Butan-1-ol

Endpoint summary

Description of key information

oral 

rat, 90 d: NOEL = 125 mg/kg bw (US EPA 1986; RL 1)

dermal

rabbit, 12 times in 21 days for 5 h, occlusive: drying of the skin, no systemic toxicity observed (Omie et al. 1949; RL 2)

inhalation

rat, 3 months (5 d/week, 5 h/d), vapour: Observed effect level = 320 mg/m^3, study not suitbale for NOAEL/LOAEL determination (Jajte et al. 2003; RL 2)

n-Butyl acetate inhalation

rat, 90 d, vapour: NOEL local/systemic = 2.35 mg/L, corresponding to 500 ppm, based on reduced body weight, transient CNS effects and necropsy in the olfactory epithelium (OPP/CMA 94030517 1996, RL 1)

rat, 90 d, vapour: NOEL systemic = 2.35 mg/L, corresponding to 500 ppm, based on reduced body weight (OPP/CMA 297761P 1996, RL 1)

The reported NOAELs of 500 ppm correspond to ca. 1.5 mg/L butan-1-ol.

Key value for chemical safety assessment

Repeated dose toxicity: via oral route - systemic effects

Link to relevant study records

Reference

Endpoint:

sub-chronic toxicity: oral

Type of information:

experimental study

Adequacy of study:

key study

Study period:

1985-08-19 to 1985-11-26

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

comparable to guideline 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/kg bw/d for either 6 or 13 weeks.

GLP compliance:

yes

Limit test:

no

Specific details on test material used for the study:

- lot: 3597

Species:

rat

Strain:

Sprague-Dawley

Sex:

male/female

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Source: Charles River Breeding Laboratories, Inc., Portage, Michigan, U.S.A.
- Age at study initiation: 36-37 d
- Mean weight at study initiation: males 90 g, females 86 g
- Housing: individually
- Diet: ad libitum, Purina Certified Rodent Laboratory Chow #5002 (pellet)
- Water: ad libitum, filtered municipal water
- Acclimation period: 7 days before the pretreatment week

ENVIRONMENTAL CONDITIONS
- Temperature (°C): 21 +/- 1
- Humidity (%): 47.6 +/- 9.2
- Photoperiod (hrs dark / hrs light): 12/12

Route of administration:

oral: gavage

Vehicle:

water

Details on oral exposure:

PREPARATION OF DOSING SOLUTIONS:
Dosing solutions of butanol in deionized water were used.

VEHICLE
- Concentration in vehicle: not specified
- Amount of vehicle: 10 mL/kg bw was the constant dosing volume

Analytical verification of doses or concentrations:

yes

Details on analytical verification of doses or concentrations:

GC-FI

Duration of treatment / exposure:

6 weeks (42/43 days) for animals used for interim sacrifice or 13 weeks (91/92 days) for complete study

Frequency of treatment:

daily

Dose / conc.:

30 mg/kg bw/day (nominal)

Dose / conc.:

125 mg/kg bw/day (nominal)

Dose / conc.:

500 mg/kg bw/day (nominal)

No. of animals per sex per dose:

30 (further 10 were sacrificed prior to dosing for determination of clinicopathological baseline levels)

Control animals:

yes, concurrent vehicle

Positive control:

no data

Observations and examinations performed and frequency:

CAGE SIDE OBSERVATIONS: Yes
- Time schedule: twice daily

DETAILED CLINICAL OBSERVATIONS: Yes
- Time schedule: twice daily

BODY WEIGHT: Yes
- Time schedule for examinations: Body weights were recorded weekly


FOOD CONSUMPTION: Yes
-Time schedule: Food consumption was recorded weekly


OPHTHALMOSCOPIC EXAMINATION: Yes
- Time schedule for examinations: Ophthalmic examination was conducted prior to treatment and during week 13 before final necropsy.
- Dose groups that were examined: all rats


HAEMATOLOGY: Yes
- Time schedule for collection of blood: before the start of the study (only baseline group animals), during week 6 (only interim sacrifice animals) and during week 13 (final sacrifice animals)
- Anaesthetic used for blood collection: Yes, CO2
- Animals fasted: No data
- How many animals: 10 males and 10 females/ treatment group
- parameters: hemoglobin ( HGB), hematocrit (PCV), erythrocyte count (RBC), mean cell volume (MCV), mean cell hemoglobin (MCH),mean cell hemoglobin concentration (MCHC) total and differential leucocyte counts (WBC), estimated platelet count (PLT)


CLINICAL CHEMISTRY: Yes
- Time schedule for collection of blood: before the start of the study (only baseline group animals), during week 6 (only interim sacrifice animals) and during week 13 (final sacrifice animals)
- Animals fasted: No data
- How many animals: 10 males and 10 females/ treatment group
- parameters: alkaline phosphatase (Alk phos) blood urea nitrogen (BUN), glutamate pyruvate transaminase (SGPT), glutamate oxalacetate transaminase (SGOT), glucose (Gluc), total protein (TP), albumin (Alb), A/G ratio (calculated), globulin (calculated), total bilirubin (Tot. bili.), sodium (Na), potassium (K ), chloride (Cl), calcium (Ca), inorganic phosphate (Phos), carbon dioxide (TCO2), total serum cholesterol (Chol), creatinine.


URINALYSIS: Yes
- Time schedule for collection of urine: before the start of the study, during week 6 and during week 13
- Metabolism cages used for collection of urine: yes, for 4 h
- Animals fasted: No data
- parameters: pH, specfic gravity, glucose, protein, ketones, bilirubin, urobilinogen, microscopy of sediment


NEUROBEHAVIOURAL EXAMINATION: No data

Sacrifice and pathology:

GROSS PATHOLOGY: Yes: Ten male and ten female rats from each group were necropsied on study days 43 to 44 and the remaining animals on study days 92 to 93. Gross pathology of all animals was assessed and organs from animals necropsied on study days 92 to 93 were weighed.
HISTOPATHOLOGY: Yes: A complete histopathological investigation was made of all animals of the control and high-dose groups. In the low and mid-dose groups, histopathology included the liver, kidney, and heart from all animals and all gross lesions. All animals found dead or killed in extremis were also microscopically examined.
Tissues examined in control and high dose groups: Heart and attached aorta, thymus, lungs, trachea, esophagus, stomach, salivary glands (mandibular and sublingual glands), small intestine, jejunum, ileum, colon, liver, pancreas, spleen, lymph nodes (mesenteric), kidneys, urinary bladder, adrenal glands, pituitary gland, eyes with optic nerve, thyroid and parathyroid glands, lumbar spinal cord, brain, bone marrow (femur), testes with epididymides, ovaries, uterus, cervix, skin, mammary gland, skeletal muscle, sciatic nerve, tissue masses and all other gross lesions

Statistics:

Body weight, food consumption, clinicopathologic and organ weight data were tested for homogeneity of variance by Bartlett’s method. If data was homogeneous, differences between control and treatment means were tested for statistical significance by the method of Dunnett. If data was not homogeneous, the method of Gill (modified Dunnett’s) was used.

Clinical signs:

effects observed, treatment-related

Description (incidence and severity):

Ataxia and hypoactivity (lasting less than 1 h) were observed 2 to 3 minutes after dosing in both sexes of the high-dose group (500 mg/kg bw/d) during the final 6 weeks of dosing. Such ataxia and hypoactivity are typically seen following high oral doses of alcohols. The rapid induction/remission of these effects and the reported increased incidence after the interim kill may be due to the fact that personnel were able to collect post-dose observations more quickly since fewer animals required dosing.

Mortality:

mortality observed, non-treatment-related

Description (incidence):

No significant changes between treated groups and controls were observed concerning mortality.
One mid-dose male rat died during week 1.
Three rats were found dead or sacrificed in extremis. These deaths could not be attributed to the test article but were related to treatment accidents.

Body weight and weight changes:

no effects observed

Description (incidence and severity):

No test substance related changes between treated groups and controls were observed.

Food consumption and compound intake (if feeding study):

no effects observed

Description (incidence and severity):

No test substance related changes between treated groups and controls were observed.

Food efficiency:

not examined

Water consumption and compound intake (if drinking water study):

not examined

Ophthalmological findings:

effects observed, non-treatment-related

Description (incidence and severity):

Chorioretinal hypoplasia was seen in 1 control and low-dose rat and in 3 mid and high-dose rats. This observation is commonly seen in rats of the corresponding age and not test substance related. One other unspecified lesion in one low-dose and one mid-dose rat and 2 in high-dose rats was observed. Those lesions were also considered non treatment related.

Haematological findings:

effects observed, non-treatment-related

Description (incidence and severity):

At the interim clinical pathological evaluation, red blood cell count (RBC) packed cell volume (PCV), and hemoglobin (HGB) averages of the 500 mg/kg/day dose group females were 5 % below control averages. Although these differences were statistically significant, they were small and no differences between the parameters were observed in the males of the interim evaluation or between control and treated groups of either sex at the final evaluation. Therefore, even if the lower red blood cell parameters in the 500 mg/kg/day females were an actual treatment-related effect, it was small and transitory and thus not considered as adverse.
In addition a higher (p ≤ 0.05) absolute neutrophil count in middle-dose males at interim evaluation, higher (p ≤ 0.05) relative lymphocyte count in low-dose females at final evaluation and a higher urine pH (p ≤ 0.05) in low-dose males (interim) and females (final) were detected. All those effects were statistically significant but small, occurred in one sex and at one time point only without a dose response relationship. Therefore those effects were not considered treatment related.

