Pentan-1-ol

Endpoint summary

Key value for chemical safety assessment

Effects on fertility

Description of key information

No adverse effects on organs with reproductive functions were found in a subchronic gavage study up to the limit dose. Related pentanols did not cause adverse effects on fertility and organs with reproductive functions in subchronic drinking water studies in rats.

Link to relevant study records

Reference

Reference 1

Endpoint:

reproductive toxicity, other

Remarks:

subchronic repeated dose toxicity study

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

Qualifier:

equivalent or similar to guideline

Guideline:

other: OECD Guideline 408 (Repeated Dose 90-Day Oral Toxicity in Rodents)

Deviations:

yes

Remarks:

15 animals per sex per dose, no ophthalmological examinations

GLP compliance:

no

Limit test:

no

Species:

rat

Strain:

other: ASH/CSE

Sex:

male/female

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Source: from a specified-pathogen-free breeding colony
- Weight at study initiation: 91.8 ± 2.1
- Diet (e.g. ad libitum): Spillers' Laboratory Small Animal Diet
- Water (e.g. ad libitum): tap-water

ENVIRONMENTAL CONDITIONS
- Temperature (°C): 20 ± 1
- Humidity (%): 40 - 60

Route of administration:

oral: gavage

Vehicle:

corn oil

Details on exposure:

VEHICLE
- Concentration in vehicle: in appropriate concentration so that all rats received a dosage of 5 ml/kg/day

Analytical verification of doses or concentrations:

not specified

Duration of treatment / exposure:

13 weeks

Frequency of treatment:

daily

Remarks:

Doses / Concentrations:
50, 150, 1000 mg/kg bw/day
Basis:
actual ingested

No. of animals per sex per dose:

15

Control animals:

yes, concurrent vehicle

Parental animals: Observations and examinations:

BODY WEIGHT: Yes
- Time schedule for examinations: initially, then at days 1, 2 and 6 and at intervals of not more than 1 week up to thereafter (last weighing: days 91)

FOOD CONSUMPTION CONSUMPTION:
- Food consumption for each animal determined and mean daily diet consumption calculated as g food/kg body weight/day: Yes

WATER CONSUMPTION: Yes
- Time schedule for examinations: food and water consumptions were measured over the 24-hour period preceding the day of weighing

Postmortem examinations (parental animals):

GROSS PATHOLOGY: Yes, at autopsy all the tissues were examined for gross abnormalities and the brain, heart, liver, spleen, kidneys, stomach, small intestine, caecum, adrenals, gonads, pituitary and thyroid were weighed.
HISTOPATHOLOGY: Yes, samples ot the above organs and of lung, lymph nodes, salivary gland, trachea, oesophagus, aortic arch, thymus, urinary bladder, colon, rectum, pancreas, uterus and skeletal muscle were preserved in 10% buffered formalin. Paraffin-wax sections of these tissues were stained with haematoxylin and eosin for microscopic examination, which was carried out on liver and kidney sections from all animals but on other types of tissue from only half of the control rats and from those given 1000 mg test substance/kg bw for 13 weeks.

CLINICAL SIGNS AND MORTALITY
No abnormalities in appearance or behaviour were seen during the study

BODY WEIGHT AND WEIGHT GAIN, FOOD CONSUMPTION AND WATER CONSUMPTION
There were no significant differences between the treated and control rats in body weight or in food and water consumption (see table 1).

HAEMATOLOGY AND CLINICAL CHEMISTRY (see table 2)
Only isolated differences from the controls were seen in the results of the haematological studies. These included a lower total leucocyte count at week 2 in the male rats given 150 or 1000 mg test substance/kg bw/day and lower haemoglobin concentrations at week 13 in the male animals given 50 or 1000 mg/kg bw/day. Also there were higher percentages of reticulocytes in the male rats given 1000 mg/kg bw/day at week 2 and in the females at week 13, as well as a slightly lower percentage of lymphocytes at week 6 in the females given 1000 mg/kg bw/day. The results of the serum analyses were similar in test and control rats.

URINALYSIS
The urine was free from bile, blood, glucuse and ketones, while the concentration of albumin was similar in all groups. At week 6 there were lower cell counts in the urine of the male rats given 150 or 1000 mg test substance/kg bw/day, the differences being statistically significant. Some statistically significant differences were also apparent in the concentration tests at week 12; the specific gravity of the samples collected at 16-20 hour from females given 1000 mg/kg bw/day was higher than the control value and the volume was lower. After the same period on test, the male rats given 50 or 1000 mg/kg/day produced less urine in the 6-hour period without water. No differences from the controls were found in the dilution test nor at week 2 and 6 in the concentration tests.

ORGAN WEIGHTS (see table 3)
Examination of the organ weights showed some isolated differences at week 2, but none thereafter. The stomach weights in the males and females given 1000 mg n-amyl alcohol/kg bw/day were higher than those of the controls, but the difference was confined to the male rats when the values were related to body weight. Also, a higher heart weight was found in the female rats given the top level of treatment, but this was not evident when the figure was related to body weight. Relative to body weight, the spleens from the female rats dosed with 1000 mg/kg bw/day showed a low value, as did the female kidney weights, both at this and at the 150 mg/kg bw/day level.

GROSS PATHOLOGY
At autopsy, no abnormalities were seen at any dose level

HISTOPATHOLOGY: NON-NEOPLASTIC
On histological examination, protein casts and foci of calcification were found in the kidney tubules, particularly from the male animals, but the incidences were similar in the treated animals and their corresponding controls. The incidence of fatty change and inflammatory cell infiltration in the liver was again comparable in the control and treated rats. No histological changes related to the period or level of treatment were seen in any of the organs examined.

Dose descriptor:

NOAEL

Effect level:

1 000 mg/kg bw/day (actual dose received)

Based on:

test mat.

Sex:

male/female

Basis for effect level:

other: no effects on reproductive organs (gross pathology, histopathology)

Remarks on result:

not measured/tested

Reproductive effects observed:

not specified

Table 1: Mean body weights and food and water consumption values of rats given daily doses of 0 - l000 mg test substance/kg bw/day for l3 weeks

Dose level (mg/kg bw/day) Body weight (g) at day Mean food consumption (g/rat/day) Mean water consumption (ml/rat/day) 0 34 62 91 0 (males)       93 323 424 467 18.8 26.2 50 91 326 422 470 18.9 24.3 150 91 336 449 504 19.6 24.3 1000 96 316 426 479 18.0 24.3 0 (females) 91 211 256 281 14.7 20.6 50 91 211 259 286 14.9 20.5 150 89 217 268 293 15.1 21.6 1000 92 205 250 276 14.9 22.1

 

Table 2: Haematological values (aortic blood) for rats given daily doses of 0 -1000 mg test substance/kg bw/day

dose level (mg/kg bw/day) Number of rats Hb (g/100 ml) PCV (%) RBC (10^6/mm^3) Retics (% of RBC) Leucocytes Total (10^3/mm^3) Differential (%) N E L M Week 2 0 (male) 5 12.7 41 5.40 1.4 7.1 11 1 85 3 150 5 12.7 41 5.80 - 5.5* 11 0 86 3 1000 5 13.0 42 5.15 2.3* 5.0* 12 1 85 2 0(female) 4 13.5 45 5.15 1.3 3.7 11 0 87 2 150 5 12.6 44 5.85 - 4.5 10 0 89 1 1000 5 13.0 44 5.74 1.0 4.6 11 1 86 2 Week 6 0 (male) 5 14.5 47 6.79 0.5 8.3 11 0 88 1 150 5 14.6 48 6.97 - 8.9 - - - - 1000 5 14.0 46 6.76 0.4 5.6 7 0 91 2 0(female) 5 14.3 45 6.70 0.2 5.6 8 0 91 1 150 5 13.7 43 6.60 - 5.5 - - - - 1000 5 14.1 44 6.76 0.1 6.6 18 1 79* 2 Week 13 0 (male) 14 14.1 45 6.90 0.6 5.6 17 1 80 2 50 15 13.4* 43 6.58 - 5.4 - - - - 150 15 13.9 44 6.64 - 5.4 - - - - 1000 15 13.6* 44 6.66 0.8 5.4 18 2 79 2 0(female) 13 14.0 43 6.56 0.3 4.7 10 1 87 2 50 14 13.5 43 6.51 - 4.4 - - - - 150 14 13.8 43 6.45 - 4.4 - - - - 1000 15 13.7 43 6.65 0.6* 3.9 12 1 85 2 Hb: haemoglobin, PCV: packet cell volume, RBC: red blood cells, Retics: reticulocytes, N: neutrophils, E: eosinophils, L: lymphocytes, M: monocytes, *: significantly different

Table 3: mean relative organ weights of rats given daily doses of 0 -1000 mg test substance/kg bw/day for 2 or 13 weeks

Sex and dose level (mg/kg/day) Number of rats Relative organ weight (g/100 g body weight) Terminal body weight (g) Brain Heart Liver Spleen Kidneys Stomach Small intestine Caecum Adrenals (mg/100g) Gonads* Pituitary (mg/100g) Thyroid (mg/100g) Week 2 0 (male) 5 1.04 0.45 3.59 0.36 0.88 0.62 4.75 0.47 24.24 1.25 3.5 8.0 164 150 5 0.99 0.47 3.68 0.38 0.90 0.70 4.89 0.49 25.42 1.21 3.5 6.9 164 1000 5 0.98 0.46 3.75 0.37 0.92 0.72* 4.47 0.49 27.87 1.28 4.0 6.7 164 0(female) 5 1.14 0.44 4.13 0.38 0.96 0.70 4.45 0.42 35.36 61.7 6.3 8.4 137 150 5 1.11 0.46 3.83 0.33 0.86* 0.64 4.14 0.43 35.84 60.9 6.1 9.2 144 1000 5 1.05 0.47 3.74 0.31* 0.85* 0.68 3.84 0.44 36.71 54.8 5.9 9.2 150 Week 13 0 (male) 15 0.42 0.31 2.68 0.17 0.64 0.41 2.02 0.22 15.66 0.83 2.9 4.7 546 50 15 0.42 0.30 2.73 0.18 0.63 0.42 2.19 0.21 15.05 0.81 2.6 4.8 561 150 15 0.40 0.30 2.72 0.19 0.61 0.41 2.21 0.23 14.76 0.80 2.7 4.4 491 1000 15 0.41 0.31 2.69 0.19 0.64 0.43 1.98 0.23 15.19 0.81 2.8 4.9 474 0(female) 15 0.66 0.34 2.49 0.25 0.63 0.53 2.52 0.29 28.10 54.9 5.2 7.0 270 50 15 0.66 0.34 2.49 0.24 0.65 0.53 2.53 0.31 29.45 53.2 5.3 6.5 268 150 15 0.63 0.35 2.49 0.25 0.64 0.53 2.59 0.29 27.74 54.7 5.1 6.6 276 1000 15 0.66 0.37 2.36 0.24 0.62 0.50 2.43 0.31 28.36 54.0 4.7 7.5 268 *mg/100 g body weight for female gonads; *: significantly different

Reference 2

Endpoint:

extended one-generation reproductive toxicity - basic test design (Cohorts 1A, and 1B without extension)

Type of information:

read-across based on grouping of substances (category approach)

Adequacy of study:

weight of evidence

Study period:

Feb 2018 - Oct 2019

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Justification for type of information:

For justification of read across please refer to section 13.

