure groups were comparable with the control group following approximately 16 weeks of exposure despite 15.6% and 20.0%, respectively, lower mean final body weights.

These differences in gonadal weight among the 3 generations in the present study are most likely owing to the differences in the onset of exposure relative to age and subsequent specific life stage exposures unique to each generation. Signals of developmental delay (especially at 2000 ppm) at the onset of exposure in each generation coupled with 1) the sustained effects on growth throughout the generation, 2) the relationship of organ weight data normalized against body weight and brain weight are not consistent with a target organ effect, 3) the lack of changes in reproductive function, seminology and histopathology of these tissues and 4) evidence of growth inhibition in other organ systems in these animals collectively support the hypothesis that the testicular weight differences are non-specific, non-adverse and secondary to the test article-related effects on body weights.

No test article-related effects were observed on the mean numbers of F1 or F2 pups born, pup sex ratio, pup survival, the general physical condition of the pups during the pre-weaning period and developmental landmarks during the pre-weaning period. No test article-related macroscopic findings were noted in F1 or F2 pups at the scheduled necropsies; no test article-related macroscopic findings were noted for F1 or F2 pups that died during the postnatal period.

Test article-related histologic observations were limited to degeneration of the olfactory epithelium in the nasal cavity in both parental generations. Lesions were observed in a gradient fashion, i.e., were the most severe and widely distributed at level II, with decreased incidence, severity and distribution moving caudally within the nasal cavity.

Lesion incidence, distribution and severity increased between 750 and 2000 ppm. This finding was considered a site-of-contact irritant effect.

Test article-related differences in weights of organs not related to reproduction were limited to higher mean relative (to final body weight) lung weights in F0 males at 1500 and 2000 ppm, in F1 males at 750, 1500 and 2000 ppm and in F0 females at 2000 ppm, although absolute lung weights for F0 males at 2000 ppm and F1 males at 1500 and 2000 ppm and lung weight relative to brain weight for F1 males at 2000 ppm were lower than controls. Increases in adrenal weights (absolute, relative to brain weight, and relative to body weight) as compared to control article-exposed F0 animals were also observed in both the 1500 and 2000 ppm groups for F0 females. No microscopic correlates to these altered organ weights were identified. Several other differences in mean organ weights were noted in the F0, F1 and F2 adults but were considered secondary to lower mean final body weights.

Decreases in mean weekly food consumption were noted for the males and females in the 1500 ppm/2250 mg/kg/day and 2000 ppm/3000 mg/kg/day groups of the F0, F1 and/or F2 generations generally throughout the pre-mating, post-mating (males only) and entire direct exposure periods compared to the respective control groups. These decreases in food consumption generally corresponded to decreases in mean body weights, body weight gains and cumulative body weight gains throughout these periods. The effects on mean weekly body weights and food consumption were generally more pronounced in the males than the females and more sustained in duration at 2000 ppm/3000 mg/kg/day than at 1500 ppm/2250 mg/kg/day. Mean food consumption and body weight gains in the 1500 ppm/2250 mg/kg/day and 2000 ppm/3000 mg/kg/day groups were generally slightly decreased during gestation and were generally unaffected during lactation in both the F0 and F1 generations.

In contrast, the lower mean weekly food consumption and body weights gains in the 750 ppm/1125 mg/kg/day group males and females were not observed across the 3 generations and were, therefore, not considered related to test article exposure. Mean food consumption and body weight gains in the 750 ppm/1125 mg/kg/day group of the F0 and F1 generations were unaffected by test article exposure during both gestation and lactation. Lower mean pup body weights were noted in the F1 and F2 male and female pups in the 2000 ppm group on PND 1 and PND 4. Although the differences in mean pup body weights were statistically significant only for the F1 female pups, the lower mean pup body weights in the F1 male pups and F2 male and female pups were also considered biologically significant. The mean pup body weights in the F1 and F2 male and female pups in the 1500 ppm group on PND 1 and PND 4 were similar to the values for the control group. Mean pup body weight gains in the F1 male and female pups in the 1500 and 2000 ppm groups were not statistically significantly different than control values from PND 1-4 and PND 4-7, although the changes in the 2000 ppm group from this generation were considered lower than the control group values. Mean pup body weight gains in the F2 male and female pups in the 1500 and 2000 ppm groups were not affected from PND 1-4 and were lower during the PND 4-7 time period, coinciding with the separation of the dams with the pups for inhalation exposures. Mean pup body weight gains in the male and female pups in the 1500 and 2000 mg/kg/day groups were lower from PND 7-14 (F1) and from PND 7-21 (F2), although interpretation of the latter time period is confounded by the pups starting to eat solid feed. Differences in organ weights on PND 21 were also noted at 1500 and 2000 ppm in the F1 and F2 pups as a result of these decrements in pup body weights and body weight gains. An exception is the significantly lower thymus weights (absolute, relative to final body and/or brain weights) that were noted in the 1500 and 2000 ppm groups for both males and females in both the F1 and F2 generations at PND 21. The decrease in thymus weights was not replicated in

the necropsy of the F2 pups following 7 weeks of inhalation exposure.

The test article-related lower mean body weights during the period of growth and development of the F1 and F2 generations resulted in higher mean ages of attainment of balanopreputial separation for the F1 and F2 males at 2000 ppm and vaginal opening for F2 females at 2000 ppm, as delays in attainment of these landmarks have been associated with decreased mean body weights (Carney et al.,Toxicological Science 2004,82, 237-249). Additionally, lower mean body weights on the day of attainment for these males and females, as well as for those of the F1 males at 1500 ppm and of the F1 females at 1500 and 2000 ppm, were consistent with the lower mean body weights noted in these groups throughout the pre- and post-weaning periods.

There were no functional effects on reproduction (estrous cycles, mating and fertility indices, number of days between pairing and coitus, spermatogenic endpoints and gestation length) in any test article-exposed group in the F0 or F1 generations. Adverse effects on pups born to dams exposed to the test article were limited to exposure-related growth retardation, as evidenced by lower mean pup body weights, body weight gains and absolute organ weights on PND 21 at 1500 and 2000 ppm; delays in attainment of post-weaning developmental landmarks were also observed at 2000 ppm. Significantly lower thymus weights (absolute, relative to final body and/or brain weight) were also noted in both juvenile F0 and F1 generations at 1500 and 2000 ppm for both males and females at PND 21 (without correlating histologic findings), although the thymus weights

of the F2 pups exposed for 7 weeks by inhalation were unaffected. F1 and F2 pup survival was unaffected by the test article at all exposure levels. Therefore, in this study an exposure level of 750 ppm was considered to be the no-observed-adverse-effect level (NOAEL) for developmental and neonatal toxicity when n-butyl acetate was administered via whole body inhalation to Crl:CD(SD) rats. However, as these effects were associated with clear maternal toxicity at 1500 and 2000 ppm, they are not considered as an independent effect. Effects on fertility and reproductive performance were not observed up to the highest dose tested. The no-observed-adverse-effect level (NOAEL) for fertility and reproductive performance was thus 2000 ppm.

General systemic toxicity was evident in the 1500 and 2000 ppm group F0, F1 and F2 adult males and females. Decrements in mean body weights, body weight gains and food consumption were observed at 1500 and 2000 ppm. Although body weights, body weight gains and food consumption were reduced in the 750 ppm males of the F1 generation, direct inhalation exposure of F2 animals on a comparable regimen did not reproduce this response. Additionally, the magnitude and temporal pattern of the reductions in the F1 males at 750 ppm were not noted in the F0 generation. Therefore, mean body weights, body weight gains and food consumption at 750 ppm were considered to be unaffected by test article exposure. Degeneration of the olfactory epithelium in the nasal cavity was noted at 750 and 2000 ppm in F0 and F1 males and females. This finding was considered to be a site-of-contact irritant effect and not indicative of systemic toxicity. Statistically significantly higher mean lung weights (relative to final body weight) in F0 males at 1500 and 2000 ppm, in F1 males at 750, 1500 and 2000 ppm and in F0 females at 2000 ppm and adrenal weights (absolute, relative to brain and body weight) in F0 females at 1500 and 2000 ppm were also noted in adult animals; all were observed without correlating histologic findings and were considered a stress-related response (adrenal weights) or not adverse (lung weights).

Therefore, the NOAEL for systemic toxicity in adult rats was considered to be 750 ppm under the conditions of this study, a NOAEL for local irritant effects in the respiratory tract could not be established.

3 -month subchronic inhalationstudy with n-Butyl acetate

Additional supportive evidence that there is no effect on male reproductive organs comes from the subchronic inhalation toxicity study performed according to EPA guideline OTS 798.2450 (OPP/CMA 94030517, 1996). In this study the exposure to groups of 15 male and 15 female Sprague-Dawley rats of about 0, 2.35, 7.05 and 14.1 mg/L n-Butyl acetate (i.e. 0, 500, 1500 and 3000 ppm) for 6 hours per workday within 13 week showed no effects up to 3,000 ppm on homogenisation-resistant spermatid head counts from both the testes and the epididymides and on reproductive organ histopathology (for further details on this study, please refer to the endpoint summary: repeated dose toxicity).

Effects on developmental toxicity

Description of key information

Oral

Prenatal developmental toxicity study, rat: NOAEL maternal and developmental toxicity: 1454 mg/kg bw/d, no teratogenicity observed up to the highest dose (5654 mg/kg/day) tested (Ema 2005, RL 1).

Explorative study on female fertility and prenatal development, rat: The NOAEL maternal toxicity and teratogenicity: 5000 mg/kg bw/d. A NOEL for developmental effects was not established (Sitarek 1994, RL2).

Inhalation

Prenatal developmental toxicity study, rat, NOAEC maternal toxicity and developmental toxicity including morphological fetal alterations: 3500 ppm (10.8 mg/L, Nelson 1989a, RL 2)

Behavioural peri-, postnatal developmental (neuro)toxicity study, rat, NOAEC parental including behavioural or teratogenic effects = 6000 ppm (18.5 mg/L, Nelson 1989b, RL 2)

n-Butyl acetate inhalation

Prenatal developmental toxicity study, rabbit: NOAEC maternal and developmental toxicity 1500 ppm (7.2 mg/L, Hackett/Battelle 1982a, RL 1).

Prenatal developmental toxicity study, rat: LOAEC maternal and developmental toxicity 1500 ppm (7.2 mg/L, Hackett/Battelle 1982b, RL 1). The developmental effects were associated with clear maternal toxicity they are not considered as an independent effect.

Prenatal developmental toxicity study, rat: NOAEC maternal toxicity: 500 ppm (2.4 mg/L), NOAEC developmental toxicity 2000 ppm (9.6 mg/L, Saillenfait et al., 2007, RL2).

Link to relevant study records

Referenceopen all close all

Reference 1

Endpoint:: developmental toxicity
Type of information:: experimental study
Adequacy of study:: key study
Reliability:: 1 (reliable without restriction)
Rationale for reliability incl. deficiencies:: guideline study
Qualifier:: according to guideline
Guideline:: other: Ministry of Health and Welfare, Japan; Guidelines for Toxicity Studies of Drugs
Qualifier:: equivalent or similar to guideline
Guideline:: OECD Guideline 414 (Prenatal Developmental Toxicity Study)
Principles of method if other than guideline:: Pregnant rats were given drinking water containing 1-butanol at 0.2%, 1.0% or 5.0% (316, 1454 or 5654 mg/kg/day) on days 0–20 of pregnancy. The rats were sacrificed on day 20 of pregnancy and both the dams and fetuses were examined.
GLP compliance:: yes
Species:: rat
Strain:: Crj: CD(SD)
Details on test animals or test system and environmental conditions:: TEST ANIMALS
- Source: Tsukuba Breeding Center
- Age at study initiation: males: 10 weeks; females: 9 weeks
- Weight at study initiation: females: 217-273 g
- Housing: individually
- Diet: ad libitum
- Water: ad libitum
- Acclimation period: 7 days

ENVIRONMENTAL CONDITIONS
- Temperature (°C): 21-25 °C
- Humidity (%): 40-70 %
- Photoperiod (hrs dark / hrs light): 12/12
Route of administration:: oral: drinking water
Vehicle:: water
Details on exposure:: PREPARATION OF DOSING SOLUTIONS:
1-butanol was mixed with water to the according target concentrations. The stability of formulations in a dark and cool place under airtight conditions has been confirmed for up to 3 days. During use, the formulations were maintained under such conditions for no more than 3 days and were 95.7–103.5% of the target concentration.
Analytical verification of doses or concentrations:: yes
Details on analytical verification of doses or concentrations:: The concentrations were determined analytically and were 95.7–103.5% of the target concentration.
Details on mating procedure:: - Impregnation procedure: [cohoused]
- If cohoused:
- M/F ratio per cage: 1/1
- Length of cohabitation: over night
- Verification of same strain and source of both sexes: [yes]
- Proof of pregnancy: [sperm in vaginal smear] referred to as [day 0] of pregnancy
Duration of treatment / exposure:: day 0 through day 20 of pregnancy
Frequency of treatment:: continuous through drinking water
Duration of test:: until day 20 of pregnancy
No. of animals per sex per dose:: 20 females per dose
Control animals:: yes, concurrent vehicle
Details on study design:: - Dose selection rationale: The dosage levels were determined based on the results of our range-finding study in which administration of 1-butanol in the drinking water on days 0–20 of pregnancy caused decreases in maternal body weight gain and food and water consumption and tended to reduce in fetal weight at 4% and 7% in rats.
Maternal examinations:: CAGE SIDE OBSERVATIONS: Yes
- Time schedule: not specified

DETAILED CLINICAL OBSERVATIONS: Yes
- Time schedule: not not specified

BODY WEIGHT: Yes
- Time schedule for examinations: once daily

FOOD CONSUMPTION: Yes
- Time schedule for examinations: every 3 or 4 days

WATER CONSUMPTION AND COMPOUND INTAKE (if drinking water study): Yes
- Time schedule for examinations: daily