Clinical biochemistry findings:

effects observed, non-treatment-related

Description (incidence and severity):

A lower (p ≤ 0.05) cholesterol average in the high-dose males at interim evaluation was detected. The effect was only observed in one sex at one time point, therefore it was considered not treatment related.

Urinalysis findings:

no effects observed

Description (incidence and severity):

No significant changes between treated groups and controls were observed.

Behaviour (functional findings):

not examined

Immunological findings:

not examined

Organ weight findings including organ / body weight ratios:

effects observed, non-treatment-related

Description (incidence and severity):

Only in thyroid weight of high-dose males a slight increase was detected. No dose response relationship was observed and the difference was considered to be a chance occurrence and not treatment related.

Gross pathological findings:

no effects observed

Description (incidence and severity):

No treatment related lesions were detected. All observed lesions were either in the normal range for the test animal species and age with no differences between control and treated animals or were caused by accidents during treatment.

Neuropathological findings:

not examined

Histopathological findings: non-neoplastic:

no effects observed

Description (incidence and severity):

No treatment related lesions were detected. All observed lesions were in the normal range for the test animal species and age with no differences between control and treated animals.

Histopathological findings: neoplastic:

not examined

Other effects:

not examined

Key result

Dose descriptor:

NOEL

Effect level:

125 mg/kg bw/day (nominal)

Based on:

test mat.

Sex:

male/female

Basis for effect level:

other: no effects observed

Key result

Dose descriptor:

LOEL

Effect level:

500 mg/kg bw/day (nominal)

Based on:

test mat.

Sex:

male/female

Basis for effect level:

other: transient clinical signs of CNS depression (ataxia and hypoactivity)

Key result

Critical effects observed:

yes

Lowest effective dose / conc.:

500 mg/kg bw/day (nominal)

System:

central nervous system

Organ:

other: Not centered on a specific organ but general effects on neurological and behavioral functions as typically observed for alcohols (drowsiness and dizziness).

Treatment related:

yes

Dose response relationship:

yes

Relevant for humans:

yes

Endpoint conclusion

Endpoint conclusion:

no adverse effect observed

Dose descriptor:

NOAEL

125 mg/kg bw/day

Study duration:

subchronic

Species:

rat

Quality of whole database:

The data was considered sufficiently reliable. 125 mg/kg is actually a NOEL!

System:

central nervous system

Organ:

other: Not centered on a specific organ but general effects on neurological and behavioral functions as typically observed for alcohols.

Repeated dose toxicity: inhalation - systemic effects

Link to relevant study records

Reference

Endpoint:

sub-chronic toxicity: inhalation

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:

EPA OTS 798.2450 (90-Day Inhalation Toxicity)

Deviations:

yes

Remarks:

tissues from central and peripheral nervous system were not examined histologically

GLP compliance:

yes

Limit test:

no

Specific details on test material used for the study:

- Analytical purity determined by GC

Species:

rat

Strain:

Sprague-Dawley

Remarks:

CRL:CD(SD)BR/VAF Plus

Details on species / strain selection:

Rats were chosen as common representative species for the study.

Sex:

male/female

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Source: Charles River Kingston, USA
- Females nulliparous and non-pregnant: yes
- Age at study initiation: ca. 60 d
- Mean weight at study initiation: 271+/-7 g (males); 215+/-8 g (females); the variability in body weight of individual animals in the selected population did not exceed 20 % of the mean for each sex
- Fasting period before study: no, food and water were not available during study
- Housing: Animals were housed in an Association for the Assessment and Accreditation of Laboratory Animal Care International-accredited vivarium; non-exposure period: individually in stainless-steel, wire-mesh cagesbin room seperated from exposure room
- Diet: Certified Rodent Diet (Agway Prolab RMH 3200 ground chow), ad libitum; not available during exposure
- Water: filtered municipal tap water from Monroe County (NY) water authority, ad libitum; not available during exposure
- Acclimation period: 12 days

DETAILS OF FOOD AND WATER QUALITY:
No known contaminants which would interfere with the outcome of this study were present in the feed. There have been no contaminants identified in previous water analyses that would be expected to interfere with the conduct of the study. Food analyses and semiannual analyses of water are maintained on file within the testing laboratory.

ENVIRONMENTAL CONDITIONS
- Temperature (°F): 67-75
- Humidity (%): 46-60
- Photoperiod (hrs dark / hrs light): 12/12

Route of administration:

inhalation: vapour

Type of inhalation exposure:

whole body

Vehicle:

air

Details on inhalation exposure:

GENERATION OF TEST ATMOSPHERE / CHAMBER DESCRIPTION
- Exposure apparatus: 4200 L stainless-steel and glass NYU-type inhalation chambers (Hinners or Laskin chamber)
- Source and rate of air: filtered, compressed air
- Method of conditioning air: The test atmosphere was generated by metering the test substance into glass distillation columns packed with glass beads; for the 1500 and 3000 ppm chambers, two serial distillation columns were used whereas only one column was used for the 500 ppm concentration. Filtered, compressed air was passed through the glass bead-packed columns to evaporate the test substance. The test substance delivery rate and air flow rate were adjusted to produce the desired. The distillation columns were heated to ~ 50 °C to enhance vaporization.
- Temperature, humidity, pressure in air chamber: The temperature and humidity were maintained at 20.6–24.7 °C and 36.7–68.7 % under negative pressure.
- Air change rate: 12–14 air changes per h
- Method of particle size determination: Micro Laser Particle Counter (model /xLPC-301, Particle Measuring Systems, Inc., Boulder, CO)
- Other:
The oxygen content of the chamber exposure atmosphere was at least 19.0 %.

TEST ATMOSPHERE
- Brief description of analytical method used: Chamber vapor concentrations were monitored with a multipositional air sampling and analysis system. The system consisted of a single MIRAN® IA infrared gas analyzer (Wilks Foxboro Analytical, South Norwalk, CT) and a computer-operated four-port sampling valve (Valco Instruments, Houston, TX). Each chamber was sampled at least once per hour.
- Samples taken from breathing zone: not specified


The animals were individually housed in the chamber, and their location within the chamber was moved periodically according to a defined rotation scheme to eliminate any effect due to placement in the chamber.

Analytical verification of doses or concentrations:

yes

Details on analytical verification of doses or concentrations:

Chamber vapor concentrations were monitored with a multipositional air sampling and analysis system at least once each hour with an infrared gas analyzer set at a wavelength of 3.38 µm.
The nominal concentration was calculated by dividing the amount of test substance consumed from the reservoir (determined gravimetrically) by the total chamber air flow.

Duration of treatment / exposure:

6 h/day

Frequency of treatment:

5 days per week (Monday to Friday) for 13 consecutive weeks (65 days), surviving animals were exposed for 1 (male) or 2 (females) days in week 14.

Dose / conc.:

500 ppm

Dose / conc.:

1 500 ppm

Dose / conc.:

3 000 ppm

No. of animals per sex per dose:

15

Control animals:

yes, concurrent vehicle

Details on study design:

- Dose selection rationale:
The exposure concentrations were based on data from a two-week inhalation probe study of male rats exposed to 0, 750, 1500, or 3000 ppm of the test substance for two weeks. This study demonstrated that the test substance produced concentration-related reductions in general activity levels during exposure periods. Animals appeared to acclimate to the 750 and 1500 ppm concentrations but not to 3000 ppm. Mean body weights for the female 1500 ppm animals and for the 3000 ppm male and female animals were lower than the control group on Days 7 and 14, but no statistically significant differences were noted. Based on these results, 3000 ppm was selected as an exposure concentration that would produce overt signs of toxicity and 500 ppm was selected as an exposure concentration that was expected to have no effect. An exposure concentration of 1500 ppm was selected as the intermediate exposure concentration.
For 500 ppm the target analytical concentration was increased to 550 ppm due to varying concentrations at different places in the chamber, so that the actual exposure to the animals would be closer to 500 ppm.

Positive control:

Not conducted.

Observations and examinations performed and frequency:

CAGE SIDE OBSERVATIONS: Yes
- Time schedule: once a day on weekends
- Cage side observations included, but were not limited to, examination of the hair, skin, eyes and mucous membranes, motor activity, feces, urine, respiratory system, circulatory system, autonomic nervous system, central nervous system, and behavior patterns. Tapping on chamber to assess animals response was done.