Qualifier:

according to guideline

Guideline:

OECD Guideline 443 (Extended One-Generation Reproductive Toxicity Study)

Version / remarks:

Jul 2011

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Limit test:

no

Justification for study design:

Study design according to ECHA final decision CCH-D-2114346807-40-01/F

Specific details on test material used for the study:

SOURCE OF TEST MATERIAL
- Source: BASF SE
- Batch No.of test material: 59086375L0
- Expiration date of the lot/batch: 17 Jan 2019
- Purity: 99.7%
- Appearance: Liquid/colorless clear

STABILITY AND STORAGE CONDITIONS OF TEST MATERIAL
- Storage condition of test material: Room temperature
- Stability under test conditions: guaranteed and verified
- Homogeneity: given

TREATMENT OF TEST MATERIAL PRIOR TO TESTING
- Treatment of test material prior to testing: The required quantities of test substance, depending on the dose group, were weighed into appropriate beakers. A vessel with a capacity of 30L (equipped with a with magnetic rod) was tared to 0g. Then 10L of drinking water were added. The test substance was completely transferred from the beaker into the vessel, the beakers rinsed with further amounts of drinking water. Afterwards an appropriate amount of drinking water was added to obtain the desired concentrations for the different dose groups. These preparations were stirred until the test substance was completely dissolved.

Species:

rat

Strain:

Wistar

Remarks:

Crl:WI(Han)

Details on species / strain selection:

The rat is the preferred animal species for reproduction studies according to test guidelines.
This strain was selected since extensive historical control data were available for Wistar rats.

Sex:

male/female

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Source: Charles River Laboratories, Germany
- Females nulliparous and non-pregnant: yes
- Age at study initiation: (P) 34 (+/-1) days; (F1) 3 wks
- Weight at study initiation: females (mean) 110 g; males (mean) 108.5 g
- Fasting period before study: no
- Housing: five per cage, females after weaning and males postmating: single
- Diet: ad libitum
- Water: ad libitum
- Acclimation period: about 6 days

ENVIRONMENTAL CONDITIONS
- Temperature (°C): 20-24
- Humidity (%): 45-65
- Air changes (per hr): 15
- Photoperiod (hrs dark / hrs light): 12/12 (6 am to 6 pm)

IN-LIFE DATES: From: 20 Feb 2018 To: F1: 26 - 30 Jun and 02 Jul 2018; F0M: 12 - 14 Jun 2018
F0F: 14 May and 3 - 4 Jul 2018; 1A: 31 Aug and 03 - 05 Sep 2018, 1B: 29 - 30 Aug and 6 - 7 Sep 2018

Route of administration:

oral: drinking water

Vehicle:

water

Details on exposure:

DIET PREPARATION
- Rate of preparation of diet (frequency): continuous
- Mixing appropriate amounts with (Type of food): drinking water

VEHICLE
- water

Details on mating procedure:

- M/F ratio per cage: 1/1
- Length of cohabitation: max 2 weeks; about 16.00 h until 6.30 - 9.00 h of the following morning.
- Proof of pregnancy: sperm in vaginal smear referred to as day 0 of pregnancy
- After successful mating each pregnant female was caged (how): group

Analytical verification of doses or concentrations:

yes

Details on analytical verification of doses or concentrations:

Analyses were carried out at the beginning and toward the end of the premating phase, in female drinking water once in the lactation period as well as for cohort 1A and 1B animals toward the end of the postweaning period.

Duration of treatment / exposure:

F0 males: 10 weeks pre-mating, 2 weeks mating, 3 weeks post-mating
F0 females: 10 weeks pre-mating, 2 weeks mating, pregnancy and lactation

F1: In-utero, pre-weaning, post-weaning and cohort 1A and 1B 10 weeks post-weaning

Frequency of treatment:

daily

Details on study schedule:

100 males and females were treated for a minimum of 10 weeks, then males and females from the same dose group were mated, overnight at a ratio of 1:1. Females were allowed to deliver pups until PND 4 or PND 21 or PND 22 (depending on the cohort). Pups of the F1 litter were selected (F1 rearing animals) and assigned to 2 different cohorts which were subjected to specific postweaning examinations. On PND 4 blood samples were collected from a maximum of 10 surplus (culled) F1 pups per sex and group. On PND 22 blood samples were collected from 10 surplus F1 pups per sex and group.
Blood samples were taken from 10 animals per test group of the F0 parental animals and cohort 1A animals.
Shortly before weaning of the F1 pups the F0 generation parental male animals were sacrificed.
After weaning of F1 pups the F0 generation parental female animals were sacrificed.

Dose / conc.:

1 250 ppm

Dose / conc.:

3 750 ppm

Dose / conc.:

12 500 ppm

No. of animals per sex per dose:

25 (F0), 20 (F1A), 25 (F1B)

Control animals:

yes, concurrent vehicle

Details on study design:

- Dose selection rationale: The doses were selected based on a previously conducted screening OECD guideline 422 study with 3-Methyl-1-butanol (BASF 2018). In this present study, a NOAEL for general systemic toxicity was observed around the limit dose (1000 mg/kg bw). Therefore a similar high-dose was chosen.
- Rationale for animal assignment (if not random): random
- Fasting period before blood sampling for clinical biochemistry: not specified
- Other: During the lactation period the test substance concentrations in the drinking water of the F0 females were reduced to 50%. This drinking water adjustment derived from historical body weight and water consumption data maintained the dams at the desired target doses of the test substance during this period of increased water intake.

Positive control:

not included

Parental animals: Observations and examinations:

CAGE SIDE OBSERVATIONS: Yes
- Time schedule: at least once daily

DETAILED CLINICAL OBSERVATIONS: Yes
- Time schedule: weekly

BODY WEIGHT: Yes
- Time schedule for examinations: once a week, except during pregnancy and lactation; GD 0-4, 4-7, 7-10, 10-14, 14-17 and 17-20 and PND 1-4, 4-7, 7-10, 10-14, 14-17, 17-20 and 20-21, respectively.

FOOD CONSUMPTION:
- Time schedule: once a week, except: not determined after the 10th premating week (male F0 animals) and during the mating period, During pregnancy, food consumption of the F0 females with evidence of sperm was determined weekly for GD 0-7, 7-14 and 14-20, During lactation, food consumption of the F0 females, which gave birth to a litter was determined for PND 1-4, 4-7, 7-10, 10-14, 14-18 and 18-21.

WATER CONSUMPTION AND COMPOUND INTAKE (if drinking water study): Yes
- Time schedule for examinations: Over a period of 3 days, except during pregnancy and lactation GD 0-1, 4-5, 7-8, 10-11, 14-15, 17-18 and 20-21 and PND 1-2, 4-5, 7-8, 10-11, 14-15, 17-18 and 20-21, respectively.

CLINICAL PATHOLOGY
- Time schedule: At termination from 10 F0 parental and cohort 1A males and females

HEMATOLOGY: Yes
Parameters analyzed: Leukocyte count (WBC), Erythrocyte count (RBC). Hemoglobin (HGB), Hematocrit (HCT), Mean corpuscular volume (MCV), Mean corpuscular hemoglobin (MCH), Mean corpuscular hemoglobin concentration (MCHC), Platelet count (PLT), Differential blood count, Reticulocytes (RETA), Prothrombin time

CLINICAL CHEMISTRY: Yes
Parameters analyzed: Alanine aminotransferase (ALT), Aspartate aminotransferase (AST), Alkaline phosphatase (ALP), -Glutamyltransferase (GGT), Sodium (NA), Potassium (K), Chloride (CL), Inorganic phosphate (INP), Calcium (CA), Urea (UREA), Creatinine (CREA), Glucose (GLUC), Total bilirubin (TBIL), Total protein (TPROT), Albumin (ALB), Globulins (GLOB), Triglycerides (TRIG), Cholesterol (CHOL), Total thyroxine (T4), Thyroid stimulating hormone (TSH)

URINALYSIS: Yes
Parameters analyzed: pH, Protein (PRO), Glucose (GLU), Ketones (KET), Urobilinogen (UBG), Bilirubin (BIL), Blood, Specific gravity (SP.GR.) [g/L], Sediment, Color turbidity (COL, TURB), Volume (VOL) [mL]

Oestrous cyclicity (parental animals):

Evaluated by daily analysis of vaginal smear for all F0 female parental rats for a minimum of 3 weeks prior to mating. In all cohort 1A females, vaginal smears were collected after vaginal opening until the first cornified smear (estrous) was recorded. The estrous cycle also was evaluated in cohort 1A and 1B females for 2 weeks around PND 75.

Sperm parameters (parental animals):

Parameters examined in all F0 male parental and cohort 1A male generations: sperm head count (testis), sperm head count (cauda epididymis), sperm motility, 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 offspring:
number and sex of pups, stillbirths, live births, postnatal mortality, presence of gross anomalies, weight gain, physical or behavioral abnormalities, anogenital distance (AGD), presence of nipples/areolae in male pups

GROSS EXAMINATION OF DEAD PUPS:
yes, for external and internal abnormalities; possible cause of death was determined for pups born or found dead

Postmortem examinations (parental animals):

SACRIFICE
- Male animals: All surviving animals of F0 and cohort F1A
- Maternal animals: All surviving animals, F0: post-weaning

GROSS NECROPSY
- Gross necropsy consisted of external and internal examinations including the cervical, thoracic, and abdominal viscera.