POST-MORTEM EXAMINATIONS: Yes
- Sacrifice on gestation day # 10
- Organs examined: not specified
Ovaries and uterine content:: The ovaries and uterine content was examined after termination: Yes
Examinations included:
- Gravid uterus weight: No data
- Number of corpora lutea: Yes
- Number of implantations: Yes
- Number of early resorptions: Yes
- Number of late resorptions: Yes
Fetal examinations:: - External examinations: Yes: [all per litter]
- Soft tissue examinations: Yes: [half per litter]
- Skeletal examinations: Yes: [half per litter]
- Head examinations: Yes: [half per litter]
Statistics:: The statistical analysis of fetuses was carried out using the litter as the experimental unit. The initial body weight, body weight gain and food and water consumption of pregnant rats, numbers of corpora lutea, implantations and live fetuses per litter, fetal weight and crown-rump length and placental weight were analyzed with Bartlett's test for homogeneity of variance at the 5% level of significance.
If it was homogeneous, the data were analyzed using Dunnett's multiple comparison test to compare the mean of the control group with that of each dosage group, and if it was not homogeneous, the mean rank of the 1-butanol-treated groups was compared with that of the control group with the Dunnett type test. The Dunnett type test was used for the incidences of pre- and postimplantation embryonic loss and fetal anomalies and sex ratio of fetuses to compare the mean rank of groups treated with 1-butanol and that of the control group. The incidence of dams with anomalous fetuses was analyzed by Chi-square test or Fisher's exact test. The significance of differences from the control group was estimated at probability levels of 1% and 5%.
Indices:: no data
Historical control data:: International Genetic Standard (Crj: CD (SD) IGS) rats were used throughout this study. This strain was chosen because it is most commonly used in reproductive and developmental toxicity studies and historical control data are available.
Details on maternal toxic effects:: Details on maternal toxic effects:
No death was found in female rats of any group. All females in all groups became pregnant. The body weight gains on days 0–7 of pregnancy were significantly reduced at 5.0%. The body weight gain during the whole period of pregnancy was also significantly decreased at 5.0%. No significant decrease in the body weight gain was noted at 0.2 or 1.0, except for a transient decrease on days 0–2 of pregnancy at 1.0%. The food consumption on days 0–7, days 7–14, days 14–20 and days 0–20 of pregnancy was significantly lower in the 1.0% and 5.0% groups than the control group. The water consumption on days 0–7 at 1.0 and 5.0% and on days 7–14, days 14–20 and days 0–20 at 5.0% was significantly decreased. The mean daily intakes of 1-butanol were 316 mg/kg for the 0.2% group, 1454 mg/kg for the 1.0% group and 5654 mg/kg for the 5.0% group.
: Key result
Dose descriptor:: NOAEL
Remarks:: maternal toxicity
Effect level:: 1 454 mg/kg bw/day (nominal)
Based on:: test mat.
Basis for effect level:: other: maternal toxicity
Details on embryotoxic / teratogenic effects:: Details on embryotoxic / teratogenic effects:
No litters totally resorbed were found in any group. No effects of the administration of 1-butanol were observed on the numbers of corpora lutea, implantations, pre- or postimplantation loss, resorptions or dead or live fetuses or sex ratio of live fetuses. The body weights of male and female fetuses were significantly lower in the 5.0% group than in the control group. There was no significant difference in the crown-rump length of male and female fetuses or placental weight between the control and groups treated with 1-butanol.
One fetus with spina bifida in the control group and one fetus with thread-like tail and anal atresia in the 0.2% group were observed. Skeletal examination revealed one fetus with supernumerary thoracic vertebral bodies and malpositioned thoracic vertebrae at 1.0%. Although the total number of fetuses with skeletal variations was significantly increased at 5.0%, the number of fetuses with individual skeletal variations was not significantly increased, except for fetuses with short supernumerary ribs at 5.0%. A significantly lower number of forepaw proximal phalanges was observed at 5.0%. Membranous ventricular septum defect occurred in one fetus of the control and 0.2% groups and 3 fetuses in 3 dams of the 5.0% group. One fetus with a double aorta in the control group and one fetus with a left umbilical artery in the control and 2.0% groups were observed. Thymic remnants in the neck were found in 4–11 fetuses of the control and groups treated with 1-butanol.
However, there was no significant difference in the incidence of fetuses with internal abnormalities between the control and groups treated with 1-butanol.
: Key result
Dose descriptor:: NOAEL
Remarks:: teratogenicity
Effect level:: 5 654 mg/kg bw/day (nominal)
Based on:: test mat.
Basis for effect level:: other: teratogenicity
: Key result
Dose descriptor:: NOAEL
Remarks:: developmental toxicity
Effect level:: 1 454 mg/kg bw/day (nominal)
Based on:: test mat.
Basis for effect level:: other: fetotoxicity
Abnormalities:: not specified
Developmental effects observed:: not specified

Reference 2

Endpoint:: developmental toxicity
Type of information:: experimental study
Adequacy of study:: key study
Study period:: year of publication: 1982
Reliability:: 1 (reliable without restriction)
Rationale for reliability incl. deficiencies:: comparable to guideline study
Reason / purpose for cross-reference:: reference to same study
Qualifier:: equivalent or similar to guideline
Guideline:: OECD Guideline 414 (Prenatal Developmental Toxicity Study)
Deviations:: yes
Remarks:: : e.g. additional exposure during pregestation period
GLP compliance:: yes
Limit test:: yes
Species:: rabbit
Strain:: New Zealand White
Details on test animals or test system and environmental conditions:: TEST ANIMALS
- Source: R&R Rabbitry (Stanwood, WA)
- Age at study initiation: females: 5-6 month; males: 6-7 month
- Weight at study initiation: females: about 3 kg; males: about 3-4 kg
- Fasting period before study: none
- Housing: individually in stainless steel cages
- Diet: Wayne Rabbit Diet, ad libitum except during the exposure periods
- Water: ad libitum except during the exposure periods
- Acclimation period: no data
- Does were isolated for 24 daysbefore the initiation of exposure to obviate the possibility of pseudopregnancy.
- Rabbits were removed from the chamber and housed in other caging between exposure periods.
Route of administration:: inhalation: vapour
Type of inhalation exposure (if applicable):: whole body
Vehicle:: unchanged (no vehicle)
Details on exposure:: GENERATION OF TEST ATMOSPHERE / CHAMBER DESCRIPTION
- Exposure apparatus: stainless steel chamber (U.S. patent # 4,216,741)
- Method of holding animals in test chamber: in stainless steel cages
- Source and rate of air: HEPA-filtered air
- Method of conditioning air: test item vapour introduced into the filtered air system
- System of generating vapours: Liquid was pumped from a liquid reservoir to the vaporizer. Nitrogen was used to replace the depleted liquid in the reservoir, to prevent formation of an explosive mixture. The vaporizer consisted of a stainless stell cylinder covered with a glass-fiber wick from which the liquid was vaporized. An 80-watt heater and a temperature-sensi element were incorporated within the cylinder and connected to a remote temperature controller. Vaporizer surface temperatures were set ag about 80°C. Each cylindrical vaporizer was positioned in the fresh-air duct leading directly into ghe exposure chamber to minimize mateila loss due to condensation on duct walls. The vapour generation system was capabel of vapourizing up to 7 ml/min of liqquid into 280 L/min fresh air to produce vapour concentrations as high as 9000 ppm. The system maintained the required chamber concnetrations of 1500 ppm n-butyl acetate withing +/- 3% of target concentration.
- Temperature, humidity, pressure in air chamber: 23-27°C, 40-60% RH, -0.3 to -2.0 cm H2O (relative to room)
- Air flow rate: 560 L/min
- Treatment of exhaust air: Exhaust was pumped from the chamber through a flow monitor and into the building exhaust system. The exhaust from exposure rooms was diluted with the building exhaust prior to release form the building stack to produce environmenally acceptable stack concentrations.
- at the end of the exposure period the exposure chambers were flushed with fresh air for at least 2 h

TEST ATMOSPHERE
- Brief description of analytical method used: GC/FID analysis with n-nonane as internal standard
- Samples taken from breathing zone: no
Analytical verification of doses or concentrations:: yes
Details on analytical verification of doses or concentrations:: - chamber monitoring system for constant collection of fresh samples
- GC/FID analysis
- target mean daily concentration of n-butyl acetate in the exposure chambers was 1500 +/- 150 ppm
Details on mating procedure:: - Impregnation procedure: artificial insemination;
One third of each group was artificially inseminated in the afternoon of each day during a 3 day period. On the day of artificial insemination semen samples were collected from at least 3 bucks. To induce ovulation the does were administered chorionic gonadotropin at a dose level of 100 USP units/doe. The morning following insemination was designated as day 1 of gestation.
Duration of treatment / exposure:: 7 h/d on the designated gestation days
Frequency of treatment:: Exposure schedule

Days of gestation
Group 1 to 6 7 to 19 20 to 29 30
1 Filtered air Filtered air No exposure Sacrifice
2 Filtered air Test chemical No exposure Sacrifice
3 Test chemical Test chemical No exposure Sacrifice

pregestation exposure period: 3 weeks
Duration of test:: 30 days
Dose / conc.:: 1 500 ppm (nominal)
No. of animals per sex per dose:: group 1: 30 inseminated; 22 pregnant at sacrifice
group 2: 30 inseminated; 21 pregnant at sacrifice
group 3: 30 inseminated; 25 pregnant at sacrifice
Control animals:: yes, sham-exposed
Details on study design:: positive control group:
- Six does were assigned to the positive control group. They received a single intraperitoneal injection of the known teratogenic substance 6-aminonicotinamide on gestation day 9 (3 mg/kg)
Maternal examinations:: CAGE SIDE OBSERVATIONS: Yes
- Time schedule: no data, probably daily

DETAILED CLINICAL OBSERVATIONS: No

BODY WEIGHT: Yes
- Time schedule for examinations: on day 1, 5, 10, 15, 20 and 25 of gestation

FOOD CONSUMPTION AND COMPOUND INTAKE (if feeding study): Yes
- Time schedule for examinations: for 2 weeks prior to the initiation of exposure and over 5-day intervals during gestation

WATER CONSUMPTION AND COMPOUND INTAKE (if drinking water study): No data

POST-MORTEM EXAMINATIONS: Yes
- Sacrifice on gestation day 30
- organ weight: liver, lung, spleen, kidneys, ovaries, uteri
- organs for histopathologic investigations: ovaries, uteri, liver, lungs with trachea, spleen, kidneys and any grossly abnormal tissue; tissues from 25% of the females (a maximum of 8 per group) and any grossly abnormal tissues were processed by routine techniques (paraffin embedding, hematoxylind and eosin staining) and subjected to histopathologcal examination
- observations internal abnormalities in pregnant and nonpregnant animals were recorded (e.g. adhesions, tumors, evidence of infection)
Ovaries and uterine content:: The ovaries and uterine content was examined after termination: Yes
Examinations included:
- Gravid uterus weight: Yes
- Number of corpora lutea: Yes
- Number of implantations: Yes
- Number of early resorptions: Yes
- Number of late resorptions: Yes
- Other:
- uteri of all apparent nonpregnant females werer stained and examined for implantation sites
Fetal examinations:: - External examinations: Yes [all per litter]
- Soft tissue examinations: Yes [all per litter]
- Skeletal examinations: Yes [all per litter]
- Head examinations: Yes [half per litter]
Statistics:: Binary response variables were compared among groups by chi-square tests for independence (Siegel, 1956). Pairwise comparisons for significant findings used either a two-tailed chi-square test or a Fisher's Exact Test (Siegel, 1956).
Analysis of variance (ANOVA) method was used to analyze continuous variable data. Response proportions were analyzed by ANOVA with an arcsin transformation of the response proportion. Orthogonal a priori comparisons were made among treatment group means for rabbits and rats. All orthogonal comparisons were two-tailed tests.
Absolute maternal organ weights were analyzed by analysis of covariance using the terminal body weight minus the weight of the gravid uterus (extragestational body weight) as the covariate. Relative organ weights were also analyzed as a percentage of the extragestational body weight by analysis of variance.
Body weights and crown-rump lengths for live male and female fetuses were analyzed by nested analysis of variance. The analysis takes into account the effects of treatment, litter, and sex an the body weight and crown-rump length measurements.
Repeated-measures data, such as maternal body weight, were analyzed by a multivariate repeated-measures analysis. Orthogonal polynomials were fit for each animal for which there were complete data, and a multivariate analysis of variance was performed an the coefficients to identify differences in growth patterns among exposure groups (Bock, 1975).
Indices:: No Formulas for calculation were presented

- percent sperm-positive females pregnant at 21 dg
- no. corpora lutea/dam
- no. implantation sites/dam
- no. resorptions/litter
- resorptions/implantation sites
- resorptions/litter
- no. dead fetuses/litter
- no. live fetuses/litter
Details on maternal toxic effects:: Maternal toxic effects:no effects

Details on maternal toxic effects:
FOOD CONSUMPTION AND BODY WEIGHT:
The lowest values for food consumption were consistently observed in animals from the group inhaling filtered air. When the two groups of n-butyl-acetate-exposed rabbits were compared, there were significant differences in food consumption after the onset of exposure. From 1 to 5 dg, values for Group 2 (exposed to filtered air at this time) were higher than those of Group 3. Once the n-butyl-acetate exposure was initiated in Group 2, food consumption was lower than that of Group 3 until the exposure was terminated on 19 dg. Body weights of the rabbits were similar in both n-butyl-acetate-exposed groups, but the filtered-air-exposed rabbits tended to have the lowest body weights throughout the experimental period, particularly from 15 through 30 dg.