DETAILED CLINICAL OBSERVATIONS: Yes
- Time schedule: before and after exposure (during handling)

BODY WEIGHT: Yes
- Time schedule for examinations: weekly prior to exposure; fasted body weights were measured after exsanguination but prior to necropsy

FOOD CONSUMPTION AND COMPOUND INTAKE:
Food consumption was measured weekly prior to exposure, on Day 7, 14 and weekly afterwards.
- Food consumption for each animal determined and mean daily diet consumption calculated as g food/animal/day: Yes
- Compound intake calculated as time-weighted averages from the consumption and body weight gain data: Not specified

FOOD EFFICIENCY:
- Body weight gain in kg/food consumption in kg per unit time X 100 calculated as time-weighted averages from the consumption and body weight gain data: No

OPHTHALMOSCOPIC EXAMINATION: Yes
- Time schedule for examinations: prior to the start of the study; last week of exposure
- Dose groups that were examined: before study all animals; last exposure week from control and high-concentration group (No changes were detected in the eyes of the high-concentration animals and therefore the animals from the low- and mid-concentration were not examined.)

HAEMATOLOGY: Yes
- Time schedule for collection of blood: day 30, day after last exposure
- Anaesthetic used for blood collection: Yes, Metofane
- Animals fasted: Yes
- How many animals: day 30: 5 male and 5 female of each group, after last exposure: all remaining animals
- Whole blood samples were analyzed for red blood cell count, total white blood cell counts, hemoglobin, hematocrit and red blood cell. Prothrombin time was measured. Slides with blood smears were stained and examined for cellular morphology, differential white blood cell count and platelet count.

CLINICAL CHEMISTRY: Yes
- Time schedule for collection of blood: day 30, day after last exposure
- Animals fasted: Yes
- How many animals: day 30: 5 male and 5 female of each group, after last exposure: all remaining animals
- Serum samples were analyzed for total protein, total bilirubin, calcium, phosphorous, urea nitrogen, creatinine, glucose, gamma-glutamyltransferase, aspartate aminotransferase, alanine aminotransferase, sorbitol dehydrogenase and alkaline phosphatase. Albumin concentration and isozyme profile were determined. The albumin/globulin ratio was calculated from total protein and albumin concentrations. Serum sodium, chloride and potassium concentrations were measured.

URINALYSIS: Yes.
Urine was assessed as part of the cage side observations but parameters and methods of analysis were not further specified.

NEUROBEHAVIOURAL EXAMINATION: Yes
Neurobehavioural examinations were assessed as part of the cage side observations but parameters and methods of analysis were not further specified.

IMMUNOLOGY: No

Sacrifice and pathology:

GROSS PATHOLOGY: GROSS PATHOLOGY: Yes.
- Collected tissues are listed in table 1
- Wet weights of the liver, kidneys, testes or ovaries, spleen, adrenal glands, lungs and brain were recorded for all animals at necropsy. Paired organs were weighed together, except for the testes, which were weighed individually.

HISTOPATHOLOGY: Yes
- H&E stained tissues are indicated in table 1.
- All those tissues were examined microscopically from the control and high-concentration groups. In addition, the lungs, nasal passages, thymus (males only), stomach (females only), and gross lesions were examined from the mid-and low-concentration groups.

Other examinations:

The left testis and left epididymis of each male rat were placed into individual bags and frozen at - 25 °C. The right testis was preserved in 10 % buffered formalin. Both frozen and preserved samples of testes and epididymis were submitted to Research Triangle Institute, Research Triangle Park, NC for sectioning and evaluation of sperm morphology and development. The results are expressed per gram tissue weight.

Statistics:

Mean values were calculated for analytical concentration, chamber temperature, chamber relative humidity, body weight, feed consumption, serum chemistry, hematology, and organ weights. Body weight, feed consumption, serum chemistry, hematology, organ weight and sperm count data were evaluated using the following statistical tests: Bartlett’s test (P<=0.01), one-way analysis of variance (ANOVA) (P<=0.05), and Duncan’s multiple range test (P<=0.05) or Dunnett’s test to indicate statistical significance. If the Bartlett’s test indicated unequal variances, the data were evaluated using the Kruskal–Wallis H-test and the Mann–Whitney U-test. A probability of P<=0.05 (two-tailed) was used to determine significance. If the Bartlett’s test indicated unequal variances, the data were evaluated using the Kruskal–Wallis H-test and the Mann–Whitney U-test.

Clinical signs:

effects observed, treatment-related

Description (incidence and severity):

3000 ppm: reduced activity levels (less movement, decreased alertness, and slower response) of generally minor severity during exposure, sialorrhea in 3 animals for no more than 1-2 exposure days, red discoloration of the chin hair in several females for no more than 1-2 exposure days
1500 ppm: normal for 5 h on day 0, normal for 1-2 h on day 1 and 2, afterwards reduced activity of generally minimal severity for the remainder of the daily exposure periods and all following exposures. Reduced activity of minimal severity was generally seen throughout daily exposures thereafter.
500 ppm: no observed effects

Mortality:

no mortality observed

Description (incidence):

No spontaneous mortality occurred during the study.

Body weight and weight changes:

effects observed, treatment-related

Description (incidence and severity):

- 3000 ppm: body weight significantly lower (P≤0.05) than control starting from day 7 (males) and 14 (females), weight gain were 62 % (male) and 78 % (female) of control group weight gain, body weight gain significantly lower (P≤0.05) than control (males: week 1, 2, 5-7; females: week 2, 4, 6)
- 1500 ppm: body weight significantly lower (P≤0.05) than control starting from day 42 (males) and 14 (females), weight gain were 77 % (male) and 70 % (female) of control group weight gain, body weight gain significantly lower (P≤0.05) than control (males: week 11; females: week 2)
- 500 ppm: not significantly different than control, weight gain were 90 % (male) and 107 % (female) of control group weight gain

Food consumption and compound intake (if feeding study):

effects observed, treatment-related

Description (incidence and severity):

- 3000 ppm: food consumption significantly lower (P≤0.05) than control during whole time for males and except day 84 and 91 for females, mean weekly feed consumption was 14-25 % (males) and 6-16 % (females) lower than the control group
- 1500 ppm: food consumption significantly lower (P≤0.05) than control (males: day 7, 35, 42, 49 56, 63, 70, 77, 84; females: all except day 91); mean weekly feed consumption was 4-17 % (males) and 10-15 % (females) lower than the control group
- 500 ppm: food consumption significantly lower (P≤0.05) than control (males: day 35, 42, 63, 70; females: day 7, 14); mean weekly feed consumption was 3-12 % lower for males and between 2 % higher and 7 % lower for females than the control group

Food efficiency:

not examined

Water consumption and compound intake (if drinking water study):

not examined

Ophthalmological findings:

no effects observed

Description (incidence and severity):

No changes were detected in the eyes of the high-concentration animals, therefore the animals from the low- and mid-concentration groups were not re-examined.

Haematological findings:

no effects observed

Description (incidence and severity):

hematologic parameters after 30 days :
No significant differences in hematologic parameters were seen after 30 days in all groups.
hematologic parameters after 90 days:
- 3000 ppm: significantly higher mean erythrocyte counts, hemoglobin concentration and hematocrit values after 90 days compared to control, mean eosinophil percentage (male only) was significantly higher
- 1500 ppm: no effects observed
- 500 ppm: no effects observed

blood cell morphology after 30 days
Spherocytosis and poikilocytosis were seen in blood smears of animals from most groups.
- 3000 ppm: polychromasia in 2 females, Howell-Jolly bodies in blood and anisocytosis in 1 female
- 0 ppm (control): polychromasia in 1 male
blood cell morphology after 90 days
Poikilocytosis was seen in blood smears of animals from groups.
- 1500 ppm: microcytosis in 1 male, anisocytosis
- 500 ppm: microcytosis in 1 male, spherocytosis in 2 males, anisocytosis
- 0 ppm (control): anisocytosis

All the values were within normal limits for rats of this age and for the age and strain of the animals used, therefore none of the differences were considered biologically significant.

Clinical biochemistry findings:

effects observed, treatment-related

Description (incidence and severity):

The observed changes were not considered to be toxicologically meaningful.
3000 ppm: significantly lower (approx. 1 Meq/L) mean sodium concentrations after 30 days, significantly lower mean albumin and total protein concentrations in females after 90 days
1500 ppm: significantly lower (< 4 Meq/L) mean chloride concentrations after 30 days, significantly higher mean sorbitol dehydrogenase activity in males after 90 days
500 ppm: no effects observed

Urinalysis findings:

not specified

Behaviour (functional findings):

not specified

Description (incidence and severity):

No effects were described besides those observed as clinical signs.

Immunological findings:

not examined

Organ weight findings including organ / body weight ratios:

effects observed, treatment-related

Description (incidence and severity):

3000 ppm: absolute liver, kidney, brain (male only) and spleen weights significantly lower than control; relative organ weights only significantly lower for spleen (male only); significantly higher relative brain, lungs and testes weight in males and adrenal gland weight for males and females
1500 ppm: absolute liver, kidney (female only) and spleen weights significantly lower than control; no effects on relative organ weights observed; significantly higher relative brain and adrenal gland weight in females and testes in males
500 ppm: no effects observed

Gross pathological findings:

effects observed, treatment-related

Description (incidence and severity):

No exposure-related changes were detected on necropsy examination of male rats. Hemorrhage involving the glandular stomach (minimal severity) was observed in two 3000 ppm female rats. White discoloration in the non-glandular stomach was also observed for these animals. No changes were seen in female rats from the 1500 and 500 ppm groups.