HISTOPATHOLOGY
According to table 1 (any other information on materials and methods)

ORGAN WEIGHTS
The following weights were determined in all animals sacrificed on schedule:
1. Anesthetized animals (final body weight)
2. Adrenal glands (fixed)
3. Brain
4. Cauda epididymis
5. Epididymides (left)
6. Heart
7. Kidneys
8. Liver
9. Lymph nodes, axillary (10 animals per sex per group, cohort 1A animals only)
10. Lymph nodes, mesenteric (10 animals per sex per group, cohort 1A animals only)
11. Ovaries
12. Pituitary gland (fixed)
13. Prostate (ventral and dorsolateral part together, fixed)
14. Testes (left)
15. Seminal vesicles including coagulating glands (fixed)
16. Spleen
17. Thymus (fixed)
18. Thyroid glands (with parathyroid glands) (fixed)
19. Uterus with cervix
All paired organs were weighted together (left and right).

The following organs or tissues were fixed in 4% neutral buffered formaldehyde solution or in modified Davidson’s solution:
1. All gross lesions
2. Adrenal glands
3. Bone marrow (femur)
4. Brain
5. Cecum
6. Cervix uteri
7. Coagulating glands
8. Colon
9. Duodenum
10. Epididymis, left (fixed in modified Davidson´s solution)
11. Esophagus
12. Eyes with optic nerve (fixed in modified Davidson’s solution)
13. Heart
14. Ileum
15. Jejunum (with Peyer’s patches)
16. Kidneys
17. Liver
18. Lungs
19. Lymph nodes, axillary
20. Lymph nodes, mesenteric
21. Mammary gland (male and female)
22. Ovaries (fixed in modified Davidson´s solution)
23. Oviducts
24. Pancreas
25. Pituitary gland
26. Prostate
27. Rectum
28. Sciatic nerve
29. Seminal vesicles
30. Skeletal muscle
31. Spinal cord (cervical, thoracic and lumbar cord)
32. Spleen
33. Stomach (forestomach and glandular stomach)
34. Testis, left (fixed in modified Davidson ´s solution)
35. Thymus
36. Thyroid glands (with parathyroid glands)
37. Trachea
38. Urinary bladder
39. Uterus
40. Vagina
41. Vas deferens

- Differential Ovarian Follicle Count (DOFC)in F1 generation: Both ovaries from each female (test groups 10 and 13) were embedded in paraffin blocks.

Postmortem examinations (offspring):

SACRIFICE
- The F1 offspring was sacrificed at PND 4 or PND 22, cohort 1A and 1B animals were dosed for 10 further weeks post-weaning

GROSS NECROPSY
- All cohort 1B animals were sacrificed by decapitation under isoflurane anesthesia.

ORGAN WEIGHTS:
The following weights were determined in all animals sacrificed on schedule:
1. Anesthetized animals (final body weight)
2. Cauda epididymis
3. Epididymides
4. Liver
5. Ovaries
6. Pituitary gland
7. Prostate
8. Testes
9. Seminal vesicles including coagulating gland
10. Uterus (with cervix)

Organ/Tissue fixation
The following organs or tissues were fixed in 4% formaldehyde solution or in modified Davidson’s solution:
1. All gross lesions
2. Adrenal glands
3. Cervix uteri
4. Coagulating glands
5. Epididymides (fixed in modified Davidson ´s solution)
6. Liver
7. Ovaries (fixed in modified Davidson´s solution)
8. Pituitary gland
9. Prostate
10. Seminal vesicles
11. Testes (fixed in modified Davidson ´s solution)
12. Uterus
13. Vagina

HISTOPATHOLOGY:
All organs listed above were preserved in adequate fixative. Histopathological processing and examination by light microscopy was not performed.

Pathological examinations of surplus F1 generation pups on PND 22 were sacrificed and organ weights (anesthetized animals final body weight, brain, spleen, thymus) and organ/tissue fixation (all gross lesions, brainn, mammary gland of male and female, spleen, thymus, thyroid glands) was performed. No histopathology performed.

Statistics:

- Dunnett's test (two-sided): Water consumption, food consumption (parental animals), body weight and body weight change (parental animals and pups; for the pup weights, the litter means were used), estrous cycle duration, number of mating days, duration of gestation, number of implantation sites, postimplantation loss and % postimplantation loss, number of pups delivered per litter, duration of sexual maturation (days to vaginal opening, days to preputial separation), anogenital distance, anogenital index
- Fisher's exact test: Male and female mating indices, male and female fertility indices, gestation index, females with liveborn pups, females with stillborn pups, females with all stillborn pups, live birth index, pups stillborn, pups died, pups cannibalized, pups sacrificed moribund, viability index, lactation index, number of litters with affected pups at necropsy, sexual maturation data (vaginal opening, preputial separation)
- Wilcoxon test: Presence of areolae/nipples, proportions of affected pups per litter with necropsy observations, blood parameter, Urinalysis, Urine pH volume and specific gravity, DOFC, weight parameteres
- Kruskal-Wallis test: Number of cycles and cycle length, blood parameter, Urine pH volume and specific gravity, Spermanalysis, weight parameters

Reproductive indices:

Male mating index, Male fertility index, female mating index, female fertility index, gestation index, live birth index, postimplantation loss

Offspring viability indices:

Viability index, Lactation ondex, sex ratio, anogenital index

Clinical signs:

no effects observed

Description (incidence and severity):

Two females (Nos. 118 and 121 - 0 ppm) of the control, two females (Nos. 130 and 147 - 1250 ppm) of test group 01 and one female (No. 169 - 3750 ppm) of test group 02 did not deliver F1 pups.

Dermal irritation (if dermal study):

not examined

Mortality:

no mortality observed

Body weight and weight changes:

effects observed, treatment-related

Description (incidence and severity):

12500 ppm: In males, body weights were below control values from premating day 28 onwards until the end of the study, most of the time the difference was statistically significant. The average final inlife weight of these males was 7% below control. Accordingly, body weight gain was reduced.

Food consumption and compound intake (if feeding study):

effects observed, non-treatment-related

Description (incidence and severity):

A temporary reduction of food consumption of the high-dose F0 females during premating days 0 - 7 (about 6%) was considered to be a marginal change which had no impact on the overall food consumption or body weight gain of these females. Thus, it was considered to be of no toxicological relevance.

Food efficiency:

not examined

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

no effects observed

Ophthalmological findings:

not examined

Haematological findings:

no effects observed

Clinical biochemistry findings:

no effects observed

Description (incidence and severity):

In parental males and females (test groups 1, 2 and 3; 1250, 3750 and 12500 ppm) no treatment-related alterations of T4 and TSH levels were observed.

Urinalysis findings:

no effects observed

Behaviour (functional findings):

no effects observed

Description (incidence and severity):

No changes of general behavior, which may be attributed to the test substance, were detected in any of the male and female F0 parental animals in any of the groups.

Immunological findings:

not examined

Organ weight findings including organ / body weight ratios:

effects observed, non-treatment-related

Histopathological findings: non-neoplastic:

no effects observed

Histopathological findings: neoplastic:

no effects observed

Reproductive function: oestrous cycle:

no effects observed

Reproductive function: sperm measures:

no effects observed

Reproductive performance:

no effects observed

Description (incidence and severity):

- Male mating index: control, 1250, 3750, 12500 ppm were 96%, 96%, 100% and 100%, resp.
- Male fertility index: ranged between 92% and 100%, no effects observed
- Female mating index: control, 1250, 3750, 12500 ppm were 96%, 96%, 100% and 100%, resp.
- Female fertility index: ranged between 96% and 100%, no effects observed
- Gestation index: 100% in all test groups
- Implantation: not affected
- No indications for test substance-induced intrauterine embryo-/fetolethality since the postimplantation loss did not show any statistically significant differences

Dose descriptor:

NOAEL

Effect level:

405 mg/kg bw/day

Based on:

test mat.

Sex:

male

Basis for effect level:

body weight and weight gain

Dose descriptor:

NOAEL

Effect level:

1 521 mg/kg bw/day

Based on:

test mat.

Sex:

female

Basis for effect level:

other: no adverse effects

Dose descriptor:

NOAEL

Effect level:

12 500 ppm

Based on:

test mat.

Sex:

male/female

Basis for effect level:

reproductive performance

Remarks on result:

other:

Remarks:

about 1221 mg/kg bw/d in males and 1521 mg/kg bw/d in females),

Critical effects observed:

no

Clinical signs:

no effects observed

Dermal irritation (if dermal study):

not examined

Mortality / viability:

no mortality observed

Description (incidence and severity):

F1 PUPS
- Live birth index: 100% in all test groups
- Viability index: 99%, 98%, 100%, 99% in control, 1250, 3750, 12500 ppm

COHORTS
F1A, F1B: no mortalities

Body weight and weight changes:

effects observed, non-treatment-related

Description (incidence and severity):

F1 PUPS
- no effects observed

COHORTS
- F1A: The statistically significantly decreased body weight change in the low-dose male animals during study days 35 - 42 was considered to be spontaneous in nature.
- F1B: The body weights of the high-dose males were statistically significantly below the control values on study day 14 (about 6%) and the body weight change was statistically significantly below the control values during study days 7 - 14 (about 13%). This temporary decrease had no impact on the overall body weight gain of these males. Thus, it was considered to be of no toxicological relevance.

Food consumption and compound intake (if feeding study):

effects observed, non-treatment-related

Description (incidence and severity):

COHORTS
- F1A: In males of the 12500 ppm group, food consumption statistically significantly below control values during study days 35-42 (about 9%). This temporary decrease had no impact on the overall food consumption or body weight gain of these males. Thus, it was considered to be of no toxicological relevance.
- F1B: no effects observed

Food efficiency:

not examined

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

effects observed, non-treatment-related

Description (incidence and severity):

COHORTS
- F1A: The statistically significantly increased water consumption in the low- and mid-dose female animals during several parts of the study was considered to be spontaneous in nature.
- F1B: Water consumption of the high-dose males was statistically significantly below the concurrent control values during study days 10 - 14 (about 22%).

Ophthalmological findings:

not examined

Haematological findings:

effects observed, non-treatment-related

Description (incidence and severity):

F1 PUPS: In females of 1250 ppm, relative eosinophil cell counts were significantly increased, but this change was not dose-dependent. Therefore, this alteration was regarded as incidental and not treatment-related.

Clinical biochemistry findings:

effects observed, non-treatment-related

Description (incidence and severity):

F1 PUPS: In males of 1250 and 12500 ppm, triglyceride values were significantly decreased. The change in test group 11 was not dose-dependent. The values in 12500 ppm group were within the historical control range (males, triglycerides 0.61-1.37 mmol/L). In females of group 3750 ppm, urea levels were significantly decreased, but the values were not dose-dependently altered. Therefore, these changes were regarded as incidental and not treatment-related.
At PND22, in males of group 3750 ppm, T4 values were significantly increased, but the change was not dose-dependent. Therefore, this change was regarded as incidental and not treatment-related.
COHORTS
- In all males and females of the F1A cohort, no treatment-related alterations of T4 and TSH levels were observed.