ORGAN WEIGHTS AND HISTOPATHOLOGY
Weights of the lungs, kidneys, and spleens of the pregnant, filtered-air exposed rabbits were significantly lower than those of the n-butyl-acetate exposed groups. When relative organ weights (which correct for differences in body weight) were considered, these differences were not significant, although spleen weights tended to be lower in the filtered-air-exposed animals (P < 0.06).
Histopathologic studies performed an the rabbits necropsied at 30 dg did not relate any observed lesions to the n-butyl acetate exposures. A variety of lung lesions were seen, some of which are probably within the range of normal; others may be related to Pasteurella infections. Small foci of mononuclear inflammatory cells were common around alveoli, small airways and small blood vessels. A few bronchi and bronchiales contained small accumulations of heterophils and minimal to mild increases in bronchus-associated lymphoid tissue (BALT). Epithelial hyperplasia of bronchi was mild in the Group 1 rabbits and minimal in the two n-butyl-acetate-exposed groups. The changes were evenly distributed in all groups.
Renal changes, consisting of minimal to mild tubular mineralization and subacute to chronic interstitial nephritis, were evenly distributed throughout all exposure groups. Incidental findings of extramedullary hematopoiesis in the spieen appeared minimally to mildly excessive in only four animals, one of which had peritonitis.
Regressing corpora lutea corresponded well with the status of uterine sections from nonpregnant rabbits or from animals in which pregnancy was detected by uterine staining (two rabbits in Group 1). One Group 3 rabbit had such severe suppurative metritis and peritonitis that ovarian tissue could not be identified.

FERTILITY AND REPRODUCTIVE STATUS
Intrauterine mortality rate and reproductive performance were unaffected by exposure of rabbits to n-butyl acetate:
: Key result
Dose descriptor:: NOAEC
Remarks:: maternal toxicity
Effect level:: 1 500 ppm (nominal)
Basis for effect level:: other: maternal toxicity
Details on embryotoxic / teratogenic effects:: Embryotoxic / teratogenic effects:no effects

Details on embryotoxic / teratogenic effects:
FETAL MEASURES AND MORPHOLOGY
Fetal growth measures, such as body weight and crown-rump length, were similar for n-butyl-acetate and filtered-air-exposed rabbits. Placental weights and sex ratios were also similar.
No major malformations were observed in fetuses from any exposure group. There was a significantly higher incidence of misaligned sternebrae and of retinal folds among fetuses from rabbits inhaling n-butyl acetate from 1 to 19 dg (Group 3) than in those exposed to filtered air (Group 1). The presence of a clear liquid in the gallbladder, rather than bile, was a more frequent variation in Group 3 fetuses than in those of Group 1.
: Key result
Dose descriptor:: NOAEC
Remarks:: teratogenicity and development
Effect level:: 1 500 ppm (nominal)
Basis for effect level:: other: developmental toxicity
Abnormalities:: not specified
Developmental effects observed:: not specified

Reference 3

Endpoint:: developmental toxicity
Type of information:: experimental study
Adequacy of study:: key study
Study period:: year of publication: 1982
Reliability:: 1 (reliable without restriction)
Rationale for reliability incl. deficiencies:: comparable to guideline study
Reason / purpose for cross-reference:: reference to same study
Qualifier:: equivalent or similar to guideline
Guideline:: OECD Guideline 414 (Prenatal Developmental Toxicity Study)
Deviations:: yes
Remarks:: : e.g. additional exposure during pregestation period
GLP compliance:: yes
Limit test:: yes
Species:: rat
Strain:: Sprague-Dawley
Details on test animals or test system and environmental conditions:: TEST ANIMALS
- Source: Charles River, Portage facility
- Age at study initiation: 7-8 weeks
- Weight at study initiation: males: 200-225 g; females: 170-175 g
- Fasting period before study: none
- Housing: individually in stainless steel cages
- Diet: Wayne Lab-Blox, ad libitum except during the exposure periods
- Water: ad libitum except during the exposure periods
- Acclimation period: no data
- rats were exposed and housed within the chamber
Route of administration:: inhalation: vapour
Type of inhalation exposure (if applicable):: whole body
Vehicle:: unchanged (no vehicle)
Details on exposure:: GENERATION OF TEST ATMOSPHERE / CHAMBER DESCRIPTION
- Exposure apparatus: stainless steel chamber (U.S. patent # 4,216,741)
- Method of holding animals in test chamber: in stainless steel cages
- Source and rate of air: HEPA-filtered air
- Method of conditioning air: test item vapour introduced into the filtered air system
- System of generating vapours: Liquid was pumped from a liquid reservoir to the vaporizer. Nitrogen was used to replace the depleted liquid in the reservoir, to prevent formation of an explosive mixture. The vaporizer consisted of a stainless stell cylinder covered with a glass-fiber wick from which the liquid was vaporized. An 80-watt heater and a temperature-sensi element were incorporated within the cylinder and connected to a remote temperature controller. Vaporizer surface temperatures were set at about 80°C. Each cylindrical vaporizer was positioned in the fresh-air duct leading directly into ghe exposure chamber to minimize mateila loss due to condensation on duct walls. The vapour generation system was capabel of vapourizing up to 7 ml/min of liquid into 280 L/min fresh air to produce vapour concentrations as high as 9000 ppm. The system maintained the required chamber concnetrations of 1500 ppm n-butyl acetate within +/- 3% of target concentration.
- Temperature, humidity, pressure in air chamber: 23-27°C, 40-60% RH, -0.3 to -2.0 cm H2O (relative to room)
- Air flow rate: 280 L/min
- Treatment of exhaust air: Exhaust was pumped from the chamber through a flow monitor and into the building exhaust system. The exhaust from exposure rooms was diluted with the building exhaust prior to release form the building stack to produce environmenally acceptable stack concentrations.
- at the end of the exposure period the exposure chambers were flushed with fresh air for at least 2 h

TEST ATMOSPHERE
- Brief description of analytical method used: GC/FID analysis with n-nonane as internal standard
- Samples taken from breathing zone: no
Analytical verification of doses or concentrations:: yes
Details on analytical verification of doses or concentrations:: - chamber monitoring system for constant collection of fresh samples
- GC/FID analysis
- target mean daily concentration of n-butyl acetate in the exposure chambers was 1500 +/- 150 ppm
Details on mating procedure:: - Impregnation procedure: cohoused
- If cohoused:
- M/F ratio per cage: 1/2
- Length of cohabitation: for up to 8 nights
- After 8 days of unsuccessful pairing the population of females in which sperm was not detected were held without further mating or exposure until pregnancy could be readily deteced, at which time they were necropsied (9 to 10 days).
- Proof of pregnancy: sperm in vaginal smear referred to as day 1 of pregnancy
Duration of treatment / exposure:: 7 h/d, 5 d/w during the pregestation period
7 h/d on the designated gestation days
Frequency of treatment:: Exposure schedule

Days of gestation
Group pregestation 1 to 6 7 to 16 17 to 20 21
1 Filtered air Filtered air Filtered air No exposure Sacrifice
2 Filtered air Filtered air Test chemical No exposure Sacrifice
3 Filtered air Test chemical Test chemical No exposure Sacrifice
4 Test chemical Test chemical Test chemical No exposure Sacrifice

pregestation exposure period: 3 weeks
Duration of test:: 6 weeks
Dose / conc.:: 1 500 ppm (nominal)
No. of animals per sex per dose:: group 1: 37 females
group 2: 42 females
group 3: 38 females
group 4: 43 females
Control animals:: yes, sham-exposed
Details on study design:: positive control group:
- pregnant rats, which received filtered air during the premating period, were randomly assigned to the positive control group and housed in a separate room instead of further filtered air exposure
- they received a single intraperitoneal injection of the known teratogenic substance 6-aminonicotinamide on gestation day 12 (6.5 mg/kg)
Maternal examinations:: CAGE SIDE OBSERVATIONS: Yes
- Time schedule: no data, probably daily

DETAILED CLINICAL OBSERVATIONS: No

BODY WEIGHT: Yes
- Time schedule for examinations: twice per week during pregestation; on day 1, 6, 11, 16 and 21 of gestation

FOOD CONSUMPTION AND COMPOUND INTAKE (if feeding study): Yes
- Time schedule for examinations: on a weekly basis druing the pregestational exposure and over 5-day intervals during gestation

WATER CONSUMPTION AND COMPOUND INTAKE (if drinking water study): No data

POST-MORTEM EXAMINATIONS: Yes
- Sacrifice on gestation day 21
- Organs examined:
- organ weight: liver, lung, spleen, kidneys, ovaries, uteri
- organs for histopathologic investigations: ovaries, uteri, liver, lungs with trachea, spleen, kidneys and any grossly abnormal tissue; tissues from 25% of the females (a maximum of 8 per group) and any grossly abnormal tissues were processed by routine techniques (paraffin embedding, hematoxylind and eosin staining) and subjected to histopathologcal examination
- observations internal abnormalities in pregnant and nonpregnant animals were recorded (e.g. adhesions, tumors, evidence of infection)

OTHER:
- examination for the evidence of infections in at least 5 pregnant rats from group 1 and 4: screened for Mycoplasma, Corynebacterium, Sendai virus, PVM, KRV
- female rats not inseminated after 8 nights were also investigated macroscopically and histopathologically
Ovaries and uterine content:: The ovaries and uterine content was examined after termination: Yes
Examinations included:
- Gravid uterus weight: Yes
- Number of corpora lutea: Yes
- Number of implantations: Yes
- Number of early resorptions: Yes
- Number of late resorptions: Yes
- Other:
- uteri of all apparent nonpregnant females werer stained and examined for implantation sites
Fetal examinations:: - External examinations: Yes [all per litter]
- Soft tissue examinations: Yes [all per litter]
- Skeletal examinations: Yes [all per litter]
- Head examinations: Yes [half per litter]
Statistics:: Binary response variables were compared among groups by chi-square tests for independence (Siegel, 1956). Pairwise comparisons for significant findings used either a two-tailed chi-square test or a Fisher's Exact Test (Siegel, 1956).
Analysis of variance (ANOVA) method was used to analyze continuous variable data. Response proportions were analyzed by ANOVA with an arcsin transformation of the response proportion. Orthogonal a priori comparisons were made among treatment group means for rabbits and rats. All orthogonal comparisons were two-tailed tests.
Absolute maternal organ weights were analyzed by analysis of covariance using the terminal body weight minus the weight of the gravid uterus (extragestational body weight) as the covariate. Relative organ weights were also analyzed as a percentage of the extragestational body weight by analysis of variance.
Body weights and crown-rump lengths for live male and female fetuses were analyzed by nested analysis of variance. The analysis takes into account the effects of treatment, litter, and sex an the body weight and crown-rump length measurements.
Repeated-measures data, such as maternal body weight, were analyzed by a multivariate repeated-measures analysis. Orthogonal polynomials were fit for each animal for which there were complete data, and a multivariate analysis of variance was performed an the coefficients to identify differences in growth patterns among exposure groups (Bock, 1975).
Indices:: No Formulas for calculation were presented

- percent sperm-positive females pregnant at 21 dg
- no. corpora lutea/dam
- no. implantation sites/dam
- no. resorptions/litter
- resorptions/implantation sites
- resorptions/litter
- no. dead fetuses/litter
- no. live fetuses/litter
Details on maternal toxic effects:: Maternal toxic effects:yes

Details on maternal toxic effects:
FOOD CONSUMPTION AND BODY WEIGHT:
Food consumption was decreased in the group of rats exposed to n-butyl acetate during the first week of their pregestational exposure. These rats may have become conditioned to exposure during the second week since their food consumption for this period was higher than that of the three filtered-air exposed groups. Food consumption during the gestational exposure (1 to 16 dg) was higher in the control animals (Group 1) than in the n-butyl-acetate-exposed rats. Food consumption declined significantly in the period immediately following the initiation of chemical exposure (1 dg for Group 3 and 7 dg for Group 2). Values for Group 2 recovered and were higher than those of Group 3, even during the period following termination of exposure.
There was a loss of body weight in the Group 4 rats during the acclimatization period (between randomization and the initiation of pregestational exposure). This may have been a random variation since no apparent cause for this weight loss was found: food and water were readily available and there were no obvious signs of disease. By the end of the first week of exposure, body weights of these rats had recovered to the level of the other three exposure groups. By day 6 of the gestational exposure, body weights for Groups 3 and 4, which were inhaling n-butyl acetate, were lower than those of the filtered-air-exposed groups. Body weights for the rats exposed to this chemical remained lower than those of control rats until sacrifice.

ORGAN WEIGHTS AND HISTOPATHOLOGY
At sacrifice, extragestational weight depression in n-butyl-acetate-exposed. rats reflected patterns observed in body-weight comparisons. Liver weights were also lower in rats inhaling n-butyl acetate. The relative weights of lungs and kidneys of n-butyl-acetate exposed rats were higher than those of control animals, and these relative weights were highest in the rats exposed for 31 days.
Tissue lesions observed during histopathologic examinations could not be related to n-butyl acetate exposure. The only lung changes noted were small foci of mononuclear inflammatory cells in alveolar areas and around small blood vessels, and small foci of histiocytosis. These changes, observed in all groups, were considered minimal, nonspecific, and unimportant.
Liver changes, observed in all exposure groups, were apparent only as minimal mononuclear inflammatory cell populations in portal areas and minimal foci of mixed inflammatory cells scattered in the hepatic parenchyma. No changes were apparent in the spleens. Renal lesions were infrequently observed in any group; when observed, lesions were minimal to mild, except for one rat in Group 3 that had moderate hydronephrosis. Ovarien changes were limited to apparently regressing corpora lutea that correlated well with nonpregnant uteri.