Neuropathological findings:

not examined

Histopathological findings: non-neoplastic:

effects observed, treatment-related

Description (incidence and severity):

3000 ppm: changes observed in nasal passage (degeneration of olfactory epithelium, mild to moderate) and stomach; Olfactory epithelium was replace in some areas by transitional or respiratory epithelium. 3/10 female rats had acute inflammation and degenerative lesions (minimal to mild) of the stomach mucosa (glandular vs forestomach), which was probably stress related. 1 male had atrophy of the thymus, but this was not considered to be a direct compoundrelated effect and rather attributed to stress.
1500 ppm: changes observed in nasal passage (degeneration of olfactory epithelium, 4/10 males and 6/10 females, minimal to mild) and stomach; Olfactory epithelium was replace in some areas by transitional or respiratory epithelium.
500 ppm: no effects observed

Histopathological findings: neoplastic:

not examined

Other effects:

no effects observed

Description (incidence and severity):

No dose-related or statistically significant effect on epidydimidal or testicular sperm count was observed compared with controls, although the epididymidal sperm counts for all treated groups were lower than controls. Effects on testicular staging or spermatogenic were not evaluated due to the unacceptable condition of tissue.

Details on results:

Concentrations:
Nominal concentrations were generally 13-70 % higher than the analytical concentrations. The overall time-weighted average analytical concentrations of 548.4, 1487.5, and 3009.6 ppm for the male rats and 547.9, 1487.6, and 3008.8 ppm for the female rats were within 10 % of the target concentrations of 550, 1500, and 3000 ppm.

Key result

Dose descriptor:

NOEL

Effect level:

500 ppm

Based on:

test mat.

Sex:

male/female

Basis for effect level:

body weight and weight gain

clinical signs

food consumption and compound intake

histopathology: non-neoplastic

organ weights and organ / body weight ratios

Key result

Critical effects observed:

yes

Lowest effective dose / conc.:

1 500 ppm

System:

central nervous system

Organ:

other: Not centered on a specific organ but general effects on neurological and behavioral functions as typically observed for alcohols (drowsiness and dizziness).

Treatment related:

yes

Dose response relationship:

yes

Relevant for humans:

yes

Key result

Critical effects observed:

yes

Lowest effective dose / conc.:

1 500 ppm

System:

respiratory system: upper respiratory tract

Organ:

nasal cavity

Treatment related:

yes

Dose response relationship:

yes

Relevant for humans:

no

Decreased body weight and feed consumption were noted for the 1500 and 3000 ppm groups, but there was no systemic or organ-specific toxicity. Degeneration of the olfactory epithelium at concentrations of 1500 and 3000 ppm was observed in areas of the nasal cavity that have demonstrated carboxylesterase activity (Bogdanffy, 1990: Biotransformation enzymes in the rodent nasal mucosa: the value of a histochemical approach. Environmental Health Perspectives 85, 177–186), but there was no evidence of pulmonary toxicity.

Endpoint conclusion

Endpoint conclusion:

adverse effect observed

Dose descriptor:

NOAEC

1 500 mg/m³

Study duration:

subchronic

Species:

rat

Quality of whole database:

The data was considered sufficiently reliable.

System:

central nervous system

Organ:

other: Not centered on a specific organ but general effects on neurological and behavioral functions (drowsiness and dizziness) as typically observed for alcohols as well as local irritation.

Repeated dose toxicity: inhalation - local effects

Link to relevant study records

Reference

Endpoint:

sub-chronic toxicity: inhalation

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:

EPA OTS 798.2450 (90-Day Inhalation Toxicity)

Deviations:

yes

Remarks:

tissues from central and peripheral nervous system were not examined histologically

GLP compliance:

yes

Limit test:

no

Specific details on test material used for the study:

- Analytical purity determined by GC

Species:

rat

Strain:

Sprague-Dawley

Remarks:

CRL:CD(SD)BR/VAF Plus

Details on species / strain selection:

Rats were chosen as common representative species for the study.

Sex:

male/female

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Source: Charles River Kingston, USA
- Females nulliparous and non-pregnant: yes
- Age at study initiation: ca. 60 d
- Mean weight at study initiation: 271+/-7 g (males); 215+/-8 g (females); the variability in body weight of individual animals in the selected population did not exceed 20 % of the mean for each sex
- Fasting period before study: no, food and water were not available during study
- Housing: Animals were housed in an Association for the Assessment and Accreditation of Laboratory Animal Care International-accredited vivarium; non-exposure period: individually in stainless-steel, wire-mesh cagesbin room seperated from exposure room
- Diet: Certified Rodent Diet (Agway Prolab RMH 3200 ground chow), ad libitum; not available during exposure
- Water: filtered municipal tap water from Monroe County (NY) water authority, ad libitum; not available during exposure
- Acclimation period: 12 days

DETAILS OF FOOD AND WATER QUALITY:
No known contaminants which would interfere with the outcome of this study were present in the feed. There have been no contaminants identified in previous water analyses that would be expected to interfere with the conduct of the study. Food analyses and semiannual analyses of water are maintained on file within the testing laboratory.

ENVIRONMENTAL CONDITIONS
- Temperature (°F): 67-75
- Humidity (%): 46-60
- Photoperiod (hrs dark / hrs light): 12/12

Route of administration:

inhalation: vapour

Type of inhalation exposure:

whole body

Vehicle:

air

Details on inhalation exposure:

GENERATION OF TEST ATMOSPHERE / CHAMBER DESCRIPTION
- Exposure apparatus: 4200 L stainless-steel and glass NYU-type inhalation chambers (Hinners or Laskin chamber)
- Source and rate of air: filtered, compressed air
- Method of conditioning air: The test atmosphere was generated by metering the test substance into glass distillation columns packed with glass beads; for the 1500 and 3000 ppm chambers, two serial distillation columns were used whereas only one column was used for the 500 ppm concentration. Filtered, compressed air was passed through the glass bead-packed columns to evaporate the test substance. The test substance delivery rate and air flow rate were adjusted to produce the desired. The distillation columns were heated to ~ 50 °C to enhance vaporization.
- Temperature, humidity, pressure in air chamber: The temperature and humidity were maintained at 20.6–24.7 °C and 36.7–68.7 % under negative pressure.
- Air change rate: 12–14 air changes per h
- Method of particle size determination: Micro Laser Particle Counter (model /xLPC-301, Particle Measuring Systems, Inc., Boulder, CO)
- Other:
The oxygen content of the chamber exposure atmosphere was at least 19.0 %.

TEST ATMOSPHERE
- Brief description of analytical method used: Chamber vapor concentrations were monitored with a multipositional air sampling and analysis system. The system consisted of a single MIRAN® IA infrared gas analyzer (Wilks Foxboro Analytical, South Norwalk, CT) and a computer-operated four-port sampling valve (Valco Instruments, Houston, TX). Each chamber was sampled at least once per hour.
- Samples taken from breathing zone: not specified


The animals were individually housed in the chamber, and their location within the chamber was moved periodically according to a defined rotation scheme to eliminate any effect due to placement in the chamber.

Analytical verification of doses or concentrations:

yes

Details on analytical verification of doses or concentrations:

Chamber vapor concentrations were monitored with a multipositional air sampling and analysis system at least once each hour with an infrared gas analyzer set at a wavelength of 3.38 µm.
The nominal concentration was calculated by dividing the amount of test substance consumed from the reservoir (determined gravimetrically) by the total chamber air flow.

Duration of treatment / exposure:

6 h/day

Frequency of treatment:

5 days per week (Monday to Friday) for 13 consecutive weeks (65 days), surviving animals were exposed for 1 (male) or 2 (females) days in week 14.

Dose / conc.:

500 ppm

Dose / conc.:

1 500 ppm

Dose / conc.:

3 000 ppm

No. of animals per sex per dose:

15

Control animals:

yes, concurrent vehicle

Details on study design:

- Dose selection rationale:
The exposure concentrations were based on data from a two-week inhalation probe study of male rats exposed to 0, 750, 1500, or 3000 ppm of the test substance for two weeks. This study demonstrated that the test substance produced concentration-related reductions in general activity levels during exposure periods. Animals appeared to acclimate to the 750 and 1500 ppm concentrations but not to 3000 ppm. Mean body weights for the female 1500 ppm animals and for the 3000 ppm male and female animals were lower than the control group on Days 7 and 14, but no statistically significant differences were noted. Based on these results, 3000 ppm was selected as an exposure concentration that would produce overt signs of toxicity and 500 ppm was selected as an exposure concentration that was expected to have no effect. An exposure concentration of 1500 ppm was selected as the intermediate exposure concentration.
For 500 ppm the target analytical concentration was increased to 550 ppm due to varying concentrations at different places in the chamber, so that the actual exposure to the animals would be closer to 500 ppm.

Positive control:

Not conducted.