Urinalysis findings:

effects observed, non-treatment-related

Description (incidence and severity):

F1 PUPS: no effects observed.
F1B: In females of test group 1250 ppm urine volume was significantly increased and specific gravity of the urine was decreased (not statistically significantly). In males of test group 3750 ppm urine pH values were significantly increased. These alterations were not dose- dependent and therefore they were regarded as incidental and not treatment-related.

Sexual maturation:

effects observed, non-treatment-related

Description (incidence and severity):

F1 PUPS: Incidental entry of test group 12500 ppm into female puberty (small average difference to the control of about one day, apparent delay was solely due to 4 high-dose individuals entering puberty after the age of 36 days). Preputial separation comparable across all test groups.

Anogenital distance (AGD):

no effects observed

Description (incidence and severity):

F1 PUPS: no effects observed. Anogenital index comparable to control

Nipple retention in male pups:

no effects observed

Description (incidence and severity):

F1 PUPS: no effects observed

Organ weight findings including organ / body weight ratios:

effects observed, non-treatment-related

Description (incidence and severity):

F1 PUPS
- F1 weanlings not selected for cohorts on PND 22: no effects

COHORTS
- F1A: When compared the control group (set to 100%) with test groups 1250, 3750 and 12500 ppm, the mean absolute weights of the thymus of female animals were significantly changed (86%, 89% and 87%).
When compared the test control group (set to 100%) with test groups 1250, 3750 and 12500 ppm the mean relative weights of the liver and thymus were significantly changed (statistically significant changes with an asterisk):
Liver (male animals): 95%*, 96%* and 96%*
Thymus (female animals): 86%**, 89%, and 87%*
The relative liver weight in males was within historical control values. The weight of the thymus in the control group was clearly above the historical control data, what led to the statistical significances. There was no dose-response relationship and the absolute thymus weight of females was within historical contral data. Therefore, these weight changes were regarded to be incidental and unrelated to treatment.
- F1B: The decrease of the absolute weight of the seminal vesicles was the only parameter changed. The relative weight was not significantly changed. It was therefore not regarded to be a treatment-related effect. Furthermore, the seminal vesicle weight of the F1 generation cohort 1A animals (0.863 g) was in a similar range as the weight in cohort 1B animals (0.85 g).

Gross pathological findings:

effects observed, non-treatment-related

Description (incidence and severity):

F1 PUPS
- F1 pups on PND 4: A few pups showed spontaneous findings, such as post mortem autolysis, hematoma, diaphragmatic hernia, hydronephrosis, dilated renal pelvis and hydroureter. These findings occurred without any relation to dosing and/or can be found in the historical control data at comparable or higher incidences
- F1 weanlings not selected for cohorts on PND 22: no effects

COHORTS
F1A and F1B: no effects

Histopathological findings:

no effects observed

Description (incidence and severity):

F1 PUPS
- F1 weanlings not selected for cohorts on PND 22: not conducted

COHORTS
- F1A: no effects
- F1B: not conducted

Other effects:

no effects observed

Description (incidence and severity):

F1 PUPS
- Number of pups per dam, rates of liveborn, stillborn and dead pups were evenly distributed
- Lactation index: 99%, 99%, 100%, and 99% in control, 1250, 3750, 12500 ppm
- Sex ratio not affected

COHORTS
- Differential ovarian follicle count in F1A revealed no significant differences
- F1A and F1B: no effects on estrous cycle
- F1A: no effects on sperm measures

Behaviour (functional findings):

not examined

Developmental immunotoxicity:

not examined

Dose descriptor:

NOAEL

Generation:

F1

Effect level:

12 500 ppm

Based on:

test mat.

Sex:

male/female

Basis for effect level:

other: developmental toxicity no adverse effects

Remarks on result:

other:

Remarks:

about 1221 mg/kg bw/d in males and 1521 mg/kg bw/d in females),

Dose descriptor:

NOAEL

Generation:

F1 (cohort 1A)

Effect level:

12 500 ppm

Based on:

test mat.

Sex:

male/female

Basis for effect level:

other: general systemic toxicity no adverse effects

Remarks on result:

other:

Remarks:

about 1221 mg/kg bw/d in males and 1521 mg/kg bw/d in females),

Dose descriptor:

NOAEL

Generation:

F1 (cohort 1B)

Effect level:

12 500 ppm

Based on:

test mat.

Sex:

male/female

Basis for effect level:

other: general systemic toxicity no adverse effects

Remarks on result:

other:

Remarks:

about 1221 mg/kg bw/d in males and 1521 mg/kg bw/d in females),

Critical effects observed:

no

Reproductive effects observed:

no

Intake of test substance Cohort F1A

 

	Test group 11 (1000 ppm)	Test group 12 (4000 ppm)	Test group 13 (12500 ppm)
Males	154.4 (102.5 / 276.5)	464.2 (319.9 / 840.0)	1500.9 (965.8 / 2575.1)
Females	186.2 (159.0 / 285.0)	580.7 (505.0 / 865.2)	1668.8 (1305.4 / 2563.2)

 

Intake of the test substance Cohort F1B

 

	Test group 11 (1250 ppm)	Test group 12 (3750 ppm)	Test group 13 (12500 ppm)
Males	161.3 (115.4 / 286.1)	495.4 (352.8 / 881.1)	1415.6 (952.8 / 2473.4)
Females	184.4 (157.0 / 282.5)	583.2 (496.9 / 870.0)	1676.2 (1385.8 / 2516.7)

 

Intake of test substance F0 parental animals

 

	Test group 01 (1250/625 ppm)	Test group 02 (3750/1875 ppm)	Test group 03 (12500/6250 ppm)
F0 males (premating) F0 males (mating and postmating)	126.3 (86.4 / 144.6) 80.8 (69.9 / 100.1)	407.1 (264.1 /440.0) 249.6 (227.4 /296.0)	1187.5 (778.3 / 1338.7) 778.7 (711.3 / 911.6)
F0 females (premating)	156.8 (131.2 / 223.1)	564.9 (455.8 / 826.6)	1571.0 (1295.0 / 2106.8)
F0 females - gestation period - lactation period	127.0 (100.9 / 161.9) 138.7 (86.4 / 207.0)	444.7 (367.3 /531.2) 427.9 (258.1 /677.3)	1282.7 (1021.0 / 1582.3) 1404.2 (893.6 / 2031.5)

 

Conclusions:

Thus, under the conditions of the present extended one-generation reproduction toxicity study the NOAEL (no observed adverse effect level) for general, systemic toxicity is 3750 ppm (about 405 mg/kg bw/d) in the F0 parental males, based on decreased body weight/body weight gain at 12500 ppm. In the F0 parental females as well as adolescent and adult F1 offspring this NOAEL is 12500 ppm (about 1221 mg/kg bw/d in males and 1521 mg/kg bw/d in females). The NOAEL for fertility and reproductive performance for the parental rats is 12500 ppm (about 1221 mg/kg bw/d in males and 1521 mg/kg bw/d in females), the highest tested dose. The NOAEL for developmental toxicity in the F1 progeny is 12500 ppm (about 1221 mg/kg bw/d in males and 1521 mg/kg bw/d in females).

Executive summary:

The test substance was administered to groups of 25 male and 25 female healthy young Wistar rats for test groups 00 - 03 as a solution in drinking water of different concentrations (0, 1250, 3750 and 12500 ppm). F0 animals were treated at least for 10 weeks prior to mating to produce a litter (F1 generation). Mating pairs were from the same dose group. Pups of the F1 litter were selected (F1 rearing animals) and assigned to 2 different cohorts which were subjected to specific postweaning examinations. The study was terminated by the terminal sacrifice of the F1 rearing animals of cohort 1B. Test drinking water containing the test substance was offered continuously throughout the study.

The following test substance-related adverse effects/findings were noted:

12500 ppm

F0 PARENTAL ANIMALS (11R278M0/F0/L1)

CLINICAL EXAMINATIONS/ REPRODUCTIVE PERFORMANCE/ CLINICAL PATHOLOGY/PATHOLOGY

• Decreased body weights in the males from premating day 28 onwards until the end of the study, average final inlife weight 7% below control, decreased body weight gain during pre-mating (9% below control)

F1 PUPS (11R278L1)

CLINICAL EXAMINATIONS/ SEXUAL MATURATION/ GROSS FINDINGS

• No test substance-related adverse findings

F1 REARING ANIMALS, COHORT 1A (11R2781A)

CLINICAL EXAMINATIONS/ CLINICAL PATHOLOGY/ PATHOLOGY

• No test substance-related adverse findings

F1 REARING ANIMALS, COHORT 1B (11R2781B)

CLINICAL EXAMINATIONS/ CLINICAL PATHOLOGY/ PATHOLOGY

• No test substance-related adverse findings

3750 ppm

F0 PARENTAL ANIMALS (11R278M0/F0/L1)

CLINICAL EXAMINATIONS/ REPRODUCTIVE PERFORMANCE/ CLINICAL PATHOLOGY/

PATHOLOGY

• No test substance-related adverse findings

F1 PUPS (11R278L1)

CLINICAL EXAMINATIONS/ SEXUAL MATURATION/ GROSS FINDINGS

• No test substance-related adverse findings

F1 REARING ANIMALS, COHORT 1A (11R2781A)

CLINICAL EXAMINATIONS/ CLINICAL PATHOLOGY/ PATHOLOGY

• No test substance-related adverse findings

F1 REARING ANIMALS, COHORT 1B (11R2781B)

CLINICAL EXAMINATIONS/ CLINICAL PATHOLOGY/ PATHOLOGY

• No test substance-related adverse findings

1250 ppm

F0 PARENTAL ANIMALS (11R278M0/F0/L1)

CLINICAL EXAMINATIONS/ REPRODUCTIVE PERFORMANCE/ CLINICAL PATHOLOGY/

PATHOLOGY

• No test substance-related adverse findings

F1 PUPS (11R278L1)

CLINICAL EXAMINATIONS/ SEXUAL MATURATION/ GROSS FINDINGS

• No test substance-related adverse findings

F1 REARING ANIMALS, COHORT 1A (11R2781A)

CLINICAL EXAMINATIONS/ CLINICAL PATHOLOGY/ PATHOLOGY

• No test substance-related adverse findings

F1 REARING ANIMALS, COHORT 1B (11R2781B)

CLINICAL EXAMINATIONS/ CLINICAL PATHOLOGY/ PATHOLOGY

• No test substance-related adverse findings

The NOAEL (general toxicity) was considered to be 3750 ppm, NOAEL (fertility and reproduction) was 12500 ppm and the NOAEL (developmental) was 12500 ppm.