FERTILITY AND REPRODUCTIVE STATUS
Mating performance, intrauterine mortality rate, and reproductive performance were unaffected by exposure of rats to n-butyl acetate:
: Key result
Dose descriptor:: LOAEC
Remarks:: maternal toxicity
Effect level:: 1 500 ppm (nominal)
Basis for effect level:: other: maternal toxicity
Details on embryotoxic / teratogenic effects:: Embryotoxic / teratogenic effects:yes

Details on embryotoxic / teratogenic effects:
FETAL MEASURES AND MORPHOLOGY
Body weights and crown-rump lengths of both male and female fetuses were lower in all n-butyl-acetate-exposed groups than in the filtered-air-exposed rats. Neither the duration of exposure to the chemical for the period of gestation at the initiation of exposure had a significant effect an fetal growth indices. Placental weight reductions also occurred in n-butyl-acetate-exposed rats. Sex ratios were unaffected.
Two fetuses in Group 2, one in Group 3, and three in Group 4 had major malformations which included: multlple facial defects, eye defects, diaphragmatic hernias, and generalized brain dysmorphology. The lesions described a "generalized brain dysmorphology", included massive distortion of the external and internal architecture of the brain; inequalities in size of the olfactory lobes, and abnormalities in shape and size of the cerebral hemispheres. Hemorrhage was apparent around exterior brain surfaces.
The incidence of rib dysmorphology was increased in fetuses of rats exposed to n-butyl acetate during gestation. The incidence of wavy, fuse and bifid ribs increased in rats exposed from 7 to 16 dg (P = 0.05), or from 1 to 16 dg (P = 0.07). Reduced pelvic ossification was also observed in fetuses of Groups 2 and 3 (P = 0.08 and P = 0.002, respectively). A larger number of fetuses with dilated ureters was noted in rats that were exposed to n-butyl acetate for 31 days than in the filtered-air-exposed animals.
: Key result
Dose descriptor:: NOAEC
Remarks:: teratogenicity
Effect level:: 1 500 ppm (nominal)
Basis for effect level:: other: no teratogenicity observed
Dose descriptor:: LOAEC
Remarks:: developmental toxicity
Effect level:: 1 500 ppm (nominal)
Basis for effect level:: other: Developmental toxicity (reduced fetal size, rib dysmorphology) in the presence of maternal toxicity was not considered as an independent effect.
Abnormalities:: not specified
Developmental effects observed:: not specified

Reference 4

Endpoint:: developmental toxicity
Type of information:: experimental study
Adequacy of study:: supporting study
Reliability:: 1 (reliable without restriction)
Rationale for reliability incl. deficiencies:: test procedure in accordance with generally accepted scientific standards and described in sufficient detail
Principles of method if other than guideline:: In a behavioural teratology study, exposed (6 wk) male rats were mated to non-exposed females. In another trial, non-exposed males and females were mated and subsequently the females were exposed. Functional and neurochemical observations were performed with the offspring (up to 90 d postnatal).
GLP compliance:: no
Species:: rat
Strain:: Sprague-Dawley
Route of administration:: inhalation
Details on exposure:: Groups of 18 male Sprague-Dawley rats were exposed to concentrations of 0, 3000, or 6000 ppm (0, 9.2 or 18.5 mg/L) nBA for 7 hours/day for 6 weeks. These males were then mated to non-exposed female rats of the same strain. In a separate experiment, groups of 15 pregnant female rats were exposed to concentrations of 0, 3000, or 6000 ppm for 7 hours/day from gestation Day 1-20. These females were then allowed to deliver.
Duration of treatment / exposure:: day 1 - 20 of gestation
Frequency of treatment:: 7 h/d
No. of animals per sex per dose:: 18 males/ 15 females
Control animals:: yes
Details on study design:: Sex: male/female
Duration of test: 20 days
Fetal examinations:: The offspring from these two groups were then observed for signs of developmental neurotoxic effects. Offspring were examined from postnatal days 10-90 for the following measures: ascent on a wire mesh screen, rotorod, open-field and photoelectrically-monitored activity, running wheel, avoidance conditioning and operant conditioning. Acetylcholine, dopamine, norepinephrine, serotonin, met-enkephalin, beta-endorphin, and Substance P. neurotransmitter levels were measured from the cerebrum, cerebellum, brainstem, and midbrain.
Details on maternal toxic effects:: No general toxicity to maternal and paternal animals was reported. No effect on pregnancy rate was found after either maternal or paternal exposure.
: Key result
Dose descriptor:: NOAEC
Remarks:: maternal toxicity
Effect level:: 18.5 mg/L air
Basis for effect level:: other: maternal toxicity
Details on embryotoxic / teratogenic effects:: There were no behavioral changes in the offspring in terms of their performance in ascent test, rotorod performance, open field performance, or operant conditioning. In offspring at 6000 ppm, the time receiving shock and the total number of times that rats crossed from one side of the cage to the other were both statistically significantly increased over controls. Monitoring of photoelectric activity showed statistically significantly lower counts in female offspring of to the 3000 ppm group but not in offspring of the high-concentration paternal exposure group. Tests for avoidance conditioning showed that male offspring of the 3000 ppm group required statistically significantly fewer trials to reach criterion than controls; no statistically significant change was observed at the high concentration. Analysis of neurotransmitter concentrations in the brains of offspring revealed statistically significant increases in the overall concentration of serotonin (mean ± SEs were 14.48 ± 2.38 versus 7.802 ± 1.48 in controls) and dopamine (0.715 ± 0.127 versus 0.515 ± 0.095 in controls) in offspring of the 6000 ppm group. There were no other statistically significant changes in neurotransmitter concentrations associated with exposure. The study authors also indicated that the changes in both the neurobehavioral tests and neurotransmitter concentrations observed in the animals exposed to butan-1-ol were within the range of control data from their laboratory or within normal biological variance. Concerning the neurotransmitter concentrations, a recent publication by A. Wojnicz et al. (Clinica Chimica Acta 453 (2016) 174–181) established a methodology for measurements of several neurotransmitters and their metabolites in rat brain sample and compared their measured mean concentrations to mean concentrations published in the literature previously. For both serotonin and dopamine at least a 3-fold difference in mean concentration in un-treated rats between lowest and highest mean published concentration is evident showing that the biological variance of normal neurotransmitter levels in the rat brain is highly variable. The changes between control and high-dose neurotransmitter mean levels observed in this study are thus within normal biological variance (a less than 2-fold change for serotonin and a less than 1.5-fold change for dopamine) and are thus not considered adverse.
Dose descriptor:: NOAEC
Remarks:: developmental neurotoxicity
Effect level:: 18.5 mg/L air
Basis for effect level:: other: developmental (neuro)toxicity
Abnormalities:: not specified
Developmental effects observed:: not specified

Reference 5

Endpoint:: developmental toxicity
Type of information:: experimental study
Adequacy of study:: key study
Reliability:: 2 (reliable with restrictions)
Rationale for reliability incl. deficiencies:: study well documented, meets generally accepted scientific principles, acceptable for assessment
Principles of method if other than guideline:: Groups of approximately 15 Sprague-Dawley rats were exposed at 8000, 6000, 3500, or 0 ppm 1-butanol, for 7 hr/day on Gestation Days 1- 19 (sperm = 0). The highest concentration was selected to produce maternal toxicity. Dams were sacrificed on Gestation Day 20, and fetuses were individually weighed, tagged, and examined for external malformations. One-half of the fetuses were stained and examined for skeletal abnormalities, and the other half were examined for visceral defects using the Wilson technique.
GLP compliance:: no
Species:: rat
Strain:: Sprague-Dawley
Details on test animals or test system and environmental conditions:: TEST ANIMALS
- Source: Charles River Breeding Laboratories
- Weight at study initiation: 176-200 g
- Housing: individually
- Diet: ad libitum (except during exposure)
- Water: ad libitum (except during exposure)
- Acclimation period: 1-2 weeks

ENVIRONMENTAL CONDITIONS
- Temperature (°C): 24 +- 2 °C
- Humidity (%): 50 +- 10 %
- Photoperiod (hrs dark / hrs light): 12/12
Route of administration:: inhalation: vapour
Type of inhalation exposure (if applicable):: whole body
Vehicle:: other: air
Details on exposure:: GENERATION OF TEST ATMOSPHERE / CHAMBER DESCRIPTION
- Exposure apparatus: The inhalation exposures were conducted in 0.5-m3 Hinners-type exposure chambers
- Method of holding animals in test chamber: Females were placed into 13 x 25 x 18-cm compartments in stainless-steel wire-mesh caging within the exposure chambers.

The vapor generation equipment was housed above the exposure chambers in glove boxes which were maintained under negative pressure to prevent any leakage of contaminants into the room. The test substance was placed into a flask. A low-flow pump circulated liquid from the reservoir flask into a 10-ml syringe contained within the flask such that the syringe was constantly overflowing.
Thus the syringe provided a constant head of chemical for a second pump (controlled by a micrometer adjustment) which injected the specified amount of liquid into a three-way valve which was attached to a Greensmith impinger. Heated compressed air was introduced through the second inlet of the three-way valve. Alcohol evaporation was controlled by regulating the preheating of compressed air. The impinger provided increased contact time between the air and the liquid to ensure total evaporation. In generation of high concentrations, glass beads were also placed at the bottom of the impinger to further increase the heat transfer area between the alcohol and the compressed air. This vapor and air mixture was introduced into the chamber airflow upstream of the orifice plate. The turbulence and pressure drop created by the orifice plate provided uniform mixing downstream of the vapor and air before the mixture entered the chamber. Airflow through the chambers provided approximately one air change per minute.

TEST ATMOSPHERE
- Brief description of analytical method used: The concentration within the chamber was monitored continuously with a Miran 1 A general-purpose infrared analyzer which was calibrated within the range to be tested.
- Samples taken from breathing zone: no data
Analytical verification of doses or concentrations:: yes
Details on analytical verification of doses or concentrations:: The concentration within the chamber was monitored continuously with a Miran 1 A general-purpose infrared analyzer which was calibrated within the range to be tested.
Details on mating procedure:: - Impregnation procedure: [cohoused]
- If cohoused:
- M/F ratio per cage: 1/1
- Length of cohabitation: until vaginal plug or sperim in vaginal smear was detected
- Verification of same strain and source of both sexes: [yes]
- Proof of pregnancy: [vaginal plug and/or sperm in vaginal smear] referred to as [day 0] of pregnancy
Duration of treatment / exposure:: day 1 - 19 of gestation
Frequency of treatment:: 7 h/d
Duration of test:: until day 20 of gestation
No. of animals per sex per dose:: 15-18 females per dose
Control animals:: yes
Details on study design:: - Dose selection rationale: The doses were selected based on the results of an initial pilot study. For the teratology phase, the high concentration was selected to be maternally toxic, but not lethal, and two lower concentrations were included.
Maternal examinations:: CAGE SIDE OBSERVATIONS: Yes
- Time schedule: not specified
- Cage side observations: not specified

DETAILED CLINICAL OBSERVATIONS: Yes
- Time schedule: not specified

BODY WEIGHT: Yes
- Time schedule for examinations: Maternal weights were measured on Gestation Days 0, 7, 14, and 20. Females were also weighed each morning for the first week of exposure.

FOOD CONSUMPTION: Yes
Weekly food intake was measured on Gestation Days 0, 7, 14, and 20.

WATER CONSUMPTION: Yes
- Time schedule for examinations: Water intake was measured on Gestation Days 0, 7, 14, and 20.

POST-MORTEM EXAMINATIONS: Yes
- Sacrifice on gestation day 20
- Organs examined: uterus with ovaries attached, no futher organs specified
Ovaries and uterine content:: The ovaries and uterine content was examined after termination: Yes
Examinations included:
- Gravid uterus weight: No data
- Number of corpora lutea: Yes
- Number of implantations: Yes
- Number of early resorptions: Yes
- Number of late resorptions: Yes
Fetal examinations:: - External examinations: Yes: [all per litter]
- Soft tissue examinations: Yes: [half per litter]
- Skeletal examinations: Yes: [half per litter]
- Head examinations: No data
Statistics:: For the maternal data, multivariate analysis (with baseline as covariate) was used for weight comparisons across groups. The group differences in food and water intake were analyzed by multivariate analysis of variance. A Kruskal-Wallis test was used for group compansons of corpora lutea per animal. For the fetal data, analysis of variance was used to compare fetal weights across groups and sex. Group comparisons of the variables including litter size, percentage alive/litter, percentage normal/litter, and percentage females/litter were made using the Kruskal-Wallis test. For the variables including skeletal malformations, skeletal variations, visceral malformations, visceral variations, external malformations, and normormal fetuses, the number of litters with one or more of the variables of interest was compared between groups using Fisher's exact test. The results of the tests were adjusted for multiple comparisons, when appropriate, using the Bonferroni technique. A probability of p <= 0.05 was required for significance.
Indices:: no data
Historical control data:: no data
Details on maternal toxic effects:: Details on maternal toxic effects:
8000 ppm produced narcosis in approximately one-half of the dams. No behavioural effects were noted at 6000 ppm. Two of eighteen dams at 8000 ppm died during the exposure period. Feed consumption was decreased in the 6000 and 8000 ppm exposed dams (the statistical significance in the 8000 ppm group disappeared when adjusted for multiple comparisons), the 3500 ppm dams were similar to controls.
For 1-butanol, food consumption was reduced both at 6000 and 8000 ppm (overall means were 382 g for controls versus 320 and 332 g respectively). Water intake increased as pregnancy progressed and was generally higher, though not significantly, in treatment groups than in controls.
: Key result
Dose descriptor:: NOAEL
Remarks:: maternal toxicity
Effect level:: 10.8 mg/L air
Based on:: test mat.
Basis for effect level:: other: maternal toxicity
Details on embryotoxic / teratogenic effects:: Details on embryotoxic / teratogenic effects:
No effect was observed on mean corpora lutea/litter, mean resorptions/litter, mean number of live foetuses/litter or sex ratio. Foetal weights were slightly decreased at 6000 and 8000 ppm groups, but the 3500 ppm group was unaffected. External foetal malformations were not observed. There were no differences in malformation rates (skeletal or visceral) or in rates of commonly observed variations. However, there was a slight increase in the percent of fetuses with any skeletal variation or malformation (mainly rudimentary cervical ribs) in the 8000 ppm group but not in the lower two exposure groups. These effects are not considered to be malformations but variations (Hofman et al., Reproductive Toxicology 61 (2016) 177–185) and thus do not adversely affect the survival or health.
: Key result
Dose descriptor:: NOAEL
Remarks:: teratogenicity
Effect level:: 24.7 mg/L air
Based on:: test mat.
Basis for effect level:: other: teratogenicity
: Key result
Dose descriptor:: NOAEL
Remarks:: developmental toxicity
Effect level:: 10.8 mg/L air
Basis for effect level:: other: fetotoxicity
Abnormalities:: not specified
Developmental effects observed:: not specified