Observations and examinations performed and frequency:

CAGE SIDE OBSERVATIONS: Yes
- Time schedule: once a day on weekends
- Cage side observations included, but were not limited to, examination of the hair, skin, eyes and mucous membranes, motor activity, feces, urine, respiratory system, circulatory system, autonomic nervous system, central nervous system, and behavior patterns. Tapping on chamber to assess animals response was done.

DETAILED CLINICAL OBSERVATIONS: Yes
- Time schedule: before and after exposure (during handling)

BODY WEIGHT: Yes
- Time schedule for examinations: weekly prior to exposure; fasted body weights were measured after exsanguination but prior to necropsy

FOOD CONSUMPTION AND COMPOUND INTAKE:
Food consumption was measured weekly prior to exposure, on Day 7, 14 and weekly afterwards.
- Food consumption for each animal determined and mean daily diet consumption calculated as g food/animal/day: Yes
- Compound intake calculated as time-weighted averages from the consumption and body weight gain data: Not specified

FOOD EFFICIENCY:
- Body weight gain in kg/food consumption in kg per unit time X 100 calculated as time-weighted averages from the consumption and body weight gain data: No

OPHTHALMOSCOPIC EXAMINATION: Yes
- Time schedule for examinations: prior to the start of the study; last week of exposure
- Dose groups that were examined: before study all animals; last exposure week from control and high-concentration group (No changes were detected in the eyes of the high-concentration animals and therefore the animals from the low- and mid-concentration were not examined.)

HAEMATOLOGY: Yes
- Time schedule for collection of blood: day 30, day after last exposure
- Anaesthetic used for blood collection: Yes, Metofane
- Animals fasted: Yes
- How many animals: day 30: 5 male and 5 female of each group, after last exposure: all remaining animals
- Whole blood samples were analyzed for red blood cell count, total white blood cell counts, hemoglobin, hematocrit and red blood cell. Prothrombin time was measured. Slides with blood smears were stained and examined for cellular morphology, differential white blood cell count and platelet count.

CLINICAL CHEMISTRY: Yes
- Time schedule for collection of blood: day 30, day after last exposure
- Animals fasted: Yes
- How many animals: day 30: 5 male and 5 female of each group, after last exposure: all remaining animals
- Serum samples were analyzed for total protein, total bilirubin, calcium, phosphorous, urea nitrogen, creatinine, glucose, gamma-glutamyltransferase, aspartate aminotransferase, alanine aminotransferase, sorbitol dehydrogenase and alkaline phosphatase. Albumin concentration and isozyme profile were determined. The albumin/globulin ratio was calculated from total protein and albumin concentrations. Serum sodium, chloride and potassium concentrations were measured.

URINALYSIS: Yes.
Urine was assessed as part of the cage side observations but parameters and methods of analysis were not further specified.

NEUROBEHAVIOURAL EXAMINATION: Yes
Neurobehavioural examinations were assessed as part of the cage side observations but parameters and methods of analysis were not further specified.

IMMUNOLOGY: No

Sacrifice and pathology:

GROSS PATHOLOGY: GROSS PATHOLOGY: Yes.
- Collected tissues are listed in table 1
- Wet weights of the liver, kidneys, testes or ovaries, spleen, adrenal glands, lungs and brain were recorded for all animals at necropsy. Paired organs were weighed together, except for the testes, which were weighed individually.

HISTOPATHOLOGY: Yes
- H&E stained tissues are indicated in table 1.
- All those tissues were examined microscopically from the control and high-concentration groups. In addition, the lungs, nasal passages, thymus (males only), stomach (females only), and gross lesions were examined from the mid-and low-concentration groups.

Other examinations:

The left testis and left epididymis of each male rat were placed into individual bags and frozen at - 25 °C. The right testis was preserved in 10 % buffered formalin. Both frozen and preserved samples of testes and epididymis were submitted to Research Triangle Institute, Research Triangle Park, NC for sectioning and evaluation of sperm morphology and development. The results are expressed per gram tissue weight.

Statistics:

Mean values were calculated for analytical concentration, chamber temperature, chamber relative humidity, body weight, feed consumption, serum chemistry, hematology, and organ weights. Body weight, feed consumption, serum chemistry, hematology, organ weight and sperm count data were evaluated using the following statistical tests: Bartlett’s test (P<=0.01), one-way analysis of variance (ANOVA) (P<=0.05), and Duncan’s multiple range test (P<=0.05) or Dunnett’s test to indicate statistical significance. If the Bartlett’s test indicated unequal variances, the data were evaluated using the Kruskal–Wallis H-test and the Mann–Whitney U-test. A probability of P<=0.05 (two-tailed) was used to determine significance. If the Bartlett’s test indicated unequal variances, the data were evaluated using the Kruskal–Wallis H-test and the Mann–Whitney U-test.

Clinical signs:

effects observed, treatment-related

Description (incidence and severity):

3000 ppm: reduced activity levels (less movement, decreased alertness, and slower response) of generally minor severity during exposure, sialorrhea in 3 animals for no more than 1-2 exposure days, red discoloration of the chin hair in several females for no more than 1-2 exposure days
1500 ppm: normal for 5 h on day 0, normal for 1-2 h on day 1 and 2, afterwards reduced activity of generally minimal severity for the remainder of the daily exposure periods and all following exposures. Reduced activity of minimal severity was generally seen throughout daily exposures thereafter.
500 ppm: no observed effects

Mortality:

no mortality observed

Description (incidence):

No spontaneous mortality occurred during the study.

Body weight and weight changes:

effects observed, treatment-related

Description (incidence and severity):

- 3000 ppm: body weight significantly lower (P≤0.05) than control starting from day 7 (males) and 14 (females), weight gain were 62 % (male) and 78 % (female) of control group weight gain, body weight gain significantly lower (P≤0.05) than control (males: week 1, 2, 5-7; females: week 2, 4, 6)
- 1500 ppm: body weight significantly lower (P≤0.05) than control starting from day 42 (males) and 14 (females), weight gain were 77 % (male) and 70 % (female) of control group weight gain, body weight gain significantly lower (P≤0.05) than control (males: week 11; females: week 2)
- 500 ppm: not significantly different than control, weight gain were 90 % (male) and 107 % (female) of control group weight gain

Food consumption and compound intake (if feeding study):

effects observed, treatment-related

Description (incidence and severity):

- 3000 ppm: food consumption significantly lower (P≤0.05) than control during whole time for males and except day 84 and 91 for females, mean weekly feed consumption was 14-25 % (males) and 6-16 % (females) lower than the control group
- 1500 ppm: food consumption significantly lower (P≤0.05) than control (males: day 7, 35, 42, 49 56, 63, 70, 77, 84; females: all except day 91); mean weekly feed consumption was 4-17 % (males) and 10-15 % (females) lower than the control group
- 500 ppm: food consumption significantly lower (P≤0.05) than control (males: day 35, 42, 63, 70; females: day 7, 14); mean weekly feed consumption was 3-12 % lower for males and between 2 % higher and 7 % lower for females than the control group

Food efficiency:

not examined

Water consumption and compound intake (if drinking water study):

not examined

Ophthalmological findings:

no effects observed

Description (incidence and severity):

No changes were detected in the eyes of the high-concentration animals, therefore the animals from the low- and mid-concentration groups were not re-examined.

Haematological findings:

no effects observed

Description (incidence and severity):

hematologic parameters after 30 days :
No significant differences in hematologic parameters were seen after 30 days in all groups.
hematologic parameters after 90 days:
- 3000 ppm: significantly higher mean erythrocyte counts, hemoglobin concentration and hematocrit values after 90 days compared to control, mean eosinophil percentage (male only) was significantly higher
- 1500 ppm: no effects observed
- 500 ppm: no effects observed

blood cell morphology after 30 days
Spherocytosis and poikilocytosis were seen in blood smears of animals from most groups.
- 3000 ppm: polychromasia in 2 females, Howell-Jolly bodies in blood and anisocytosis in 1 female
- 0 ppm (control): polychromasia in 1 male
blood cell morphology after 90 days
Poikilocytosis was seen in blood smears of animals from groups.
- 1500 ppm: microcytosis in 1 male, anisocytosis
- 500 ppm: microcytosis in 1 male, spherocytosis in 2 males, anisocytosis
- 0 ppm (control): anisocytosis

All the values were within normal limits for rats of this age and for the age and strain of the animals used, therefore none of the differences were considered biologically significant.

Clinical biochemistry findings:

effects observed, treatment-related

Description (incidence and severity):

The observed changes were not considered to be toxicologically meaningful.
3000 ppm: significantly lower (approx. 1 Meq/L) mean sodium concentrations after 30 days, significantly lower mean albumin and total protein concentrations in females after 90 days
1500 ppm: significantly lower (< 4 Meq/L) mean chloride concentrations after 30 days, significantly higher mean sorbitol dehydrogenase activity in males after 90 days
500 ppm: no effects observed

Urinalysis findings:

not specified

Behaviour (functional findings):

not specified

Description (incidence and severity):

No effects were described besides those observed as clinical signs.