Effect on fertility: via oral route

Endpoint conclusion:

no adverse effect observed

Dose descriptor:

NOAEL

1 000 mg/kg bw/day

Study duration:

subchronic

Species:

rat

Quality of whole database:

Several data were used in a weight of evidence approach for the assessment of reproductive toxicity. The whole database was considered reliable and sufficient for assessment.

Effect on fertility: via inhalation route

Endpoint conclusion:

no study available

Effect on fertility: via dermal route

Endpoint conclusion:

no study available

Additional information

Toxicity to reproduction

The category member and read across substance3-methylbutan-1-ol was tested in a modified extended one-generation study according to OECD 443 and in compliance with GLP regulations. The potential of the test substance to cause adverse effects on the reproductive system of rodents was investigated to eliminate remaining uncertainties (BASF 2020).

The test substance was administered continuously to groups of 25 male and female Wistar rats in drinking water of different concentrations (0, 1250, 3750 and 12500 ppm). Pups of the F1 litter were selected and assigned to 2 different cohorts. There were no test substance-related mortalities, adverse clinical observations or effects on food consumption in any of the groups. Body weights and body weight change of low and mid-dose F0 males and females, as well as all male and female F1 rats, were not affected by treatment.The body weights of the high-dose F0 males were below the concurrent control values from premating day 28 onwards until the end of the study, most of the time the difference was statistically significant. The average final in-life weight of these males was 7% below control. Accordingly, body weight gain was decreased compared to control during premating days 0 - 7 and 0 - 70 (about 8% and 9%, respectively). It was suggested that it was treatment-related and was considered as a sign of an adverse systemic effect. Regarding clinical pathology, pathology, organ weights, macroscopy, microscopy, and differential ovarian follicle count no treatment-related adverse findings were noted. No effects on fertility, reproductive performance, and developmental toxicity were reported.A statistically significant delay in vaginal opening of about one day beyond the concurrent control was observed in the female F1 offspring of the high-dose group (12500 ppm). The delay is also slightly (less than a day) beyond the historical control range of the test facility. However, pubertal age in test groups 01 (1250 ppm) and 02 (3750 ppm) as well as in concurrent control were all above the upper limit of the historical range, while the statistically significantly higher value in test group 03 (12500 ppm) was again only slightly above concurrent control. This apparent delay was solely due to 4 high-dose individuals entering puberty after the age of 36 days. This and the still rather small average difference to the control of about one day indicates that the later onset of puberty in test group 03 is not a specific effect on the timing of puberty. In addition, none of the other endocrine-sensitive parameters like anogenital distance, or estrous cyclicity in the F1A and B offspring brought beyond puberty, or the integrity of sexual organs in these females including differential ovarian follicle count, indicated any effect of the test item. Thus, the apparently later entry of test group 03 into female puberty is likely to be incidental.Thus, the NOAEL for general, systemic toxicity is 3750 ppm (about 405 mg/kg bw/d) and 12500 ppm (about 1221 mg/kg bw/d in males and 1521 mg/kg bw/d in females) in F0 parental males and in F0 parental females as well as adolescent and adult F1 offspring, respectively. The NOAEL for fertility and reproductive performance for parental rats and developmental toxicity for F1 progeny is 12500 ppm, the highest tested dose.

In addition 3-methylbutan-1-ol was tested in two Combined 28-Day Repeated Dose Toxicity Studies with the Reproduction/Developmental Toxicity Screening Test according to OECD TG 422 and in compliance with GLP regulations (Kuraray Co. Ltd. 2008 and BASF 2018). In the older study the substance was administered to male and female Sprague-Dawley strain SPF rats by gavage at dose levels of 0 (control group), 30, 100 or 300 mg/kg bw for a total of 42 days to males (for 14 days before mating throughout the mating period up to the day before necropsy) and for a total of 41 to 53 days to females (for 14 days before mating throughout the mating and gestation periods up to day 4 of lactation) to examine its repeated dose toxicity and reproductive and developmental toxicity. For the males and females in the 0 and 300 mg/kg bw/day groups, a 14-day recovery period was provided after administration for 42 days to examine reversibility of the toxic changes. The females in the recovery group were not subjected to mating. There were no test article-related effects on estrous cycle, number of days until copulation, copulation index, insemination index, or fertility index. There were no test article-related effects on delivery index, length of gestation period, number of corpora lutea, number of implantation sites, implantation index, index of pre-implantation loss, index of post-implantation loss, index of stillborn pups, parturition index, number of liveborn pups, live birth index or sex ratio, and there were no abnormalities in the lactation condition during the lactation period. In live born pups, there were no test article-related changes in body weight, external observation, gross pathological findings or viability index on day 4 of lactation. Based on the results described above, it was judged that the no adverse effect levels for reproductive and developmental toxicity in male and female parent animals and pups were the highest tested dose of 300 mg/kg bw/day.

To resolve remaining uncertainities about the read-across substances' (3 -methyl-1-butanol) toxicity up to limit doses, in the more recently performed GLP-compliant OECD 422 study, the test item was administered daily as addition to the drinking water in different concentrations to groups of 10 male and 10 female Wistar rats to screen for potential systemic, reproductive and developmental toxicity with doses up to 1000 mg/kg bw (limit dose). After a two-week premating period, these parental animals were paired and the females were allowed to give birth and bring up the offspring until sacrifice on PND 4 or PND 13. In males the overall mean dose of the test substance throughout the study was approx. 71 mg/kg body weight/day (mg/kg bw/d) in the 1250 ppm group, approx. 229 mg/kg bw/d in the 3750 ppm group and approx. 785 mg/kg bw/d in the 12500 ppm group; in females it was approx. 116 mg/kg body weight/day (mg/kg bw/d) in the 1250 ppm group, approx. 359 mg/kg bw/d in the 3750 ppm group and approx. 1273 mg/kg bw/d in the 12500 ppm group. In the clinical examinations of the F0 parental animals no clinical symptoms were caused by the test compound up to the high-concentration of 12500 ppm. In the in-depth investigations including the detailed clinical observation, the functional observational battery and the measurement of motor activity no treatment-related differences to control were observed at any concentration. Water consumption, food consumption and body weights / body weight gain did not show important test substance-related changes. Concerning clinical pathology (including thyroid hormone measurement) no treatment-related, adverse effects were observed up to a concentration of the compound of 12500 ppm in the drinking water. Regarding pathology, there were no treatment-related organ weight changes, gross lesions, and histopathological findings in male and female Wistar rats. Regarding fertility and reproductive performance, as well as pre-postnatal development no signs of toxicity were observed in male or female parental animals or their offspring of all test groups (1250, 3750, and 12500 ppm) during the entire study. Most F0 parental animals across all test groups proved to be fertile and those individuals failing to generate offspring did not show any specific gross or histopathological findings. Mating behavior, conception, implantation and parturition were not influenced. Pups showed normal development up to scheduled sacrifice. Neither determination of anogenital distance/index not the count of nipple/areola anlagen revealed any treatment-related changes up to and including a concentration of the test item of 12500 ppm in the drinking water.

In another GLP-compliant OECD 422 study (BASF 2018), reaction mass of 2-methylbutan-1-ol and pentan-1-ol (EC 903 -139 -3) was administered daily as addition to the drinking water in different concentrations to groups of 10 male and 10 female Wistar rats to screen for potential systemic, reproductive and developmental toxicity. After a two-week premating period, these parental animals were paired and the females were allowed to give birth and bring up the offspring until sacrifice on PND 4 or PND 13. In males the overall mean dose of the test substance throughout the study was approx. 77 mg/kg body weight/day (mg/kg bw/d) in the 1250 ppm group, approx. 254 mg/kg bw/d in the 3750 ppm group and approx. 842 mg/kg bw/d in the 12500 ppm group; in females it was approx. 117 mg/kg body weight/day (mg/kg bw/d) in the 1250 ppm group, approx. 372 mg/kg bw/d in the 3750 ppm group and approx. 1239 mg/kg bw/d in the 12500 ppm group. In the clinical examinations of the F0 parental animals no clinical symptoms were caused by the test compound up to the high-concentration of 12500 ppm. In the in-depth investigations including the detailed clinical observation, the functional observational battery and the measurement of motor activity no treatment-related differences to control were observed at any concentration. Water consumption, food consumption and body weights / body weight gain did not show important test substance-related changes. A small decrease in food consumption of high-dose males as well as temporary increase of water consumption in high-dose females were not accompanied by any body weight changes or other clinical findings and thus not noteworthy enough to be considered adverse. Concerning clinical pathology (including thyroid hormone measurement) no treatment-related, adverse effects were observed up to a concentration of the compound of 12500 ppm in the drinking water. Regarding pathology, there were no treatment-related organ weight changes, gross lesions, and histopathological findings in male and female Wistar rats. Regarding fertility and reproductive performance, as well as pre-postnatal development no signs of toxicity were observed in male or female parental animals or their offspring of all test groups (1250, 3750, and 12500 ppm) during the entire study. Most F0 parental animals across all test groups proved to be fertile and those individuals failing to generate offspring did not show any specific gross or histopathological findings. There were no test article-related effects on estrous cycle, number of days until copulation, copulation index, insemination index, or fertility index. There were no test article-related effects on delivery index, length of gestation period, number of corpora lutea, number of implantation sites, implantation index, index of pre-implantation loss, index of post-implantation loss, index of stillborn pups, parturition index, number of liveborn pups, live birth index or sex ratio, and there were no abnormalities in the lactation condition during the lactation period. In live born pups, there were no test article-related changes in body weight, external observation, gross pathological findings or viability index on day 4 of lactation. Neither determination of anogenital distance/index not the count of nipple/areola anlagen revealed any treatment-related changes up to and including a concentration of the test item of 12500 ppm in the drinking water. This results in a calculated NOAEL of 1000 mg/kg bw for the assessment of adverse effects on reproduction at the screening level.