Reference 6

Endpoint:: developmental toxicity
Type of information:: experimental study
Adequacy of study:: supporting study
Reliability:: 2 (reliable with restrictions)
Rationale for reliability incl. deficiencies:: study well documented, meets generally accepted scientific principles, acceptable for assessment
Qualifier:: equivalent or similar to guideline
Guideline:: OECD Guideline 414 (Prenatal Developmental Toxicity Study)
GLP compliance:: not specified
Limit test:: no
Species:: rat
Strain:: Sprague-Dawley
Details on test animals or test system and environmental conditions:: TEST ANIMALS
- Source: IFFA CREDO Breeding Laboratories (Saint-Germain-sur-l'Arbresle, France
- Weight at study initiation: 180-200 g (females
- Fasting period before study: no
- Housing: individually after mating
- Diet: food pellets (UAR Alimentation Villemoisson, France), ad libitum
- Water: filtered tap water, ad libitum
- Acclimation period: 2 weeks

ENVIRONMENTAL CONDITIONS
- Temperature (°C): 21 +/ 2
- Humidity (%): 50 +/- 5
- Photoperiod (hrs dark / hrs light): 12/12
Route of administration:: inhalation: vapour
Type of inhalation exposure (if applicable):: whole body
Vehicle:: unchanged (no vehicle)
Details on exposure:: GENERATION OF TEST ATMOSPHERE / CHAMBER DESCRIPTION
- Exposure apparatus: 200 l glass/stainless-steel inhalation chambers with dynamic and adjustable laminar air flow
- Method of holding animals in test chamber: cages
- Method of conditioning air: vapour generation by passing an additional airflow through the fritted disk of a heated bubbler containing test item; the vaporized test item was carried out into the main air inlet pipe of the exposur chamber
- Temperature, humidity, pressure in air chamber: 21-25°C, 30-70%, negative pressure of nomore than 3 mm water
- Air flow rate: laminar air flow (5-10 m3 h-1)

TEST ATMOSPHERE
- Brief description of analytical method used: gas chromatograph with FID
- Samples taken from breathing zone: yes
Analytical verification of doses or concentrations:: yes
Details on analytical verification of doses or concentrations:: gas chromatograph with FID
Details on mating procedure:: - Impregnation procedure: cohoused
- If cohoused:
- M/F ratio per cage: 1/2-3
- Verification of same strain and source of both sexes: yes
- Proof of pregnancy: sperm in vaginal smear referred to as day 0 of pregnancy
Duration of treatment / exposure:: 6 h/d, GD 6-20
Frequency of treatment:: daily
Duration of test:: until GD21
Dose / conc.:: 0 ppm (nominal)
Dose / conc.:: 500 ppm (nominal)
Dose / conc.:: 1 000 ppm (nominal)
Dose / conc.:: 2 000 ppm (nominal)
Dose / conc.:: 3 000 ppm (nominal)
No. of animals per sex per dose:: 19-21 pregnant females
Control animals:: yes, sham-exposed
Details on study design:: - Dose selection rationale: findings in a subchronic toxicity study and pretest
Maternal examinations:: CAGE SIDE OBSERVATIONS: Yes
- Time schedule: daily

DETAILED CLINICAL OBSERVATIONS: No data

BODY WEIGHT: Yes
- Time schedule for examinations: GD 0, 6, 13, 21

FOOD CONSUMPTION AND COMPOUND INTAKE : Yes
- Food consumption for each animal determined and mean daily diet consumption calculated as g food/animal/day: Yes

WATER CONSUMPTION AND COMPOUND INTAKE (if drinking water study): No data

POST-MORTEM EXAMINATIONS: Yes
- Sacrifice on gestation day 21
- Organs examined: uterus
Ovaries and uterine content:: The uterine content was examined after termination: Yes
Examinations included:
- Gravid uterus weight: Yes
- Number of corpora lutea: Yes
- Number of implantations: Yes
- Number of early resorptions: Yes
- Number of late resorptions: Yes
Fetal examinations:: - External examinations: Yes: all per litter
- Soft tissue examinations: Yes: half per litter
- Skeletal examinations: Yes: half per litter
- Head examinations: No data
Statistics:: - statistical evaluation performed
Indices:: none
Details on maternal toxic effects:: Maternal toxic effects:yes

Details on maternal toxic effects:
- weight gain dose dependently decreased (statistically significant at 2000 and 3000 ppm; details are presented below)
- food consumption dose dependently decreased (statistically significant at 1000 ppm or higher concentrations; details are presented below)
: Key result
Dose descriptor:: NOAEC
Remarks:: maternal toxicity
Effect level:: 500 ppm (nominal)
Basis for effect level:: other: maternal toxicity
Details on embryotoxic / teratogenic effects:: Embryotoxic / teratogenic effects:yes

Details on embryotoxic / teratogenic effects:
- dose dependently decreased fetal weigth, slightly lower than the control at 2000 ppm and significantly reduced at 3000 ppm (3% and 12-13% less than control, respectively)
- malformations were only seen in single fetuses in the 1000 and 2000 ppm group
- several common external and visceral variations were observed without any indication of a concentration-response relationship, therefore, they were not regarded to be treatment related
: Key result
Dose descriptor:: NOAEC
Remarks:: developmental toxicity
Effect level:: 2 000 ppm (nominal)
Basis for effect level:: other: dose dependently decreased fetal weight (statistically significant only at the highest exposure concentration: 3000 ppm); no teratogenicity observed
Dose descriptor:: NOAEC
Remarks:: teratogenicity
Effect level:: 3 000 ppm (nominal)
Basis for effect level:: other: no teratogenicity observed up to the highest dose tested
Abnormalities:: not specified
Developmental effects observed:: not specified

Reference 7

Endpoint:: developmental toxicity
Type of information:: experimental study
Adequacy of study:: supporting study
Reliability:: 2 (reliable with restrictions)
Rationale for reliability incl. deficiencies:: study well documented, meets generally accepted scientific principles, acceptable for assessment
Principles of method if other than guideline:: Female rats were given aqueous solutions of n-butanol containing 0.24, 0.8 and 4% n-butanol (0.3; 1.0 and 5.0 g/kg/day) for 8 weeks before and during gestation. The control animals received tap water. The experiment was performed in two stages. The first comprised of the assessment of the oestrous cycle before exposure and then during 4-5 and 7-8 weeks of exposure, and the second stage of the fertility of female rats and their foetal development.
GLP compliance:: not specified
Species:: rat
Strain:: not specified
Details on test animals or test system and environmental conditions:: TEST ANIMALS
- Source: Own breeding colony (Imp:DAK)
- Age at study initiation:10 wks (females)
- Weight at study initiation: Females: 180-200 g
- Diet: ad libitum
- Water: ad libitum
- Acclimation period: no data

ENVIRONMENTAL CONDITIONS
- Temperature (°C): ca. 22 °C
- Humidity (%): 45-55 %
- Photoperiod (hrs dark / hrs light): 12/12
Route of administration:: oral: drinking water
Vehicle:: water
Details on exposure:: PREPARATION OF DOSING SOLUTIONS:
the test substance was mixed with drinking water, the stability of the aqueous n-butyl alcohol solutions was assessed on several consecutive days
Analytical verification of doses or concentrations:: yes
Details on analytical verification of doses or concentrations:: The stability of the aqueous n-butyl alcohol solutions was assessed on several consecutive days after their preparation using a Varian Aerograph 2800 gas chromatograph equipped with FID. The column was glass (2 in x 2 mm id .) packed with Porapak Q. The operating conditions were; carrier gas flow (nitrogen) 30 cm3/min ; hydrogen 30 cm3/min ; air 300 cm3/min; the temperature of the column, injection part and detector were 200°C, 200°C, 230°C, respectively. It was determined that the aqueous n-butyl alcohol solutions were stable within the concentration range used in the experiment (0.24-4%).
Details on mating procedure:: - Impregnation procedure: [cohoused]
- If cohoused:
- M/F ratio per cage: no data
- Length of cohabitation: 3 weeks with untreated males
- Verification of same strain and source of both sexes: [yes]
- Proof of pregnancy: [sperm in vaginal smear] referred to as [day 0] of pregnancy
Duration of treatment / exposure:: Exposure period: 8 weeks premating, mating (max. 3 weeks) , gestation day 0 - 20
Frequency of treatment:: daily, continuous
Duration of test:: until day 20 of gestation
No. of animals per sex per dose:: 11-17 females per dose
Control animals:: yes
Maternal examinations:: CAGE SIDE OBSERVATIONS: Yes
- Time schedule: The general behaviour of the animals was observed throughout the experiment.

DETAILED CLINICAL OBSERVATIONS: No data

BODY WEIGHT: Yes
- Time schedule for examinations: Weight gain was monitored every week in the nonpregnant females and on days 3, 7, 10 and 17 of gestation in the pregnant animals

FOOD CONSUMPTION:
- The daily intake of food was monitored every week in the nonpregnant females and on days 3, 7, 10 and 17 of gestation in the pregnant animals.

WATER CONSUMPTION AND COMPOUND INTAKE (if drinking water study): Yes
- Time schedule for examinations: The daily intake of water or n-butanol solutions was monitored every week in the nonpregnant females and on days 3, 7, 10 and 17 of gestation in the pregnant animals.

POST-MORTEM EXAMINATIONS: No data
Ovaries and uterine content:: The ovaries and uterine content was examined after termination: Yes
Examinations included:
- Gravid uterus weight: No data
- Number of corpora lutea: Yes
- Number of implantations: Yes
- Number of early resorptions: Yes
- Number of late resorptions: Yes
Fetal examinations:: - External examinations: Yes: [all per litter]
- Soft tissue examinations: Yes: [half per litter]
- Skeletal examinations: Yes: [half per litter]
- Head examinations: No data
Statistics:: In the case of variance homogeneity, one-way variance analysis and Dunnett tests were used; in the case of heterogeneity Kruskal-Wallis variance analysis was followed by non-parametric tests. Frequency data was analyzed with a Fisher exact probability test. The consumption of food and water or n-butanol solution, and body weight gain of dams were evaluated with two-way variance analysis and Scheffe test for multiple comparison.
Indices:: No data
Historical control data:: No data
Details on maternal toxic effects:: Details on maternal toxic effects:
The general appearance and behaviour of the animals exposed to n-butyl alcohol given in drinking water during the 8 weeks, as well as body weight gain, food and liquid intake were similar to that of the control animals . There were no cases of mortality in either group.
Integral toxicity indexes observed in the female rats, such as body weight gain during gestation, food and liquid (water or butanol solutions) intake, absolute and relative organ weights, hemoglobin concentration and haematocrit values did not differ between the exposed and control groups.
: Key result
Dose descriptor:: NOAEL
Remarks:: maternal toxicity
Effect level:: 5 000 mg/kg bw/day (nominal)
Basis for effect level:: other: maternal toxicity
Details on embryotoxic / teratogenic effects:: Details on embryotoxic / teratogenic effects:
The unit of statistical analysis in this study was the individual foetus, without accounting for nested-litter effects.
At 4% (about 5000 mg/kg bw/d) the crown-rump length was decreased from a control mean of 4.0 cm to 3.8 cm. Developmental anomalies were reported in all 3 dose groups, partly without dose-response relationship. Skeletal effects were limited to wavy ribs in one foetus in the low dose group (1 % of 81 foetuses examined) and one foetus with an extra 14th rib in the high dose group (2 % of 51 foetuses examined). Delayed ossification was observed in 13, 18 and 17 foetuses in the low-, mid and high-dose groups respectively (16 % of 81 foetuses, 24 % of 75 foetuses and 33 % of 51 foetuses examined). CNS effects were limited to dilation of either the subarachnoid space or lateral and/or third ventricles of the brain or external or internal hydrocephalus. Dilated renal pelvis was only observed in the foetuses of the mid-dose group and thus there was no dose-response relationship for this observation. Dilated renal pelvis is frequently observed in animal experiments, including control animals, and is usually classified as variation (Hofman et al., Reproductive Toxicology 61 (2016) 177–185).
Of the 65 control foetuses examined for skeletal effects, none had an extra 14th or wavy rib(s) or any other skeletal malformation or variation. Ten control foetuses showed delayed ossification (15 % of 65 foetuses examined). One of the 61 control foetuses examined for visceral anomalies had dilatation of the lateral and/or third ventricles of the brain (2 % of 61 foetuses examined), while none had dilatation of the subarachnoid space or external or internal hydrocephalus.
Although the authors considered all three dose levels to have increased levels of defects when compared to controls, there was no clear increase in incidence from the low exposure concentration (0.24% butan-1-ol; 300 mg/kg/day) to the high exposure concentration (4% butan-1-ol; 5000 mg/kg/day) except for dilation of the subarachnoid space. Thus a clear dose-response relationship is lacking for most of the endpoints investigated.
The authors considered the recorded developmental effects (dilatation of the brain ventricles/spaces or renal pelvis, hydrocephalus, wavy or extra ribs) as being related to Butan-1-ol and assessed these findings as “congenital defects” (e.g. malformations) in the skeleton and CNS.
Delays in ossification and wavy ribs seem to be readily repairable via postnatal skeletal remodeling, are not mechanistically linked to malformation, and often are seen in the presence of maternal or fetal toxicity (Carney and Kimmel, Birth Defects Res B Dev Reprod Toxicol. 2007 Dec; 80(6): 473-96 and Hofman et al., Reproductive Toxicology 61 (2016) 177–185).
An extra 14th rib is also not considered to be a malformation but a variation (Hofman et al., Reproductive Toxicology 61 (2016) 177–185) and thus does not adversely affect the survival or health.
Other of these so-called “congenital defects” are listed as variations or delayed development in commonly used historical databases (see also Hofman et al., Reproductive Toxicology 61 (2016) 177–185).
Of importance, the incidence of these developmental defects in the control population was zero percent (with the exception of one of 61 foetuses with brain dilatation (2 % of fetuses examined)). The incidence of “cerebral ventricle, enlargement” was 2% on a per fetus basis and 4.4% on a per litter basis in the 1995 MARTA/MTA reference database for Sprague-Dawley rats (this is a database of common malformations/variations in control animals in studies conducted in the USA). The incidence of “renal pelvis, dilated” was 0.95% on a per fetus basis and 5.2% on a per litter basis in the same reference database. However, the “congenital defects” (e.g. malformations) reported in this paper that are termed “variations” in other established databases have to be classified based upon the incidence within the specific rat strain. The incidence of variations within the rat strain used in this study is unknown since the authors used a rat strain common only to their laboratory in Poland. The laboratory feed was also unique to their laboratory in Poland. Since the strain of rat and type and quality of diet can have a profound effect on rates or variations and malformations and since there is no historical database for these animals, the term “variation” has to be assigned with reservation. However, since these variations are common to several rat strains commonly used in the United States, the term “variation” appears appropriate. It should not be surprising that high oral doses of n-butanol that would be expected to alter normal maternal physiology would cause an increase in common variations in laboratory rodents. Thus, the developmental effects seen by the authors cannot be regarded as a selective foetotoxic effect.
Overall, the NOAEL for maternal toxicity and teratogenicity is considered to be 5000 mg/kg bw/d. A NOEL for developmental effects could not be established. Moreover, it has to be considered that the limit dose for this study type is 1000 mg/kg bw/d. Thus, effects noted clearly (e.g., 2 – 5 fold) above this limit dose should be considered as of questionable or at least of minor relevance especially as the highest dose level exceeded the oral LD50 in rats by far.
: Key result
Dose descriptor:: NOAEL
Remarks:: teratogenicity
Effect level:: 5 000 mg/kg bw/day (nominal)
Basis for effect level:: other: teratogenicity
Dose descriptor:: NOEL
Remarks:: development
Effect level:: < 300 mg/kg bw/day (nominal)
Basis for effect level:: other: development
Abnormalities:: not specified
Developmental effects observed:: not specified