Immunological findings:

not examined

Organ weight findings including organ / body weight ratios:

effects observed, treatment-related

Description (incidence and severity):

3000 ppm: absolute liver, kidney, brain (male only) and spleen weights significantly lower than control; relative organ weights only significantly lower for spleen (male only); significantly higher relative brain, lungs and testes weight in males and adrenal gland weight for males and females
1500 ppm: absolute liver, kidney (female only) and spleen weights significantly lower than control; no effects on relative organ weights observed; significantly higher relative brain and adrenal gland weight in females and testes in males
500 ppm: no effects observed

Gross pathological findings:

effects observed, treatment-related

Description (incidence and severity):

No exposure-related changes were detected on necropsy examination of male rats. Hemorrhage involving the glandular stomach (minimal severity) was observed in two 3000 ppm female rats. White discoloration in the non-glandular stomach was also observed for these animals. No changes were seen in female rats from the 1500 and 500 ppm groups.

Neuropathological findings:

not examined

Histopathological findings: non-neoplastic:

effects observed, treatment-related

Description (incidence and severity):

3000 ppm: changes observed in nasal passage (degeneration of olfactory epithelium, mild to moderate) and stomach; Olfactory epithelium was replace in some areas by transitional or respiratory epithelium. 3/10 female rats had acute inflammation and degenerative lesions (minimal to mild) of the stomach mucosa (glandular vs forestomach), which was probably stress related. 1 male had atrophy of the thymus, but this was not considered to be a direct compoundrelated effect and rather attributed to stress.
1500 ppm: changes observed in nasal passage (degeneration of olfactory epithelium, 4/10 males and 6/10 females, minimal to mild) and stomach; Olfactory epithelium was replace in some areas by transitional or respiratory epithelium.
500 ppm: no effects observed

Histopathological findings: neoplastic:

not examined

Other effects:

no effects observed

Description (incidence and severity):

No dose-related or statistically significant effect on epidydimidal or testicular sperm count was observed compared with controls, although the epididymidal sperm counts for all treated groups were lower than controls. Effects on testicular staging or spermatogenic were not evaluated due to the unacceptable condition of tissue.

Details on results:

Concentrations:
Nominal concentrations were generally 13-70 % higher than the analytical concentrations. The overall time-weighted average analytical concentrations of 548.4, 1487.5, and 3009.6 ppm for the male rats and 547.9, 1487.6, and 3008.8 ppm for the female rats were within 10 % of the target concentrations of 550, 1500, and 3000 ppm.

Key result

Dose descriptor:

NOEL

Effect level:

500 ppm

Based on:

test mat.

Sex:

male/female

Basis for effect level:

body weight and weight gain

clinical signs

food consumption and compound intake

histopathology: non-neoplastic

organ weights and organ / body weight ratios

Key result

Critical effects observed:

yes

Lowest effective dose / conc.:

1 500 ppm

System:

central nervous system

Organ:

other: Not centered on a specific organ but general effects on neurological and behavioral functions as typically observed for alcohols (drowsiness and dizziness).

Treatment related:

yes

Dose response relationship:

yes

Relevant for humans:

yes

Key result

Critical effects observed:

yes

Lowest effective dose / conc.:

1 500 ppm

System:

respiratory system: upper respiratory tract

Organ:

nasal cavity

Treatment related:

yes

Dose response relationship:

yes

Relevant for humans:

no

Decreased body weight and feed consumption were noted for the 1500 and 3000 ppm groups, but there was no systemic or organ-specific toxicity. Degeneration of the olfactory epithelium at concentrations of 1500 and 3000 ppm was observed in areas of the nasal cavity that have demonstrated carboxylesterase activity (Bogdanffy, 1990: Biotransformation enzymes in the rodent nasal mucosa: the value of a histochemical approach. Environmental Health Perspectives 85, 177–186), but there was no evidence of pulmonary toxicity.

Endpoint conclusion

Endpoint conclusion:

adverse effect observed

Dose descriptor:

NOAEC

1 500 mg/m³

Study duration:

subchronic

Species:

rat

Quality of whole database:

The data was considered sufficiently reliable.

Repeated dose toxicity: dermal - systemic effects

Link to relevant study records

Reference

Endpoint:

short-term repeated dose toxicity: dermal

Type of information:

experimental study

Adequacy of study:

supporting study

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

data from handbook or collection of data

Qualifier:

no guideline followed

Principles of method if other than guideline:

Butan-1-ol was applied to rabbit skin and the effects were studied.

GLP compliance:

not specified

Limit test:

yes

Species:

rabbit

Strain:

not specified

Sex:

not specified

Type of coverage:

not specified

Vehicle:

unchanged (no vehicle)

Details on exposure:

The test substance was applied to nonabraded skin.

Analytical verification of doses or concentrations:

no

Duration of treatment / exposure:

5 h each exposure

Frequency of treatment:

12 times in 21 days

Dose / conc.:

100 other: %

No. of animals per sex per dose:

A total of 2 rabbits was used.

Control animals:

no

Observations and examinations performed and frequency:

No details on conducted observations were provided.

Sacrifice and pathology:

GROSS PATHOLOGY: Yes

HISTOPATHOLOGY: Yes

Clinical signs:

no effects observed

Dermal irritation:

effects observed, treatment-related

Description (incidence and severity):

Slight erythema was detected. The effect was reversible.

Mortality:

no mortality observed

Body weight and weight changes:

not examined

Food consumption and compound intake (if feeding study):

not examined

Food efficiency:

not examined

Water consumption and compound intake (if drinking water study):

not examined

Ophthalmological findings:

not examined

Haematological findings:

not examined

Clinical biochemistry findings:

not examined

Urinalysis findings:

not examined

Behaviour (functional findings):

not examined

Immunological findings:

not examined

Organ weight findings including organ / body weight ratios:

not examined

Gross pathological findings:

no effects observed

Description (incidence and severity):

No test substance related changes were detected on internal organs.

Neuropathological findings:

not examined

Histopathological findings: non-neoplastic:

effects observed, treatment-related

Description (incidence and severity):

Polymorpghonuclear infiltration in the upper dermis was detected. No keratin sloughing was observed and hair follicles appeard normal.

Histopathological findings: neoplastic:

not examined

Other effects:

not examined

Key result

Dose descriptor:

conc. level:

Effect level:

100 other: %

Based on:

test mat.

Sex:

not specified

Basis for effect level:

dermal irritation

Key result

Critical effects observed:

no

Endpoint conclusion

Endpoint conclusion:

no adverse effect observed

Repeated dose toxicity: dermal - local effects

Link to relevant study records

Reference

Endpoint:

short-term repeated dose toxicity: dermal

Type of information:

experimental study

Adequacy of study:

supporting study

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

data from handbook or collection of data

Qualifier:

no guideline followed

Principles of method if other than guideline:

Butan-1-ol was applied to rabbit skin and the effects were studied.

GLP compliance:

not specified

Limit test:

yes

Species:

rabbit

Strain:

not specified

Sex:

not specified

Type of coverage:

not specified

Vehicle:

unchanged (no vehicle)

Details on exposure:

The test substance was applied to nonabraded skin.

Analytical verification of doses or concentrations:

no

Duration of treatment / exposure:

5 h each exposure

Frequency of treatment:

12 times in 21 days

Dose / conc.:

100 other: %

No. of animals per sex per dose:

A total of 2 rabbits was used.

Control animals:

no

Observations and examinations performed and frequency:

No details on conducted observations were provided.

Sacrifice and pathology:

GROSS PATHOLOGY: Yes

HISTOPATHOLOGY: Yes

Clinical signs:

no effects observed

Dermal irritation:

effects observed, treatment-related

Description (incidence and severity):

Slight erythema was detected. The effect was reversible.

Mortality:

no mortality observed

Body weight and weight changes:

not examined

Food consumption and compound intake (if feeding study):

not examined

Food efficiency:

not examined

Water consumption and compound intake (if drinking water study):

not examined

Ophthalmological findings:

not examined

Haematological findings:

not examined

Clinical biochemistry findings:

not examined

Urinalysis findings:

not examined

Behaviour (functional findings):

not examined

Immunological findings:

not examined

Organ weight findings including organ / body weight ratios:

not examined

Gross pathological findings:

no effects observed

Description (incidence and severity):

No test substance related changes were detected on internal organs.

Neuropathological findings:

not examined

Histopathological findings: non-neoplastic:

effects observed, treatment-related

Description (incidence and severity):

Polymorpghonuclear infiltration in the upper dermis was detected. No keratin sloughing was observed and hair follicles appeard normal.

Histopathological findings: neoplastic:

not examined

Other effects:

not examined

Key result

Dose descriptor:

conc. level:

Effect level:

100 other: %

Based on:

test mat.

Sex:

not specified

Basis for effect level:

dermal irritation

Key result

Critical effects observed:

no

Endpoint conclusion

Endpoint conclusion:

no adverse effect observed

Additional information

Valid experimental data to assess systemic toxicity after repeated dosage were available only for the oral pathway. For the dermal and inhalative pathway, available data are very limited and/or not considered appropriate for assessment. Therefore, for the inhalative route, reliable data were taken from the read-across substance n-Butyl acetate (CAS-No. 123-86-4).