This assessment is supported by a publication describing a subchronic study performed with pentan-1-ol and a study report of a subchronic study conducted with 3-methylbutan-1-ol:

In a subchronic repeated dose toxicity study conducted equivalent to OECD guideline 408, 15 ASH/CSE rats per sex and dose received doses of 50, 150, 1000 mg/kg bw/day pentan-1-ol in corn oil by gavage for 13 weeks (Butterworth et al. 1978). At necropsy all tissues were examined for gross abnormalities including the reproductive organs. No abnormalities in the reproductive organs were found by histological analysis. Therefore, the highest dose of 1000 mg/kg bw can be seen as the NOAEL regarding reproductive toxicity of pentan-1-ol.

 

In addition, repeated dose toxicity was investigated in a 90 day drinking water study performed according to OECD guideline 408 with 3-methylbutan-1-ol (BG-Chemie 1990). Ten Wistar rats per sex and dose received nominal doses of 80, 340, 1250 mg/kg bw /day 3-methylbutan-1-ol in the drinking water for 3 months. At the end of the 3-month administration period all animals were sacrificed by decapitation and were assessed by gross pathology. Subsequently, a histopathological examination was carried out including the reproductive organs. Regarding toxicity to reproductive organs, no abnormalities were found by histological analysis. Thus, the highest dose level tested, 1250 mg/kg bw /day, was the NOAEL under the conditions of the study.

  

Taken together, there are no hints for a reproductive toxic potential of pentan-1 -ol, nor was any relevant systemic toxicity observed up to at least 1000 mg/kg subchronic exposure. The available experimental data are sufficient to assess the potential toxicity to reproduction by pentan-1-ol. No additional information nor a lower NOAEL would be expected from an extended one-generation study.

A detailled read across justification is attached in IUCLID chapter 13. 

Short description of key information:
Toxicity to reproduction (fertility):
- oral: NOAEL = 1000 mg/kg bw /day (Sprague-Dawley rat, OECD TG 443, drinking water, Read across to CAS No. 123-51-3)

Effects on developmental toxicity

Description of key information

Toxicity to reproduction (development):
- inhalative: NOAEC = 14 mg/L air (maternal and developmental) = sat. vapour conc. (Sprague-Dawley rat, vapour inhalation, GD 1-19)
- inhalative: NOAEC = 10mg/L air (developmental toxicity) = sat. vapour conc. (rat and rabbit, OECD 414)
     

Link to relevant study records

Reference

Reference 1

Endpoint:

developmental toxicity

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

Principles of method if other than guideline:

Developmental study, where rats were exposed on gestation days 1-19

GLP compliance:

no

Limit test:

yes

Species:

rat

Strain:

Sprague-Dawley

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Source: Charles River Breeding Laboratories, Portage, MI, USA
- Weight at study initiation: 200 - 300 g
- Housing: in standard metal cages equipped with automatic water dispensers
- Diet (e.g. ad libitum): NIH-07 lab chow (Ziegler Bros., Garden, MA); ad libitum
- Water (e.g. ad libitum): tap water, ad libitum


ENVIRONMENTAL CONDITIONS
- Temperature (°C): 20 - 24
- Humidity (%): 40 - 60
- 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: Hinners-type chamber
- Method of holding animals in test chamber: in stainless steel wire mesh cages within the exposure chambers
- System of generating particulates/aerosols: A constant flow of test substance was mixed with a known volume of heated compressed air, resulting in instantaneous vaporization of the alcohol. This vapor-air mixture was introduced into the mainstream of the chamber airflow upstream from an orifice, and the resulting turbulence produced uniform mixing of the test chemical throughout the exposure chamber
- Temperature, humidity, pressure in air chamber: temperature of 25 ± 2°C; relative humidity of 50 ± 15%
- Air flow rate: ca. 0.5 m3/minute


TEST ATMOSPHERE
- Brief description of analytical method used: using a Miran 1A infrared-Analyzer at every hour
- Samples taken from breathing zone: no

Analytical verification of doses or concentrations:

yes

Details on analytical verification of doses or concentrations:

Charcoal tube samples were drawn 2 days/week and analyzed by gas chromatography with partial verification of these methods using spiked samples of known concentration.
Means from the continuous monitoring were equal to the target value of 14 mg/L, with standard deviations not exceeding 5% of the means. Concentrations from the secondary monitoring method (gas chromatograph analysis of samples captured on charcoal tubes) were frequently 10-20% lower than the means from the primary method. However, results from spiked samples were often similarly below the concentrations supplied. Consequently, the figures from the primary monitoring method (infrared analyzer) are cited.

Details on mating procedure:

- Impregnation procedure: cohoused
- If cohoused:
- M/F ratio per cage: no data
- Length of cohabitation: no data
- Proof of pregnancy: sperm in vaginal smear referred to as day 0 of pregnancy

Duration of treatment / exposure:

days 1 - 19 of gestation

Frequency of treatment:

7 h/day

Duration of test:

20 d

Remarks:

Doses / Concentrations:
14 mg/L
Basis:
nominal conc.
highest concentration technically achievable

No. of animals per sex per dose:

15

Control animals:

yes, sham-exposed

Maternal examinations:

CAGE SIDE OBSERVATIONS: No data



DETAILED CLINICAL OBSERVATIONS: No data


BODY WEIGHT: Yes
- Time schedule for examinations: weighed daily for the first week and weekly thereafter


FOOD CONSUMPTION: Yes
- Food consumption for each animal determined and mean daily diet consumption calculated as g food/kg body weight/day: No


WATER CONSUMPTION: Yes
- Time schedule for examinations: on gestation days 7, 14, 20


POST-MORTEM EXAMINATIONS: Yes
- Sacrifice on gestation day # 20
- Organs examined: uterus with ovaries

Ovaries and uterine content:

The ovaries and uterine content was examined after termination: Yes
Examinations included:
- Gravid uterus weight: No
- 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:

Data were analyzed using multivariate analysis of variance (MANOVA) and analysis of variance (ANOVA); p< 0.05 was accepted as statistically significant. Three separate analyses were performed using exposure group as the independent variable. For the litter data (numbers of corpora lutea, resorptions, females per litter and males per litter, and weight of females per litter and of males per litter), a one-way ANOVA/ANOVA design was used. If a significant MANOVA was observed, individual ANOVAs were performed, and if these were significant, Bonferroni corrections were made comparing the individual exposure group with controls. A second analysis, for the weight data, used a litter per exposure group X day ANOVA. A third analysis, for the feed and water consumption data, used a litter per exposure group X week MANOVA/ANOVA design. For the ANOVAs, the probabilities of all within-litter main effects and interactions were corrected with the Greenhouse-Geisser estimate of Box's epsilon.

Details on maternal toxic effects:

Maternal toxic effects:yes

Details on maternal toxic effects:
Comparing to the control group maternal body weights were decreased slightly, but this difference was not statistically significant. Food consumption was decreased, but water consumption unchanged.

Dose descriptor:

NOAEC

Effect level:

14 mg/L air

Basis for effect level:

other: maternal toxicity

Details on embryotoxic / teratogenic effects:

Embryotoxic / teratogenic effects:no effects

Details on embryotoxic / teratogenic effects:
Number of corpea lutea, resorptions, gender ratio and fetal weights were not affected by treatment.
Small, but nonsignificant, reversible delays in ossification of caudal vertebrae, sternum, metacarpals and hindpaw phalanges were reported.
No malformations were observed.

Dose descriptor:

NOAEC

Effect level:

>= 14 mg/L air

Basis for effect level:

other: developmental toxicity: no adverse effects observed

Abnormalities:

not specified

Developmental effects observed:

not specified

Results:

	1-Pentanol	Control
Mean maternal weight (g)
day 0	260 ± 22	243 ± 25
day 7	297 ± 21	262 ± 24
day 14	291 ± 23	291 ± 26
day 20	348 ± 25	354 ± 32
overall gain	88	111
Mean feed consumption (g)
week 1	92 ± 14	108 ± 14
week 2	110 ± 10	124 ± 12
week 3	99 ± 12	118 ± 10
overall mean	100 ± 14	117 ± 13
Mean water intake (g)
week 1	222 ± 33	204 ± 46
week 2	223 ± 43	276 ± 93
week 3	288 ± 45	265 ± 123
overall mean	244 ± 51	248 ± 96
Mean corpora lutea/litter	13 ± 3	14 ± 4
Mean resorptions/litter	0.2	0.4
Mean no. females /litter	7 ± 1	8 ± 2
Mean no. males /litter	5 ± 2	7 ± 2
Mean fetal weight (g)
males	3.11 ± 0.31	3.19 ± 0.2
females	3.32 ± 0.26	3.28 ± 0.27

Reference 2

Endpoint:

developmental toxicity

Type of information:

read-across based on grouping of substances (category approach)

Adequacy of study:

weight of evidence

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Justification for type of information:

For justification of read across please refer to section 13.

Qualifier:

according to guideline

Guideline:

OECD Guideline 414 (Prenatal Developmental Toxicity Study)

GLP compliance:

yes

Remarks:

BASF AG, Department of Toxicology

Limit test:

no

Species:

rat

Strain:

Wistar

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Source: Dr. K. Thomae GmbH, D-7950 Biberach/Riss, FRG). The animals were free from any clinically evident signs prior to the beginning of the study.
- Age at study initiation: ca 11 weeks
- Weight at study initiation: ca 216 g
- Housing: singly in wire cages (type D III of Becker & Co, Castrop-Rauxel, FRG)
- Diet (e.g. ad libitum): KLIBA rat/mouse laboratory diet 24-343-4 10 mm pellets, Klingentalmühle AG, CH-4303 Kaiseraugst, Switzerland; during the exposure-free observation period
- Water (e.g. ad libitum): tap water; during the exposure-free observation period
- Acclimation period: at least 5 days

ENVIRONMENTAL CONDITIONS in fully air-conditioned rooms
- Temperature (°C): 20 - 24
- Humidity (%): 30 - 70
- 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: the animals were exposed singly in wire cages (D III) in glass-steel inhalation chambers (manufacturer: BASF Aktiengesellschaft), Volume Vz 1,100 1 (test group 1, 2 and 3), Volume V 2 1,600 1 (test group 0 and parts of the test groups during the preflow period).
- Method of holding animals in test chamber: whole-body exposure system (glass-steel inhalation chamber) with a volume of about 1.1 m3 (test groups 1 - 3); volume of the inhalation chamber of the control group: 1.6 m3
- Source and rate of air: the test substance was supplied by means of two continuously driven piston pumps (Unita, Braun) in test group 1, a continuously metering pump (Optimat MP) in test group 2, and another continuously metering pump (Desaga) in test group 3 to a vaporizer heated with a circulating thermostat and evaporated. The evaporation temperatures are shown in the following table.