Effect on developmental toxicity: via oral route

Endpoint conclusion:: adverse effect observed
Dose descriptor:: NOAEL
: 1 454 mg/kg bw/day
Study duration:: subchronic
Species:: rat
Quality of whole database:: Guideline study under GLP conditions

Effect on developmental toxicity: via inhalation route

Endpoint conclusion:: adverse effect observed
Dose descriptor:: NOAEC
: 10 800 mg/m³
Study duration:: subchronic
Species:: rat
Quality of whole database:: Scientific reliable study

Effect on developmental toxicity: via dermal route

Endpoint conclusion:: no study available

Additional information

Results from valid experimental studies showed no indication, that Butan-1-ol caused developmental toxicity/developmental neurotoxicity/teratogenicity in doses below maternal toxic doses in rats. The lack of specific developmental toxicity/developmental neurotoxicity/teratogenicity is supported by inhalation studies in rats and rabbits with the read across substance n-Butyl acetate, CAS No. 123-86-4.

Oral

The prenatal developmental toxicity of Butan-1-ol was investigated in a GLP conform study according to a Japanese TG and comparable to OECD TG 414. Each 20 pregnant Sprague-Dawley rats per dose received the test substance via the drinking water at concentrations of 0.2%, 1.0% or 5.0% (corresponding to about 316, 1454 or 5654 mg/kg/day) on gestation days (GD) 0 to 20 (Ema et al. 2005). Maternal evaluations included recording of clinical signs, body weights, and food and water intake. Dams were sacrificed on GD 20 for assessment of numbers of corpora lutea, implantation sites, resorptions, and live and dead fetuses; placental weight was also recorded. Live offspring were sexed, weighed, measured (crown-rump), and examined for external and oral malformations. Half of the fetuses were prepared for examination of internal malformations and the remainder for skeletal malformations. The litter was used as the statistical unit for analysis of the data. None of the animals in any group died. Maternal body weight gain in the group exposed to 5654 mg/kg bw/d was statistically significantly decreased during GDs 0–7 (45% of controls) and GDs 0–20 (10% less than controls). Food consumption was statistically significantly decreased compared to controls in mid- and high-dose dams (8 and 20% lower than controls, respectively) throughout pregnancy. During GDs 0–7, water consumption was statistically significantly decreased at the mid- and high-doses (9 and 38% lower than controls), and was decreased throughout gestation in the high-dose dams (28% lower than controls over GDs 0–20).

There were no statistically significant differences between exposed and control rats in placental weight or numbers of corpora lutea, implantations, pre- or post-implantation losses, resorptions, or live or dead fetuses. The sex ratio of offspring was not different among the groups. Fetal body weight was statistically significantly reduced in both male (8% lower than controls) and female (10%) offspring of dams exposed to 5654 mg/kg bw/d. Body weights were decreased in the mid- and low-dose fetuses. However, the difference from control was not statistically significant. The crown-rump length of offspring was not affected. The incidences of external, oral, and visceral malformations were not increased by treatment with butan-1-ol. At the highest dose, a statistically significant increase (20/20 versus 11/20 litters in controls) in the incidence of litters with skeletal variations (primarily short supernumerary ribs) was observed, as well as a decrease in the degree of ossification (number of forepaw proximal phalanges was 0.3 ± 0.4 versus 1.6 ± 1.3 in controls). These effects are considered to be variations (Hofman et al., Reproductive Toxicology 61 (2016) 177–185) and do not adversely affect the survival or health.

The obtained results demonstrated that butan-1-ol led to indications of developmental toxicity only at maternal toxic doses. No evidence for teratogenicity of butan-1-ol was noted , the NOAEL for teratogenicity is 5.0% (5654 mg/kg/day). Based on the significant decreases in maternal body weight gain, fetal weight and increased incidence of skeletal variations, the NOAEL for maternal toxicity and developmental toxicity is 1.0% (1454 mg/kg/day) in rats. It is noteworthy to mention that the limit dose for this study type is 1000 mg/kg bw/d. Thus, effects noted clearly (e.g., 2 – 5 fold) above this limit dose should be considered as of questionable or at least of minor relevance. Furthermore, the highest dose level exceeded the oral LD50 in rats by far.

In an explorative study to investigate the effect of Butan-1-ol on fertility and prenatal development already mentioned above under effects on fertility, female Imp:DAK rats (undefined strain of test facility’s own breeding colony, Lodz, Poland) in groups of 11 - 17 animals were exposed via the drinking water at concentrations of 0, 0.24, 0.8 and 4% (corresponding to about 0, 300, 1000 and 5000 mg/kg bw/d, Sitarek, 1994). A control group of 16 rats received plain tap water. Treatment was initiated at 10 weeks of age and continued for 8 weeks prior to mating. For 14 days prior to exposure and during weeks 4–5 and 7–8 of the premating exposure period, vaginal smears were collected daily for assessment of estrous cycle. The females were then mated to untreated males for up to 3 weeks. Gestation day (GD) 0 was defined as the day of sperm detection in vaginal smears. The females were exposed to butan-1-ol continuously through the mating and gestation periods. The unit of statistical analysis in this study was the individual foetus, without accounting for nested-litter effects.

No effects were noted for general toxicity in the form of impaired general appearance, food consumption, body weight/weight gain,absolute and relative organ weight, haemoglobin concentration, haematocrit values. Fertility and developmental parameters in the form of number and length of oestrous cycles, corpora lutea, total implants, intra-uterine mortality, foetal body weights and placental weight were not affected by Butan-1-ol exposure.

At 4% (about 5000 mg/kg bw/d) the crown-rump length was decreased from a control mean of 4.0 cm to 3.8 cm. Developmental anomalies were reported in all 3 dose groups, partly without dose-response relationship. Skeletal effects were limited to wavy ribs in one foetus in the low dose group (1 % of 81 foetuses examined) and one foetus with an extra 14th rib in the high dose group (2 % of 51 foetuses examined). Delayed ossification was observed in 13, 18 and 17 foetuses in the low-, mid and high-dose groups respectively (16 % of 81 foetuses, 24 % of 75 foetuses and 33 % of 51 foetuses examined). CNS effects were limited to dilation of either the subarachnoid space or lateral and/or third ventricles of the brain or external or internal hydrocephalus. Dilated renal pelvis was only observed in the foetuses of the mid-dose group and thus there was no dose-response relationship for this observation. Dilated renal pelvis is frequently observed in animal experiments, including control animals, and is usually classified as variation (Hofman et al., Reproductive Toxicology 61 (2016) 177–185).

Of the 65 control foetuses examined for skeletal effects, none had an extra 14th or wavy rib(s) or any other skeletal malformation or variation. Ten control foetuses showed delayed ossification (15 % of 65 foetuses examined). One of the 61 control foetuses examined for visceral anomalies had dilatation of the lateral and/or third ventricles of the brain (2 % of 61 foetuses examined), while none had dilatation of the subarachnoid space or external or internal hydrocephalus.

Although the authors considered all three dose levels to have increased levels of defects when compared to controls, there was no clear increase in incidence from the low exposure concentration (0.24% butan-1-ol; 300 mg/kg/day) to the high exposure concentration (4% butan-1-ol; 5000 mg/kg/day) except for dilation of the subarachnoid space. Thus a clear dose-response relationship is lacking for most of the endpoints investigated.

The authors considered the recorded developmental effects (dilatation of the brain ventricles/spaces or renal pelvis, hydrocephalus, wavy or extra ribs) as being related to Butan-1-ol and assessed these findings as “congenital defects” (e.g. malformations) in the skeleton and CNS.

Delays in ossification and wavy ribs seem to be readily repairable via postnatal skeletal remodeling, are not mechanistically linked to malformation, and often are seen in the presence of maternal or fetal toxicity (Carney and Kimmel, Birth Defects Res B Dev Reprod Toxicol. 2007 Dec; 80(6): 473-96 and Hofman et al., Reproductive Toxicology 61 (2016) 177–185).

An extra 14th rib is also not considered to be a malformation but a variation (Hofman et al., Reproductive Toxicology 61 (2016) 177–185) and thus does not adversely affect the survival or health.

Other of these so-called “congenital defects” are listed as variations or delayed development in commonly used historical databases (see also Hofman et al., Reproductive Toxicology 61 (2016) 177–185).

Of importance, the incidence of these developmental defects in the control population was zero percent (with the exception of one of 61 foetuses with brain dilatation (2 % of fetuses examined)). The incidence of “cerebral ventricle, enlargement” was 2% on a per fetus basis and 4.4% on a per litter basis in the 1995 MARTA/MTA reference database for Sprague-Dawley rats (this is a database of common malformations/variations in control animals in studies conducted in the USA). The incidence of “renal pelvis, dilated” was 0.95% on a per fetus basis and 5.2% on a per litter basis in the same reference database. However, the “congenital defects” (e.g. malformations) reported in this paper that are termed “variations” in other established databases have to be classified based upon the incidence within the specific rat strain. The incidence of variations within the rat strain used in this study is unknown since the authors used a rat strain common only to their laboratory in Poland. The laboratory feed was also unique to their laboratory in Poland. Since the strain of rat and type and quality of diet can have a profound effect on rates or variations and malformations and since there is no historical database for these animals, the term “variation” has to be assigned with reservation. However, since these variations are common to several rat strains commonly used in the United States, the term “variation” appears appropriate. It should not be surprising that high oral doses of n-butanol that would be expected to alter normal maternal physiology would cause an increase in common variations in laboratory rodents. Thus, the developmental effects seen by the authors cannot be regarded as a selective foetotoxic effect.

Overall, the NOAEL for maternal toxicity and teratogenicity is considered to be 5000 mg/kg bw/d. A NOEL for developmental effects could not be established. Moreover, it has to be considered that the limit dose for this study type is 1000 mg/kg bw/d. Thus, effects noted clearly (e.g., 2 – 5 fold) above this limit dose should be considered as of questionable or at least of minor relevance especially as the highest dose level exceeded the oral LD50 in rats by far.

Inhalation

Butan-1-ol was also investigated for its prenatal developmental toxicity in a scientifically valid and well document inhalation study (Nelson et al. 1989a). Groups of 15-18 female pregnant Sprague-Dawley rats were exposed to concentrations of 0, 3500, 6000 and 8000 ppm (corresponding to about 0, 10.8, 18.5 and 24.7 mg/L) butan-1-ol, for 7 h/d on GD 1 - 19 (sperm positive = day 0). Dams were sacrificed on GD 20, and fetuses were individually weighed, tagged, and examined for external malformations. One-half of the fetuses were stained and examined for skeletal abnormalities, and the other half were examined for visceral defects. Two of the 18 dams at 8000 ppm died during the exposure period. At 8000 ppm narcosis occurred in approximately half of the dams on gestation day 20. At 3500 ppm no effects were seen in the dams. Foetal weights were slightly decreased at 6000 and 8000 ppm, but unaffected at 3500 ppm. No effects were observed on the number of corpora lutea, resorptions, mean number of live foetuses or mean sex ratio. No external foetal malformations were observed and there were no differences in skeletal or visceral malformation rates, or in rates of commonly observed variations. However, there was a slight increase in the percent of fetuses with any skeletal variation or malformation (mainly rudimentary cervical ribs) in the 8000 ppm group but not in the lower two exposure groups. These effects are not considered to be malformations but variations (Hofman et al., Reproductive Toxicology 61 (2016) 177–185) and thus do not adversely affect the survival or health. Overall, the developmental toxicity of Butan-1-ol appeared to be low and did not indicate selective foetal effects as it occurred only in the presence of maternal toxicity. The NOAEL for maternal toxicity and developmental toxicity including morphological fetal alterations was 3500 ppm (10.8 mg/L).