 

Oral

In a 90-day study with butan-1-ol (US EPA, 1986) four groups of male and female Sprague-Dawley rats (30/sex/group) were dosed orally once daily with 0, 30, 125, or 500 mg/kg/day for 6 weeks until the day of interim necropsy. After the interim sacrifice, all surviving rats were dosed daily until final sacrifice. Body weights and food consumption were recorded weekly and the rats were observed at least twice daily for mortality and overt signs of toxicity. Ophthalmologic examinations were done during the pretreatment period and again during week 13. Blood and urine for clinicopathologic evaluation were collected from a fifth group of 10 rats/sex prior to initiation of dosing, from all surviving rats scheduled for the interim sacrifice, and from the first 10 rats/sex/group at the final sacrifice. The first 10 male and 10 female rats from each group were scheduled for necropsy on day 43 or 44 and all remaining rats on day 92 or 93. Gross postmortem examinations were done on all rats. Organ weights were taken from rats sacrificed on day 92 or 93. After the final sacrifice, a complete histopathologic examination was done on all rats in the control and high-dose groups, and on all gross lesions. In addition, a histopathologic examination was done on any rat found or sacrificed in extremis.

The only unequivocal effects produced by butan-1-ol were ataxia and hypoactivity at the 500 mg/kg/day dose level. Ataxia and hypoactivity were not seen as treatment-related signs until the final six weeks of the study with maximum weekly incidences of 32% and29% respectively (These effects were seen only clearly in the second part of the study period as animal number was reduced and post-dose observations were performed more quickly.). Onset of ataxia and hypactivity was about 2-3 minutes after dosing and duration was less than one hour.No treatment-related clinical signs were seen at the 30 or the 125 mg/kg/day dose level.

Body weight and food consumption values were similar for control and all treated groups. No treatment-related effect was observed at the ophthalmoscopic examinations or in gross or microscopic evaluation of the tissues.

Three rats were found dead or sacrificed in extremis, but these deaths could not be attributed to the test article, butan-1-ol as they were related to dosing errors.

At the interim clinical pathologic evaluation, red blood cell count (RBC), packed cell volume (PCV), and hemoglobin (HGB) averages of the 500 mg/kg/day dose group females were 5 % below control averages. Although these differences were statistically significant, they were small and no difference between the parameters were observed in the males of the interim evaluation or between control and treated groups of either sex at the final evaluation. Therefore, even if the lower red blood cell parameters in the 500 mg/kg/day females were an actual treatment-related effect, it was small and transitory.

Conclusion:

Oral administration of butan-1-ol at 500 mg/kg/day produced ataxia and hypoactivity at a maximum weekly incidence rate of 32 and 29 %, respectively. A slight (5%) lower (compared to controls) red blood cell count (RBC), packed cell volume (PCV), and hemoglobin (HGB) concentration present only in the 500 mg/kg/day dose group females at the interim evaluation may have been treatment-related.

No treatment-related effect was observed at the 30 mg/kg/day or 125 mg/kg/day dose levels.

 

Butan-1-ol was administered via gavage to 20 male rats at concentrations of 0.04, 0.2, 1.0 and 5.0 mg/kg bw/d for 30 days. No details on clinical observations and other endpoints were provided. The only observations described were increased activation of alcoholdehydrogenase and katalase in serum, membrane lesions of hepatocytes and lysosomas and a not further specified decrease of adrenal weight in animals treated with 0.2 mg/kg bw/d and above. (Sinitsyna 2002 and 2003).

 

Inhalation

Male rats were exposed to 1-butanol at the concentration of 320 mg/m^3 for 3 months (5 h/day, 5 days/week), in dynamic inhalation chamber. Body weight showed no statistically significant differences and the body weight gain amounted to 0.75 g/ day. Prolonged exposure induced cytochrome P-450 in liver microsomes (p < 0.05), while protein content of liver microsomes, GSH level and liver wet weight were not statistically significant different. Further details on observations were not provided (Jajte 2003).

 

Groups of male rats inhaled the chemical in mean concentrations of 0, 0.45,1.36, 3.98 or 14.6 mg/m^3 for 30 days 24 h/d. A not further specified decrease of adrenal weight and an increase of biotransformation was observed in all dose groups. Signs of drowsiness and dizziness were detected starting with 1.36 mg/m^3 and hepatic effects were observed in animals treated with 3.98 mg/m^3 or more (Sinitsyna 2002 and 2003).

 

Subchronic effects of butan-1-ol were studied in 12 male Wistar rats each exposed to 50 or 100 ppm vapour for 6h/d and 5d/wk (Korsak et al. 1994). Relevant elements of a standard study for repeated exposure, including histopathological evaluation of tissues, were missing. Subsequently, no local effects could be detected in this inhalation study and therefore no assessment can be made from this study. A LOEL of 50 ppm based on effects on hematology and clinical chemistry can be determined. A decreased performance on the rotarod was observed at both concentrations and was considered as dose-related; however, the data were only reported in graphical form. Overall this study was considered as disregarded due to major deficiencies.

Dermal

Butan-1-ol was applied to rabbit skin under occlusive conditions for 12 times 5 h within 21 days (Omie et al. 1949). Drying of the skin was reported and on continuous exposure, cracking, furrowing and exfoliation of the epidermis. The observed effects were reversible. No systemic effects were described by the authors.

 

Inhalation studies with the read-across substance n-Butyl acetate

A definitive subchronic toxicity study was performed according to EPA guideline OTS 798.2450 (OPP/CMA 94030517, 1996). Groups of 15 male and 15 female Sprague-Dawley rats were whole-body exposed to vapour concentrations of ca. 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 weeks.

The time-weighted average analytical concentrations were within 10% of the target concentrations. The daily mean temperatures and relative humidity inside the chambers during exposure were 21.1 - 24.7°C and 36.7 - 68.7%, respectively.

No spontaneous mortality occurred during the study. Animals were observed for signs of toxicity prior to exposure, once per hour during exposure, and 30 minutes to one hour after exposure. Animals exposed to 3000 ppm had reduced activity levels during exposure which were of generally minor severity. Signs of sialorrhea and red discoloration on the chin hair were also observed. Animals exposed to 1500 ppm exhibited reduced activity during exposure of generally minimal severity. Control and 500 ppm animals appeared normal during exposure. After exposure, animals in all groups had porphyrin nasal discharges and dried porphyrin stains around the nose. These clinical signs were occasionally seen during the morning examination before exposure.

Mean body weights for the 3000 ppm group were significantly (p <= 0.05) lower than the control group for male rats on Days 7, 14, 21, 28, 35, 42, 49, 56, 63, 70, 77, 84, and 91, and for female rats on Days 14, 21, 28, 35, 42, 49, 56, 63, 70, 77, 84, and 91. Overall weight gains for the 3000 ppm group were 62 and 78 % of weight gains for the control group (males and females, respectively). Mean feed consumption for the 3000 ppm groups was significantly lower (p <= 0.05) than for the control group throughout the study for male rats and at all intervals except Days 84 and 91 for female rats. Mean weekly feed consumption values for the 3000 ppm groups were 14-25% lower than the control group for male rats and were 6-16% lower than the control group for female rats. Mean body weights for the male 1500 ppm group were significantly (p <= 0.05) lower than the control group on Days 42, 49, 56, 63, 70, 77, 84, and 91. Mean body weights for the female 1500 ppm group were significantly (p <= 0.05) lower than the control group on Days 14, 21, 28, 35, 42, 49, 56, 63, 70, 77, 84, and 91. Overall weight gains were 90 and 107% of the control group (males and females, respectively). Mean feed consumption values for the 1500 ppm groups were significantly lower (p <= 0.05) than for the control group on Days 7, 35, 42, 49, 56, 63, 70, 77, and 84 for male rats and at all intervals except Day 91 for female rats. Mean weekly feed consumption values for the 1500 ppm groups were 4-17 % lower than the control group for male rats and were 10-15% lower than the control group for female rats. Mean body weights for the 500 ppm groups were comparable to the control group throughout the study, and no statistically significant differences were noted. However, mean feed consumption values for the 500 ppm groups were significantly lower (p <= 0.05) than for the control group on Days 35, 42, 63, and 70 for male rats and on Days 7 and 14 for female rats. Mean weekly feed consumption values for the 500 ppm groups were 3-12 % lower than the control group for male rats and were from 2 % higher to 7 % lower than the control group for female rats.

Blood was collected from 5 animals per group after 30 days of exposure, and from 10 animals per group at termination. No significant differences in hematologic parameters were seen after 30 days of exposure; slightly higher erythrocyte counts, hematocrit levels, and hemoglobin concentrations were observed for the 3000 ppm male and female rats after 90 days on test. None of the differences were considered biologically significant, however. Evaluation of blood cell morphology did not suggest any compound-related effects. After 30 days of exposure, slight but significantly (p <= 0.05) lower mean sodium concentrations were observed for the male and female 3000 ppm groups compared with the control groups, and significantly lower (p <= 0.05) mean chloride concentration for the 1500 ppm male group compared with the control groups. No other differences in serum chemistries were seen among groups. After 90 days of exposure, minor but statistically significant changes were observed for mean albumin (lower) and total protein concentrations (lower) for the 3000 ppm female group, and mean sorbitol dehydrogenase activity (higher) for the 1500 ppm male group. These changes were not considered to be toxicologically meaningful, and no other differences in serum chemistry were observed among groups.