_______________________________________________________________________________
Test group /ml/hour /Evaporation temperature (°C) /Supply air (l/hour) /Exhaust air (l/hour)
-----------------------------------------------------------------------------------------------------------------------
0 /Fresh air /- /30000 /29500
1 /13.7 - 14.3 /50 /21500 /22000
2 /75.6 - 82.8 /60 /21500 /22000
3 /295 - 305 /70 /21500 /22000
_______________________________________________________________________________

A stream of fresh air measured with a rotameter took up the vapors. A further stream of fresh air was passed in downstream of the vaporizer. After passing through a mixing device, this mixture of vapors and air was supplied to exposure system

- Temperature, humidity, pressure in air chamber: the pressure in the inhalation chambers was measured continuously (inclined manometer) and recorded, as a rule, 3 times/exposure. Conditioned supply air ( about 50% humidity, 22 °C) was used for the exposure in all test groups. The temperature in the exposure systems was measured continuously (digital thermometer, Diehl) and recorded, as a rule, 3 times/exposure. The relative humidity in the chambers was checked with a humidity measuring probe (Vaisala) at least once a day and also recorded.
- Air flow rate: all air flows, supply air and exhaust air were adjusted by means of flowmeters (rotameter) for all test groups and recorded, as a rule, 6 times/exposure.

TEST ATMOSPHERE
- Brief description of analytical method used: the concentration in the inhalation chambers was monitored by means of a GC-method. The concentrations of the test groups were analyzed by gas chromatography after absorption of MEB samples in 2-propanol.
The gas chromatographs were calibrated with weighed amounts of the test substance.
- Samples taken from breathing zone: yes

Analytical verification of doses or concentrations:

yes

Details on analytical verification of doses or concentrations:

The concentration in the inhalation chambers was monitored by means of a GC-method.
The concentrations of the test groups were analyzed by gas chromatography after absorption of MEB samples in 2-propanol.
The gas chromatographs were calibrated with weighed amounts of the test substance.

Details on mating procedure:

- Impregnation procedure: cohoused
- If cohoused:
- M/F ratio per cage: 1/4
- Length of cohabitation: 15.5 hours (overnight)
- 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:

days 6 - 15 of gestation

Frequency of treatment:

6 hours/day

Duration of test:

20 days

Remarks:

Doses / Concentrations:
0.51±0.015, 2.50±0.169 and 9.8±0.66 mg/l
Basis:
analytical conc.
gas chromatograph monitoring

Remarks:

Doses / Concentrations:
0.50, 2.50 and 10.0 mg/l
Basis:
nominal conc.
target concentration

No. of animals per sex per dose:

25 (in driplicate in each group)

Control animals:

yes, concurrent no treatment

Details on study design:

- Dose selection rationale: in a pretest no maternal toxic effects could be observed at concentrations up to 5 mg/l, which is the limit test concentration. Because fetotoxic effects were reported with other alcohols at somewhat higher concentrations, the highest concentration selected for the study was 10 mg/l, which is near to the saturated vapor concentration at approx. 20°C (12 - 14 mg/l). In order to determine dose-response relationships, an intermediate (2.5 mg/ml) and a low (0.5 mg/ml) concentration levels were also selected.

Maternal examinations:

CAGE SIDE OBSERVATIONS: Yes

DETAILED CLINICAL OBSERVATIONS: Yes
- Time schedule: the behavior and state of health of the test animals were checked on workdays at least 3 times on exposure days and, as a rule, once during the post-exposure observation period.

BODY WEIGHT: Yes
- Time schedule for examinations: the body weight of the animals was checked on day 0 day of dectection of sperm) and on days 3, 6, 9, 12, 15, 18 and 20 p.c. As a rule, the animals were weighed at the same time of the day. The difference between the body weight on the day of weighing and the body weight on the previous weighing was calculated. Moreover the same was done for 3 different study periods:
* preflow period (day 0- 6 p.c.)
* exposure period (days 6 - 15 p.c.)
* observation period (days 15 - 20 p.c.).
These values are defined as body weight change. Moreover, the corrected body weight gain (body weight on day 20 p.c. minus the body weight on day 6 p.c. minus weight of the uterus before it was opened) was determined after the dams had been sacrificed at the end of the study.

POST-MORTEM EXAMINATIONS: Yes
- Sacrifice: on day 20 p.c. the dams (as well as moribund dams) were sacrificed by cercical dislocation and the fetuses removed by cesarean section. These animals and dams which died intercurrently as well as the contents of uterus from these animals were investigated, if possible in the same way as at terminal sacrifice (exception: uterus weight).
- Organs examined: after the dams had been sacrificed, they were necropsied and assessed by gross pathology. The uterus and the ovaries were removed and the following data were recorded: weight of uterus before it was opened, number of corpora lutea, number and distribution of implantation sites classified as live fetuses or dead implantations: early resorptions (only decidual or placental tissues visible or according to SALEWSKI from uteri from apparently non-pregnant animals and the empty uterus horn in the case of single-horn pregnancy); late resorptions (embryonic or fetal tissue in addition to placental tissue visible); dead fetuses (hypoxemic fetuses which did not breathe spontaneously after the uterus had been opened). Furthermore, calculations of conception rate and pre and postimplantation losses were carried out.

OTHER: a check for dead animals was made daily.

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

Fetal examinations:

- External examinations:Yes: all per litter
- Soft tissue examinations: Yes: all per litter
- Skeletal examinations: Yes: all per litter
- Head examinations: Yes: all per litter

Statistics:

The statistical evaluation of the data was carried out on the computer systems of the Department of Toxicology (Dr. Hoffmann responsible). Examinations of the dams and fetuses Dunnett's Test (8 - 9) was used for statistical evaluation of body weight, body weight change, corrected body weight gain (net maternal body weight change), weight of the uterus before it was opened, weight of fetuses, weight of placentae, corpora lutea, implantations, pre and postimplantation loss, resorptions and live fetuses. Fisher's Exact Test ( 10) was used for statistical evaluation of conception rate, mortality (of the dams) and all fetal findings.
Significances resulting from these tests have been indicated in the tables (a for p < 0.05, b for p < 0.01).

Indices:

- The conception rate (in 3;) was calculated according to the following formula: (number of pregnant animals/ number of fertilized animals)*100
- The preimplantation loss (in %) was calculated according to the following formula: (number of corpora lutea - number of implantations/number of corpora lutea)*100
- The postimplantation loss (in %) was calculated from the following formula: (number of implantations - number of live fetuses/number of implantations)*100

Historical control data:

Historical control studies from Himalayan rabbits carried out in BASF's Department of Toxicology between 1986 and 1990

Details on maternal toxic effects:

Maternal toxic effects:yes

Details on maternal toxic effects:
Only transient impairment in the body weight change of the dams was observed at the beginning of the exposure period (days 6 - 9 p.c.).

Dose descriptor:

NOAEC

Effect level:

2.5 mg/L air (nominal)

Basis for effect level:

other: maternal toxicity

Details on embryotoxic / teratogenic effects:

Embryotoxic / teratogenic effects:no effects

Details on embryotoxic / teratogenic effects:
The fetuses did not show any substance-related effects (neither embryo-/fetotoxic nor teratogenic effects).

Dose descriptor:

NOAEC

Effect level:

10 mg/L air (nominal)

Basis for effect level:

other: teratogenicity

Abnormalities:

not specified

Developmental effects observed:

not specified

1) Examinations of the dams:

- Clinical Examinations:

Only pregnant dams were used for the calculations of mean maternal body weights and body weight change. Only pregnant dams with scheduled sacrifice (day 20 p.c.) were taken for the calculation of mean gravid uterine weights, mean net maternal body weight change (corrected body weight gain) and summary of reproduction data.

In this study 3, 4 and 2 females (respectively in test group 1, 4 and 3) were excluded from the above mentioned calculations since they did not conceive (while one animal died in the test group 2).

*Clinical signs and findings: there were no substance-induced clinical signs or findings in all test groups (0 - 3) at any time of the study period (preflow, exposure, post-exposure observation).

*Lethality: no deaths were recorded throughout the study period in test groups 0, 2 and 3. One animal of test group 1, which was not pregnant, was found dead in cage on day 12 p.c.

 

- Body weight:

The body weights of all animals in test group 1 compared to the control (0) were not statistically significant. In test group 2, the body weight change was statistically significantly increased (p < 0.05) between days 12 -15 p.c. In test group 3, compared to the control (group 0), the body weight change was statistically significantly decreased (p < 0.05) between days 6 -9 p.c. and statistically significantly increased (p < 0.01) between day 12-15 p.c.

Over the total exposure period (days 6-15 p.c.) no substance-related effects were observed. It cannot be decided clearly, whether there was a slight effect on body weight retardation in the first days of exposure (6 - 9 p.c.) followed by an adaptation/recovery phase in the further days of exposure (12 - 15 p.c.) or whether this is an incidental finding. In case this effect may be considered as a very slight indication of maternal toxicity only during the first phase of exposure to a very high concentration of 10 mg/l of test substance.

 

- Body weight change:

The results of the corrected body weight gain (body weight on day 20 p.c. minus body weight on day 6 p.c. minus weight of the uterus before it was opened) do not show any differences of biological relevance between the groups.

 

- Examinations of the dams at termination

*Necropsy findings: there were no substance-related observations at necropsy in any of the dams.

*Uterus weight: the uterus weights of the animals were not influenced by the exposure to the test substance.

*Reproduction data of dams: the conception rate varied between 80 and 100%. There were no substance-related and/or statistically significant differences between the groups in conception rate, in the mean number of corpora lutea and implantation sites or in the values calculated for the pre- and the postimplantation losses, the number of resorptions and viable fetuses. The differences evident are considered to be incidental and within the normal range of deviations for animals of this strain and age (also compared to the lab's historical control data).

 

2) Examinations of the fetuses

- Sex distribution of fetuses:

The sex distribution of the fetuses in test groups 1- 3 (0.5, 2.5 and 10 mg/l) was comparable with the control fetuses (the differences observed in comparison being without any biological relevance).

 

- Weight of placentae:

The mean placental weights in test groups 1-3 (0.5, 2.5 and 10 mg/l) were not influenced by the administration of the test substance to the dams (the differences observed being without any biological relevance).

 

- Weight of fetuses:

The mean fetal weights were not influenced by the test substance exposure (all values are within the range of biological variation (also comparable to the historical control values).

 

- External examination of the fetuses:

The external examination of the fetuses revealed only one malformation (polydactyly) in one fetus out of 326 fetuses in the highest dose group (10 mg/l) and no variations in any group.