No general toxicity to maternal and paternal animals was reported. No effect on pregnancy rate was found after either maternal or paternal exposure. There were no behavioral changes in the offspring in terms of their performance in ascent test, rotorod performance, open field performance, or operant conditioning. In offspring at 6000 ppm, the time receiving shock and the total number of times that rats crossed from one side of the cage to the other were both statistically significantly increased over controls. Monitoring of photoelectric activity showed statistically significantly lower counts in female offspring of the 3000 ppm group but not in offspring of the high-concentration paternal exposure group. Tests for avoidance conditioning showed that male offspring of the 3000 ppm group required statistically significantly fewer trials to reach criterion than controls; no statistically significant change was observed at the high concentration. Analysis of neurotransmitter concentrations in the brains of offspring revealed statistically significant increases in the overall concentration of serotonin (mean ± SEs were 14.48 ± 2.38 versus 7.802 ± 1.48 in controls) and dopamine (0.715 ± 0.127 versus 0.515 ± 0.095 in controls) in offspring of the 6000 ppm group. There were no other statistically significant changes in neurotransmitter concentrations associated with exposure. The study authors also indicated that the changes in both the neurobehavioral tests and neurotransmitter concentrations observed in the animals exposed to butan-1-ol were within the range of control data from their laboratory or within normal biological variance. Concerning the neurotransmitter concentrations, a recent publication by A. Wojnicz et al. (Clinica Chimica Acta 453 (2016) 174–181) established a methodology for measurements of several neurotransmitters and their metabolites in rat brain sample and compared their measured mean concentrations to mean concentrations published in the literature previously. For both serotonin and dopamine at least a 3-fold difference in mean concentration in un-treated rats between lowest and highest mean published concentration is evident showing that the biological variance of normal neurotransmitter levels in the rat brain is highly variable. The changes between control and high-dose neurotransmitter mean levels observed in this study are thus within normal biological variance (a less than 2-fold change for serotonin and a less than 1.5-fold change for dopamine) and are thus not considered adverse. Thus, 6000 ppm (18.5 mg/L), the highest concentration tested, was a NOAEC for parental and developmental (neuro)toxicity based on the lack of neurobehavioral effects in offspring after parental inhalation exposure.

n-Butyl acetate inhalation

The prenatal developmental toxicity of n-Butyl acetate was studied in an OECD TG 414 comparable study under GLP conditions. Maternal toxicity, reproductive performance, and developmental toxicology were evaluated in New Zealand rabbits following 7 h/d inhalation exposure to 1500 ppm (7.2 mg/L) n-Butyl acetate (30 animals/group artificially inseminated; 21 -25 animals per group pregnant at sacrifice). Three different exposure regimens were used: Group 1(control): filtered air; Group 2: test item exposure from gestation day 7 through 19; Group 3: test item exposure from gestation day 1 to 19. Unexposed males were used in artificial insemination procedure (Hackett/Battelle 1982a). Necropsies were performed on rabbits at gestation day 30. Pregnant animals were examined for toxic changes, including altered food consumption, body weight, tissue weights and histopathology. Reproductive measures included the determination of numbers of corpora lutea, implantation sites, resorptions, dead fetuses and live fetuses. Live fetuses were weighed, measured, and subjected to external, visceral and skeletal examinations to detect morphologic anomalies. Food consumption was decreased in Group 2 and 3 in the week following initiation of n-Butyl acetate exposure, but also in controls. The body weight in Groups 2 and 3 were consistently higher than in controls; organ weights and histopathology appeared normal in the n-butyl acetate exposed animals. Mating and reproductive performance and intrauterine mortality were unaffected by n-Butyl acetate exposure. Foetal growth measures (foetal body weights and crown-rump length), placental weights, and sex ratios were not affected by n-butyl acetate exposures. Fetal effects of n-Butyl acetate exposure included increased incidences of retinal folds, misaligned sternebrae, and morphologic variations of the gallbladder in litters or rabbits exposed from gestation day 1 through 19. No major malformations were observed. The authors concluded that rabbit foetuses were unaffected by n-Butyl acetate exposure as none of the effects occurred consistently in both exposure groups The effects on food consumption were not regarded to be adverse. The NOAEC for maternal and developmental toxicity in this study was 1500 ppm (7.2 mg/L).

In a further study in rats, the prenatal developmental toxicity of n-Butyl acetate was studied in an OECD TG 414 comparable study under GLP conditions. Maternal toxicity, reproductive performance, and developmental toxicology were evaluated in Sprague-Dawley rats following 7 h/d inhalation exposure to 1500 ppm (7230 mg/m3) n-Butyl acetate (37 -43 animals/group). Four different exposure regimens were used: Group 1(control): filtered air; Group 2: test item exposure from gestation day 7 through 16; Group 3: test item exposure from gestation day 1 to 16; Group 4: test item exposure for 5 days/week for 3 weeks prior to mating and daily from gestation day 1 through 16. Unexposed males were used in mating (Hackett/Battelle 1982b). Necropsies were performed on rats at gestation day 21. Pregnant animals were examined for toxic changes, including altered food consumption, body weight, tissue weights and histopathology. Reproductive measures included the determination of numbers of corpora lutea, implantation sites, resorptions, dead fetuses and live fetuses. Live fetuses were weighed, measured, and subjected to external, visceral and skeletal examinations to detect morphologic anomalies.

Food consumption, body weight and liver weight was reduced in maternal rats exposed to n-Butyl acetate. Fetal size was reduced in all n-Butyl acetate exposed litters. Increased incidences of fetal rib dysmorphology were observed in rats exposed from gestation day 7 through 16, and more numerous hydroureters in fetuses from rats exposed prior to mating and from gestation day 1 through 16. There was no evidence of teratogenic effects following exposure of rats to 1500 ppm of n-Butyl acetate. The LOAEC for maternal toxicity and developmental toxicity in this study was 1500 ppm (7.2 mg/L). However, as the developmental effects were associated with clear maternal toxicity they are not considered as an independent effect.

Prenatal developmental toxicity of n-Butyl acetate was also investigated in a scientific valid study with a slightly lower reliability in Sprague-Dawley rats (19 -21 pregnant rats/dose group), which were exposed from day 6 to 20 of gestation to concentrations of 0, 500, 1000, 2000, 3000 ppm (corresponding to 0, 2.4, 4.8, 9.6 and 14.5 mg/L) for 6 h/d (whole body, Saillenfait et al., 2007).). Under the conditions tested maternal toxicity was evident at concentrations of 1000 ppm or higher (significant decrease in body weight gain at 2000 and 3000 ppm; reduced food consumption at and above 1000 ppm). The only effects on prenatal development observed was a significant decrease in fetal weight at 3000 ppm. The NOAEC for maternal toxicity was 500 ppm (2.4 mg/L) and for developmental toxicity 2000 ppm (9.6 mg/L).

Assessment of developmental neurotoxicity:

Recently an overview on Butan-1-ol induced developmental neurotoxicity and the potential mechanisms related to these effects was published (Bale AS and Lee JS, 2016). For Butan-1-ol in total five individual paper were mentioned, which are also part of this dossier, namely McLaughlin et al., 1964, Sitarek et al., 1994, Ema et al., 2005, Nelson et al., 1989a, Nelson et al., 1989b). Based on their evaluation, the authors stated that notable signs of neurotoxicity and developmental neurotoxicity have been observed in some studies where laboratory animals (rodents) were gestationally exposed and that mechanistic data supported these observations. Based on the very thorough assessment of the aforementioned studies in this CSR (see endpoint summaries “Toxicity to reproduction” and “Neurotoxicity”, we can’t follow the authors conclusion that butan-1-ol is a neuro-toxicant or induces developmental neurotoxicity.

Overview of the key findings by Bale and Lee vs. the assessment in this CSR:

	Assessment of the effects observed in the five papers cites by Bale and Lee:
	Bale AS and Lee JS (2016)	This CSR (2017):
McLaughlin et al., 1964	Increased incidence of corneal opacity (cataracts) and nerve damage at 320 and 480 mg/kg. No hatched eggs at 640 mg/kg.	No validated or appropriate exposure route, especially not for a severe irritant that causes serious damage to eyes. An in vitro method (Hen's Egg Test Chorioallantoic Membrane (HET-CAM)) has been established to test for severe ocular irritants and as butan-1-ol causes serious damage to eyes (Eye Cat. 1, H318) the observed effects in this test (corneal opacity and nerve damage) can be clearly associated to the local irritant effects of butan-1-ol. The test is considered invalid.
Sitarek et al., 1994	Increased litter incidence of dilation of the lateral and/or third ventricle and subarachnoid space of the brain in pups gestationally exposed to 300 mg/kg-day.	Study lacks historical control data which makes the interpretation of observed effects difficult. Most of the reported“congenital defects” are listed as variations or delayed development in commonly used historical databases, lack a dose response relationship anddo not adversely affect survival or health. Thus a clear indication for developmental or developmental neurotoxicity can’t be deducted from this study.
Ema et al., 2005	No significant observations were noted in fetal brains, up to 5 g/kg-day, although developmental toxicity was noted.	Developmental effects at 5 g/kg/day were associated with clear maternal toxicity and are not considered as an independent effect. No significant or relevant observations were noted in fetal brains.
Nelson et al., 1989a	Enlarged brain ventricles observed in exposed fetuses but not significantly increased from control.	Developmental toxicity of Butan-1-ol appeared to be low and did not indicate selective foetal effects as it occurred only in the presence of maternal toxicity. No adverse or statistically significant effectswere noted in fetal brains.
Nelson et al., 1989b	No neurobehavioral effects in offspring, regardless of whether mothers or fathers exposed. Significantly higher levels of serotonin and dopamine in several brain regions (e.g. brain stem, midbrain).	No neurobehavioral effects in offspring, regardless of whether mothers or fathers exposed. The changes between control and high-dose neurotransmitter mean levels (serotonin and dopamine) observed in this study are within normal biological variance and are thus not considered adverse.
Overall interpretation of data:	Butan-1-ol induces developmental neurotoxicity	Overall (weight of evidence) there is no indication that butan-1-ol induces developmental neurotoxicity

Justification for classification or non-classification

Classification, Labelling, and Packaging Regulation (EC) No. 1272/2008

The available data are reliable and suitable for classification purposes under Regulation 1272/2008. As a result the substance is not considered to be classified for fertility, reproduction, teratogenicity or developmental toxicity (including developmental neurotoxicity) under Regulation (EC) No 1272/2008, as amended for the eighth time in Regulation (EU) No 2016/218.

Additional information

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Reproduction or further distribution of this information may be subject to copyright protection. Use of the information without obtaining the permission from the owner(s) of the respective information might violate the rights of the owner.

Dose (%)	0 (Control)	0.2	1.0	5.0
No. of rats	20	20	20	20
No. of pregnant rats	20	20	20	20
No. of dead rats	0	0	0	0
Initial body weight	245 ± 14	247 ± 13	245 ± 11	244±12
Body weight gain during pregnancy (g)^a
Days 0–7	44 ± 7	45 ± 7	40 ± 6	20 ± 28**
Days 7–14	40±6	41±5	41±7	42±10
Days 14–20	78±14	82 ± 8	84 ± 7	75 ± 11
Days 0–20	162 ± 19	168 ± 16	165 ± 15	146 ± 16**
Food consumption during pregnancy (g)^a
Days 0–7	179 ± 12	180 ± 16	164 ± 12*	138 ± 21**
Days 7–14	193 ± 14	194 ± 17	177 ± 14**	160 ± 11**
Days 14–20	176 ± 14	175 ± 15	161 ± 12**	143 ± 11**
Days 0–20	548 ± 38	548 ± 46	503 ± 34**	441 ± 34**
Water consumption during pregnancy (ml)^a
Days 0–7	284 ± 28	305 ± 37	258 ± 29*	175 ± 34**
Days 7–14	318 ± 35	337 ± 48	299 ± 40	239 ± 80**
Days 14–20	328 ± 47	342 ± 47	334 ± 46	256 ± 85**
Days 0–20	930 ± 105	983 ± 126	890 ± 106	669 ± 182**
Mean daily intakes of 1-butanol (mg/kg)^a	0	316 ± 30	1454 ± 186	5654 ± 1402

Dose (%)	0 (Control)	0.2	1.0	5.0
No. of litters	20	20	20	20
No. of litters totally resorbed	0	0	0	0
No. of corpora lutea per litter^a	16.4 ± 3.6	16.7 ± 3.0^d	16.1 ± 2.1	16.3 ± 2.6
No. of implantations per litter^a	14.3 ± 2.8	15.1 ± 1.7	15.2 ± 1.2	14.7 ± 2.5
% Preimplantation loss per litter^b	9.0	9.0d	4.4	9.2
% Postimplantation loss per litter^c	6.0	5.4	3.7	8.0
No. of live fetuses per litter^a	13.4 ± 2.6	14.3 ± 1.4	14.7 ± 1.5	13.5 ± 2.5
Sex ratio of live fetuses (male/female)	128/139	145/140	149/144	131/139
Body weight of live fetuses (g)^a
Male	4.18±0.27	4.00±0.24	4.04±0.25	3.83±0.18**
Female	3.97 ± 0.25	3.86 ± 0.20	3.83 ± 0.16	3.59 ± 0.17**
Fetal crown-rump length (mm)^a
Male	40.5 ± 1.2	40.3 ± 1.4	40.2 ± 1.2	39.7 ± 1.3
Female	39.4 ± 1.2	39.4 ± 1.2	39.3 ± 1.1	38.5 ± 1.4
Placental weight (g)
Male	0.50 ± 0.05	0.49 ± 0.05	0.48 ± 0.06	0.50 ± 0.06
Female	0.49 ± 0.05	0.48 ± 0.05	0.47 ± 0.05	0.49 ± 0.06