No treatment-related ophthalmologic changes were observed. Mean terminal body weights were significantly lower (p <= 0.05) for the 1500 and 3000 ppm male and female groups compared with the control group. Mean absolute weights of the liver, kidneys, and spleen were significantly lower (p <= 0.05), but relative organ weights (to body weight) were not significantly different except for the mean spleen-to-body weight ratio for the 3000 ppm male group which was significantly lower than for the control group. Reduced body weight was also reflected in the significantly lower (p <= 0.05) mean absolute brain weight for the 3000 ppm male group and significantly higher (p<= 0.05) mean brain-to-body weight for the 1500 ppm female and 3000 ppm male groups compared with their respective control groups. In addition, mean testes-to-body weights for the 1500 and 3000 ppm male groups and the mean relative lung (to body weight) weight for the 3000 ppm male group were significantly higher (p <= 0.05) than for the control group. Mean adrenal gland-to-body weight ratios for the 1500 ppm female and 3000 ppm male and female groups were significantly higher (p <= 0.05) than for the respective control groups.

Signs of irritation of the glandular stomach and necrosis in the non-glandular stomach were observed in two 3000 ppm female rats. No other compound-related changes were detected on necropsy examination of male or female rats exposed to the test substance. Signs of irritation were also seen microscopically in the nasal passages (necrosis of the olfactory epithelium) of some 1500 and all 3000 ppm rats. The severity of the olfactory lesion was mild to moderate for the 3000 ppm group and minimal to mild for the 1500 ppm group. No lesions were observed in the nasal passages of 500 ppm groups. Inflammation of the stomach mucosa (glandular or forestomach) was also observed microscopically in a few 3000 ppm female rats; this lesion may be due to stress. Other lesions that were observed microscopically were not considered to be compound-related. There was no effect on either epididymidal or testicular sperm counts.

In conclusion, exposures to n-butyl acetate vapors resulted in acute, transient signs of reduced activity levels during exposure to 1500 and 3000 ppm. Decreased body weight and feed consumption were noted for the 1500 and 3000 ppm groups, but there was no systemic, organ-specific toxicity. Signs of upper respiratory tract irritation were seen in the nasal passages of 1500 and 3000 ppm animals. The no-observed-effect level (NOEL) for this study is considered to be 500 ppm.

 

Additionally, data from a reliable subchronic neurotoxicity study are available which was performed to US EPA Pesticide Assessment Guidelines (OPP/CMA 297761P, 1996). The study consisted of two sets of animals, male and female ad libitum-fed Sprague-Dawley (SD) rats designated for functional observational battery, motor activity, and neuropathology endpoints (FOB/MA/NP) and male (SD) rats restricted to 12-14 g of feed per day and which were designated for schedule-controlled operant behavior (SCOB). Both sets of animals were exposed to concentrations of 0, 500, 1500, or 3000 ppm of n-butyl acetate for at least 65 exposures over 14 weeks. The animals were exposed in 4200 L glass and stainless steel chambers for 6 hours per day. Vapors of the test substance were generated by metering the liquid test substance through heated glass distillation columns packed with glass beads. The time-weighted average analytical concentrations were within 10% of the target concentrations. The target analytical concentration for the 500 ppm group was increased to 550 ppm after consultation with the Sponsor because determination of chamber atmosphere homogeneity showed that the variation in actual exposure concentration at various locations in the chamber was on average 13 % lower than the reference point. Nominal concentrations were generally 13-70% higher than the analytical concentrations. The daily mean temperatures and relative humidity inside the chambers during exposure were 21.9 - 23.0°C and 46.9 -53.7%, respectively.

No spontaneous mortality occurred during the study, however, one male control FOB/MA/NP animal (Rat 502) was euthanatized and necropsied on Day 78 due to poor physical condition and a body weight loss of 24 % over a two week period.

Animals were observed for signs of toxicity prior to exposure, once per hour during exposure, and 30 minutes to one hour after exposure. Animals exposed to 3000 ppm had reduced activity levels which were of minor severity during exposure. There was no evidence of a cumulative effect of exposure on the severity of reduced activity. Signs of sialorrhea, gasping, and red discoloration on the chin hair were also observed. Animals exposed to 1500 ppm exhibited reduced activity of generally minimal severity. There was no evidence of a cumulative effect of exposure on the severity of reduced activity. Control and 500 ppm animals appeared normal during exposure. There were no other apparent differences in the clinical condition of FOB/MA/NP and SCOB animals. After exposure, animals in all groups had porphyrin nasal discharges and dried porphyrin stains around the nose. These clinical signs were occasionally seen in the morning before exposure.

Mean body weights for the 3000 ppm ad libitum-fed group were significantly (p <= 0.05) lower than the control group for male rats on Days 7, 14, 21, 28, 35, 42, 49, 56, 63, 70, 77, 84, 91, and 98, and for female rats on Days 14, 21, 28, 35, 42, 56, 63, 70, 77, 84, 91, 98. Mean weight gains for the 3000 ppm ad libitum-fed male group during Weeks 1-3, 5-7, 11, and 14 were significantly (p <= 0.05) lower than for the control group. Mean weight gains for the 3000 ppm ad libitum-fed female group during Weeks 1-3, and 6 were significantly (p <= 0.05) lower than for the control group. Overall weight gains for the 3000 ppm groups (males and females, respectively) were 64 and 59 % of those for the control groups. No differences in body weight were seen for the 1500 ppm ad libitum-fed male group. Mean body weights for the female 1500 ppm ad libitum-fed group were significantly (p <= 0.05) lower than the control group during Weeks 6, 7, 10, 11, 12, 13, and 14. Mean weight gains for the 1500 ppm male ad libitum-fed group were significantly (p <= 0.05) lower than for the control groups during Weeks 9 and 14, while mean weight gains for the 1500 ppm ad libitum-fed female group were significantly (p <= 0.05) lower than for the control groups during Weeks 6 and 11. Overall weight gains for the 1500 ppm groups (males and females, respectively) were 82 and 74% of those for the control groups. Mean body weights and weight gains for the 500 ppm ad libitum-fed groups were comparable to the control groups throughout the study. No differences in body weight were noted among the male SCOB rats.

Neurotoxicity was evaluated in ad libitum-fed animals using an FOB and quantitative measurement of motor activity during Weeks -1, 4, 8, and 13, and neuropathology at termination. SCOB testing occurred daily in feed-restricted male rats during Weeks 1-13 of exposure and Weeks 14 and 15 following the cessation of exposure. No evidence of neurotoxicity was seen during the FOB examinations. Minor changes in severity scores of isolated FOB parameters were noted, but these were not considered to be toxicologically or neurobehaviorally significant. Mean total motor activity for the 3000 ppm male group was significantly (p <= 0.05) higher than for the control group during Week 4. Mean total motor activity counts for all male groups were closer to baseline values during Weeks 8 and 13 and no significant differences were observed among groups. No time-treatment interactions were observed in total ambulations for male groups. No significant motor activity differences were present for female rats. No significant differences were seen in SCOB at any test vapor concentration. No treatment-related changes were detected during gross necropsy examinations of male or female FOB/MA/NP rats exposed to the test substance. Microscopic evaluations of sections from the brain, spinal cord (cervical and lumbar regions), dorsal and ventral spinal roots, dorsal root ganglia, sciatic nerve, and tibial nerve of animals in the control and 3000 ppm groups did not indicate any treatment-related effects.

This study fulfills the requirements of the U.S. Environmental Protection Agency, Neurotoxicity Pesticide Assessment Guidelines, Subdivision F, Hazard Evaluation: Human and Domestic Animals, addendum 10, Series 81, 82, and 83 (1991) as specified in the Enforceable Consent Agreement of the Testing Consent Order. Exposures to n-butyl acetate vapors resulted in acute, transient signs of reduced activity levels on a daily basis at 1500 and 3000 ppm, but no evidence of a cumulative effect on activity during the 13-week exposure. In addition, there was no evidence of neurotoxicity based on FOB, motor activity, neuropathology, and SCOB endpoints. Therefore, the no-observable effect level (NOEL) for subchronic neurotoxicity for this study is 3000 ppm based on the lack of cumulative neurotoxicity following repeated exposure.

Justification for classification or non-classification

The CNS effects observed in the repeated dose studies were not centered on a specific organ but considered as general impairments of neurological and behavioral functions (drowsiness and dizziness) which are classified accordingly (STOT SE 3, H336). Those observations typically occur for alcohols and there is currently no need for classification of butan-1 -ol for repeated dose systemic toxicity.

 

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 repeated dose systemic toxicity via oral, inhalative or dermal route under Regulation (EC) No 1272/2008, as amended for the ninth time in Regulation (EU) No 2016/1179.