Dose (%)	0 (Control)	0.2	1.0	5.0
External examination
Total no. of fetuses (litters) examined	267(20)	285(20)	293(20)	270(20)
Total no. of fetuses (litters) with abnormalities	1 (1)	1 (1)	0	0
Spina bifida	1 (1)	0	0	0
Thread-like tail and anal atresia	0	1 (1)	0	0
Skeletal examination
Total no. of fetuses (litters) examined	139(20)	147(20)	152(20)	140(20)
Total no. of fetuses (litters) with abnormalities	0	0	1 (1)	0
Supernumerary of thoracic vertebral bodies and malpositioned thoracic vertebrae	0	0	1 (1)	0
Total no. of fetuses (litters) with variations	28(11)	23(12)	52(17)	69 (20)**
Bipartite ossification of thoracic centra	1 (1)	1 (1)	1 (1)	7(5)
Dumbbell ossification of thoracic centra	0	1 (1)	2(2)	3 (3)
Bipartite ossification of lumbar centra	0	0	0	2(2)
Supernumerary lumbar vertebrae	4(1)	1 (1)	5 (3)	5 (2)
Lumbarization	0	0	1 (1)	1 (1)
Bipartite ossification of sternebrae	1 (1)	1 (1)	1 (1)	1 (1)
Misaligned sternebrae	0	0	0	1 (1)
Cervical ribs	2(2)	3(3)	3 (3)	7(5)
Full supernumerary ribs	5(2)	1 (1)	10 (5)	9(5)
Short supernumerary ribs	20(10)	18 (9)	43(16)	55 (19)**
Wavy ribs	0	0	0	1 (1)
Degree of ossification^a
No. of sacral and caudal vertebrae	8.4 ± 0.5	8.4 ± 0.4	8.3 ± 0.5	8.1 ± 0.3
No. of sternebrae	5.9 ± 0.2	5.8 ± 0.2	5.8 ± 0.2	5.8 ± 0.2
No. of forepaw proximal phalanges	1.6 ± 1.3	1.6 ± 0.9	1.2 ± 1.1	0.3 ± 0.4**
Internal examination
Total no. of fetuses (litters) examined	128(20)	138(20)	141 (20)	130(20)
Total no. of fetuses (litters) with abnormalities	7(6)	9(6)	11 (8)	14(9)
Membranous ventricular septum defect	1 (1)	1 (1)	0	3 (3)
Double aorta	1(1)	0	0	0
Left umbilical artery	1 (1)	0	1 (1)	0
Thymic remnant in neck	4(4)	8 (5)	10 (8)	11 (8)

No. Rabbits	22	21	25
TIME OF MEASUREMENT
Pregestation
Week 1	220 ± 47	228 ± 40	239 ± 31	0.19	0.33
Week 2	221 ± 47	233 ± 42	245 ± 37	0.10	0.36
Gestation Days
1 to 5	189 ± 52	215 ± 29	190 ± 35	0.22	0.04*
6 to 10	175 ± 36	173 ± 40	201 ± 35	0.22	0.01*
11 to 15	148 ± 48	154± 52	185 ± 51	0.10	0.04*
16 to 20	169 ± 54	173 ± 55	207 ± 74	0.21	0.07
21 to 25	171 ± 49	190 ± 57	197 ± 75	0.16	0.70
26 to 30	142 ± 56	166± 82	156 ± 70	0.29	0.61

	Group 1	Group 2	Group 3
EXPOSURE INTERVAL
1 to 6 d	FA	FA	BA
7 to 19 d	FA	BA	BA
No. Rabbits	22	21	25
TIME OF MEASUREMENT
Randomization	4.00± 0.22	4.05± 0.35	3.96± 0.62
Gestation day
1	4.09± 0.25	4.20± 0.35	4.20± 0.33
5	4.05± 0.26	4.20± 0.34	4.14± 0.32
10	4.05± 0.25	4.14± 0.36	4.17± 0.30
15	4.05± 0.23	4.18± 0.37	4.22± 0.34
20	4.06± 0.24	4.20± 0.42	4.27± 0.40
25	4.16± 0.29	4.34± 0.45	4.39± 0.47
30	4.18± 0.30	4.34± 0.38	4.41± 0.49

Registration Dossier

Registration Dossier

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Diss Factsheets

Butan-1-ol

Endpoint summary

Administrative data

Key value for chemical safety assessment

Effects on fertility

Description of key information

Link to relevant study records

Referenceopen all close all

Reference 1

Reference 2

Reference 3

Reference 4

Effect on fertility: via oral route

Effect on fertility: via inhalation route

Effect on fertility: via dermal route

Additional information

Effects on developmental toxicity

Description of key information

Link to relevant study records

Referenceopen all close all

Reference 1

Reference 2

Reference 3

Reference 4

Reference 5

Reference 6

Body weight gain of dams

Food consumption of dams

Reference 7

Effect on developmental toxicity: via oral route

Effect on developmental toxicity: via inhalation route

Effect on developmental toxicity: via dermal route

Additional information

Justification for classification or non-classification

Additional information

Mean nominal concentrations (ppm) by generation
Target concentration (ppm):	0	750	1500	2000
F0 generation	0	749.4	1495.8	2018.1
F1generation	0	752.8	1495.5	2008.1
F2generation	0	760.8	1506.3	2009.6

EXPOSURE INTERVALL	Group 1	Group 2	Group 3
1 to 6 d	FA	FA	BA	Contrast^b
7 to 19 d	FA	BA	BA	I	II

Pregestation 1 to 6 d 7 to 16 d OBSERVATION	FA FA FA		FA FA BA		FA BA BA		BA BA BA
No. litters with live fetuses	37		42		38		43
No. fetuses examined	455		538		458		539
No. heads examined	223		267		229		272
MAJOR MALFORMATIONS
Hydrocephaly (internal)	0		0		(1/1)	2.6	8
Generalized brain dysmorphology	0		0		0		(1/1)	2.3
Cleft lip/palate Aglossia/agnathia	0 0		(1/1) (1/1)	2.4^b 2.4 ^b	0 0		0 0
Eye defects	0		0		0		(2/2)	4.6
Microphthalmia	0		0		0		(2/2)	4.6^c
Aphakia	0		0		0		(1/1)	2.3^c
Retinal disorganization	0		0		0		(1/1)	2.3^c
Diaphragmatic hernia	0		(1/1)	2.4	0		0
MINOR ANMALIES
Visceral anemalies
Lung lobe agenesis	(1/1)	2.7	0	•	0		0
Organ agenesis (unilateral)	0		(1/1)	2.4^d	0		0
Asplenia	0		(1/1)	2.4	0		0
Situs inversus totalis	0		(2/1)	2.4	0		0
Cardiovascular anomalies	0		(1/1)	2.4	(2/2)	5.3	(1/1)	2.3
Retroesophageal great vessels	0		(1/1)	2.4^e	(1/1)	_e 2.6	0
Missing innominate	0		0		(1/1)	2.6	(1/1)	2.3
Skeletal anomalies
Fused vertebra	0		(1/1)	2.4_f	(171)	2.6_f	0
Rib dysmorphology	0		(6/6)	14.3	(8/5)	13.1	(2/2)	4.7
Wavy	0		(4/4)	9.5	(4/3)	⁷.⁹	(2/2)	4.7
Fused	0		(1/1)	2.4	(4/2)	5.3	0
Bifid	0		(1/1)	2.4	(1/1)	2.6	0
Sternebral anomalies	(9/7)	18.9	(1/1)	2.4	(3/2)	5,3	(9/⁸)	18.6
Misaligned	(6/5)	13.5	(1/1)	2.4	(2/2)	5.3	(7/7)	16.2
Scrambled	(2/1)	2.7	0		0		0
Bipartite	(2/2)	5.4	(1/1)	2.4	0		(3/3)	7.0
Extra ossification site	8		0		(1/1)	2.6	(1/1)	2.3
Other anomalies
Edena	0		0	,	0		(1/1)	2.3
MORPHOLOGIC VARIATIONS
Renal variations	(3/3)	8.1	(5/5)	11.9	(5/3)	7.9	(22/10)	23.3
Hydroureter	(3/2)	5.4	(5/5)	11.9	(5/3)	7.9	(22/10)	23.3⁹
Renal pelvic cavitation	(1/1)	2.7	(2/2)	4.8	(2/1)	2.6	(5/4)	9.³
Supernumerary ribs	(4/3)	8.1	(9/4)	9.5	(4/3)	7.9	(2/2)	4.7
Extra	0		(1/1)	2.4	0		0
Ossification at luxbar 1	(4/3)	8.1	(8/4)	9.5	(4/3)	7.9	(2/2)	4.7
Reduced ossification	(389/36)	100.0	(535/42)	100.0	(452/38)	100.0	(515/43)	100.0
Skull	(9/6)	16.2	(13/11)	26.2	(16/10)	26.3	(5/5)	11.6
Vertebra	(162/33)	89.2	(253/39)	92.9	(206/36)	94.7	(238/43)	100.0
Sternebra	(381/36)	100.0	(534/42)	100.0	(449/38)	100.0	(511/43)	100.0
Ribs	(18/11)	29.2	(27/12)	28.6,	(18/10)	26.3	(34/15)	34.9
Pelvis	(7/2)	5,4	(18/9)	21.4 ^h	(33/14)	36.8^h	(3/3)	7.0
Limbs	0		0		0		(1/1)	2.3
Phalanges	(4/1)	2.7	(7/3)	7.1	(5/3)	7.9	(3/3)	7.0

		Body weight gain (g) on GD
Exposure (ppm)	No. Dams	0-6	6-13	13-21	6-21	Corrected weight gain^b
0	19	33±6^a	32±6	107±22	139±22	29±10
500	21	32±6	28±8	102±31	131±32	29±8
1000	21	35±7	26±7	102±12	128±15	24±8
2000	19	31±7	18±9^c	86±21^c	104±26^c	10±10^c
3000	21	32±8	12±7^c	74±15^c	86±18^c	-5±8^c

		Food consumption (g dam^-1day^-1) on GD
Exposure (ppm)	No. Dams	0-6	6-13	13-21	6-21
0	19	23±2^a	23±2	26±2	25±2
500	21	23±2	22±2	25±2	24±2
1000	21	23±2	21±2^b	25±2	23±2
2000	19	23±2	20±2^c	23±2^c	21±2^c
3000	21	23±3	18±2^c	20±2^c	19±1^c

		n-butanol dose (g/kg/day)
	Control	0.3	1.0	5.0
Females examined	16	17	17	11
Females inseminated	16	16	15	11
Females pregnant	12	14	12	9
Females nonpregnant	4	2	3	2
Live foetuses per litter^a	10.5 ± 3.1	11.0 ± 1.4	12.2 ± 1.9	11.3 ± 2.2
Litters with resorptions	12	9	7	9
Litters with early resorptions	10	9	7	9
Litters with late resorptions	5	2	3	2
Early resorptions per litter^a	0.8 ± 0.4	1.1 ± 1.0	1.2 ± 1.5	1.3±1.3
Late resorptions per litter^a	0.7 ± 1.2	0.1 ± 0.4	0.3 ± 0.5	0.2 ± 0.4
Corpora lutea^a	14.8 ± 2.6	14.6 ± 1.8	14.5 ± 2.1	15.1 ± 2.6
Total implants^a	12.0 ± 3.2	12.3 ± 2.1	13.6 ± 2.0	13.3 ± 2.3
Preimplantation losses^a	2.8 ± 2.1	2.4 ± 0.9	1.5 ± 1.6	2.0 ± 1.9
Postimplantation losses^a	1.5 ± 1.2	1.3 ± 1.3	1.4 ± 1.8	2.0 ± 1.6
Mean daily food intake^b(g)	21.2 ± 5.4	19.4 ± 4.6	19.4 ± 3.4	18.8 ± 1.5
Mean daily water intake^bffrdddfMKMM(m(ml)	30.3 ± 7.9	30.5 ± 6.9	35.1 ± 9.3	27.7 ± 4.2
Body weight gain of dams^a(g)	89.6 ± 18.9	90.0 ± 18.5	94.3 ± 16.9	93.9 ± 12.7
Foetal body weight^c(g)	3.2 ± 0.2	3.2 ± 0.3	3.2 ± 0.2	3.2 ± 0.3
Foetal crown-rump length^c(cm)	4.0 ± 0.1	3.9 ± 0.1	3.9 ± 0.1	3.8 ± 0.1^°
Weight of placenta^c(g)	0.55 ± 0.07	0.48 ± 0.07	0.53 ± 0.05	0.6 0 ± 0.13

	n-butanol dose (g/kg bw/day)
	Control	0.3	1.0	5.0
	Visceral observations
No. of fetuses (litters) examined	126 (12)	154 (14)	146 (12)	102 (9)
No. of fetuses (litters) examined	61 (12)	73 (14)	71 (12)	51 (9)
Percentages of fetuses (litters) with dilations of:	2 (8)	25^a(64)^a	32^a(83)^a	41^a(100)^a
- Subarachnoid space	0	3 (14)^a	10^a(25)^a	20^a(78)^a
- Lateral ventricle and/or third ventricle of the brain	2 (8)	23^a(57)^a	17^a(67)^a	25^a(78)^a
- Unilateral renal pelvis	0	0	7^a(42)^a	0
- Bilateral renal pelvis	0	0	4 (25)^a	0
Percentages of fetuses (litters) with congenital defects:	0	0	7^a(33)^a	4 (22)^a
- External hydrocephalus	0	0	3^a(17)^a	0
- Internal hydrocephalus	0	0	7^a(25)^a	4 (22)^a
	Skeletal observations
No. of fetuses (litters) examined:	65 (12)	81 (14)	75 (12)	51 (9)
Percentage of fetuses (litters) with delayed ossification:	15(67)	16 (50)	24 (58)	33^a(67)
Percentage of fetuses (litters) with congenital defect:	0	1 (7)^a	0	2 (11)^a
- 14^thrib (L1)	0	0	0	2 (11)^a
- Wavy ribs	0	1 (7)^a	0	0

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Butan-1-ol

Endpoint summary

Administrative data

Key value for chemical safety assessment

Effects on fertility

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Effect on fertility: via oral route

Effect on fertility: via inhalation route

Effect on fertility: via dermal route

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Effects on developmental toxicity

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Body weight gain of dams

Food consumption of dams

Effect on developmental toxicity: via oral route

Effect on developmental toxicity: via inhalation route

Effect on developmental toxicity: via dermal route

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Justification for classification or non-classification

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