So-called unclassified observations were recorded for 4 fetuses of the control group (blood coagulum around placenta), 9 fetuses (from one litter) in test group 2 (2.5 mg/l) (placentae necrobiotic) and 1 fetus of the highest dose group (10 mg/l) (placentae fused).

 

- Soft tissue examinations of the fetuses:

The examination of the organs of the fetuses revealed two malformations in test group 2 (2.5 mg/l). For one fetus a globular shaped heart, for another one dextrocardia was recorded. Variations were detected in all groups. The very common finding (dilated renal pelvis) in the rat strain used in this study occurred without any dose-response relationship. The occurrence of the other variation (hydroureter) did not show any statistically significant difference between the groups. The examination of the organs of the fetuses revealed no so-called unclassified observations (like blood coagulum around the bladder) in any test group.

 

- Skeletal examination of the fetuses:

Various malformations of the sternebrae (sternebra(e) bipartite, ossification centers dislocated, cleft sternum) and/or the vertebral column (e.g. thoracic vertebral body/bodies dumbbell-shaped (asym.) or bipartite (asym.)) were seen in very few fetuses (4 - 8) in all test groups, the differences not being statistically significant. The variations elicited were related to the ribs shortened or missing 13th, accessory 14th ribs or rudimentary cervical ribs) and the sternum (sternebra(e) of irregular shape, bipartite or accessory sternebra) and were found in all groups to about the same extent with the exception of a lower incidence of shortened 13^thrib(s) in the highest dose group.

In all groups signs of retardations (incomplete or missing ossification of hyoid, skull, metacarpal or metatarsal bones, vertebral bodies and/or sternebra(e)) were found without any clear differences of biological relevance between the groups.

 

Reference 3

Endpoint:

developmental toxicity

Type of information:

read-across based on grouping of substances (category approach)

Adequacy of study:

weight of evidence

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Justification for type of information:

For justification of read across please refer to section 13.

Qualifier:

according to guideline

Guideline:

OECD Guideline 414 (Prenatal Developmental Toxicity Study)

GLP compliance:

yes

Remarks:

BASF AG, Department of Toxicology

Limit test:

no

Species:

rabbit

Strain:

Himalayan

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Source: Dr. K. Thomae GmbH facilities, D-7950 Biberach/Riss, FRG); the animals were free from any clinically evident signs prior to the beginning of the study
- Age at study initiation: 24 - 29 weeks
- Weight at study initiation: ca 2.7 kg
- Housing: singly in wire cages (type K 300/8, EBECO, Becker & Co., Castrop-Rauxel, FRG)
- Diet (e.g. ad libitum): KLIBA rabbit laboratory diet 24-341-4 10 mm pellets, Klingentalmühle AG, CH-4303 Kaiseraugst, Switzerland; during the exposure-free observation period
- Water (e.g. ad libitum): tap water; during the exposure-free observation period
- Acclimation period: at least 5 days

ENVIRONMENTAL CONDITIONS
- Temperature (°C): 20 - 24
- Humidity (%): 30 - 70
- 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: the animals were exposed singly in wire cages (D III) in glass-steel inhalation chambers (manufacturer: BASF Aktiengesellschaft), Volume Vz 1,100 1 (test group 1, 2 and 3), Volume V 2 1,600 1 (test group 0 and parts of the test groups during the preflow period).
- Method of holding animals in test chamber: whole-body exposure system (glass-steel inhalation chamber) with a volume of about 1.1 m3 (test groups 1 - 3); volume of the inhalation chamber of the control group: 1.6 m3
- Source and rate of air: the test substance was supplied by means of two continuously driven piston pumps (Unita, Braun) in test
group 1, a continuously metering pump (Optimat MP) in test group 2, and another continuously metering pump (Desaga) in test group 3 to a vaporizer heated with a circulating thermostat and evaporated. The evaporation temperatures are shown in the following table.

_______________________________________________________________________________
Test group /ml/hour /Evaporation temperature (°C) /Supply air (l/hour) /Exhaust air (l/hour)
-----------------------------------------------------------------------------------------------------------------------
0 /Fresh air /- /30000 /29500
1 /13.7 - 14.3 /50 /21500 /22000
2 /75.6 - 82.8 /60 /21500 /22000
3 /295 - 305 /70 /21500 /22000
_______________________________________________________________________________

A stream of fresh air measured with a rotameter took up the vapors. A further stream of fresh air was passed in downstream of the vaporizer. After passing through a mixing device, this mixture of vapors and air was supplied to exposure system

- Temperature, humidity, pressure in air chamber: the pressure in the inhalation chambers was measured continuously (inclined manometer) and recorded, as a rule, 3 times/exposure. Conditioned supply air ( about 50% humidity, 22 °C) was used for the exposure in all test groups. The temperature in the exposure systems was measured continuously (digital thermometer, Diehl) and recorded, as a rule, 3 times/exposure. The relative humidity in the chambers was checked with a humidity measuring probe (Vaisala) at least once a day and also recorded.
- Air flow rate: all air flows, supply air and exhaust air were adjusted by means of flowmeters (rotameter) for all test groups and recorded, as a rule, 6 times/exposure.

TEST ATMOSPHERE
- Brief description of analytical method used: the concentration in the inhalation chambers was monitored by means of a GC-method. The concentrations of the test groups were analyzed by gas chromatography after absorption of MEB samples in 2-propanol.
The gas chromatographs were calibrated with weighed amounts of the test substance.
- Samples taken from breathing zone: yes

Analytical verification of doses or concentrations:

yes

Details on analytical verification of doses or concentrations:

The concentration in the inhalation chambers was monitored by means of a GC-method.
The concentrations of the test groups were analyzed by gas chromatography after absorption of MEB samples in 2-propanol.
The gas chromatographs were calibrated with weighed amounts of the test substance.

Details on mating procedure:

- Impregnation procedure: artificial insemination
- Proof of pregnancy: sperm in vaginal smear referred to as day 0 of pregnancy

Duration of treatment / exposure:

days 7 - 19 of gestation

Frequency of treatment:

6 hours/day

Duration of test:

29 days

Remarks:

Doses / Concentrations:
0.5, 2.5 and 10 mg/l
Basis:
nominal conc.
target concentration

Remarks:

Doses / Concentrations:
0.51 ± 0.014, 2.51 ± 0.150 and 9.8 ± 0.66 mg/l
Basis:
analytical conc.
gas chromatograph monitoring

No. of animals per sex per dose:

15 (in triplicate of 5 animals per group)

Control animals:

yes, concurrent no treatment

Details on study design:

- Dose selection rationale: in a pretest no maternal toxic effects could be observed at concentrations up to 5 mg/l, which is the limit test concentration. Because fetotoxic effects were reported with other alcohols at somewhat higher concentrations, the highest concentration selected for the study was 10 mg/l, which is near to the saturated vapor concentration at approx. 20°C (12 - 14 mg/l). In order to determine dose-response relationships, an intermediate (2.5 mg/ml) and a low (0.5 mg/ml) concentration levels were also selected.

Maternal examinations:

CAGE SIDE OBSERVATIONS: Yes

DETAILED CLINICAL OBSERVATIONS: Yes
- Time schedule: the behavior and state of health of the test animals were checked on workdays at least 3 times on exposure days and, as a rule, once during the post-exposure observation period.

BODY WEIGHT: Yes
- Time schedule for examinations: the difference between the body weight on the day of weighing and the body weight on the day of the previons weighing was calculated as a group mean. The same was done for the 3 different study priods:
* preflow period (day 0- 7 p.i.)
* exposure period (days 7 - 19 p.i.)
* observation period (days 19 - 29 p.i.).
These values are defined as body weight change. Moreover, the corrected body weight gain (body weight on day 29 p.i. minus the body weight on day 7 p.i. minus weight of the uterus before it was opened) was determined after the dams had been sacrificed at the end of the study.

POST-MORTEM EXAMINATIONS: Yes
- Sacrifice: on day 29 p.i. the dams were sacrificed by intravenous injection of a pentobarbital and the fetuses removed by cesarean section.

OTHER: a check for dead animals was made daily.

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

Fetal examinations:

- External examinations:Yes: all per litter
- Soft tissue examinations: Yes: all per litter
- Skeletal examinations: Yes: all per litter
- Head examinations: Yes: all per litter

Statistics:

The statistical evaluation of the data was carried out on the computer systems of the Department of Toxicology. Examinations of the dams and fetuses Dunnett's Test (8 - 9) was used for statistical evaluation of body weight, body weight change, corrected body weight gain (net maternal body weight change), weight of the uterus before it was opened, weight of fetuses, weight of placentae, corpora lutea, implantations, preand postimplantation loss, resorptions and live fetuses. Fisher's Exact Test ( 10) was used for statistical evaluation of conception rate, mortality (of the dams) and all fetal findings.
Significances resulting from these tests have been indicated in the tables (a for p < 0.05, b for p 0.01).

Indices:

- The conception rate (in 3;) was calculated according to the following formula: (number of pregnant animals/ number of fertilized animals)*100
- The preimplantation loss (in %) was calculated according to the following formula: (number of corpora lutea - number of implantations/number of corpora lutea)*100
- The postimplantation loss (in %) was calculated from the following formula: (number of implantations - number of live fetuses/number of implantations)*100

Historical control data:

Historical control studies from Himalayan rabbits carried out in BASF's Department of Toxicology between 1986 and 1990

Details on maternal toxic effects:

Maternal toxic effects:yes

Details on maternal toxic effects:
Maternal toxicity: Slight, statistically significant retardation in body weight gain of the dams of the 10 mg/l group in the exposure period. Indications of irritating effect on dam's eyes during exposure period.

Dose descriptor:

NOAEC

Effect level:

2.5 mg/L air (nominal)

Basis for effect level:

other: maternal toxicity

Details on embryotoxic / teratogenic effects:

Embryotoxic / teratogenic effects:no effects

Details on embryotoxic / teratogenic effects:
The fetuses did not show any substance-related effects (neither embryo-/fetotoxic nor teratogenic effects).

Dose descriptor:

NOAEC

Effect level:

10 mg/L air (nominal)

Basis for effect level:

other: teratogenicity

Abnormalities:

not specified

Developmental effects observed:

not specified

1) Examinations of the dams:

- Clinical Examinations:

Only pregnant dams were used for the calculations of mean maternal body weights and body weight change. Only pregnant dams with scheduled sacrifice (day 29 p.i.) were taken for the calculation of mean gravid uterine weights, mean net maternal body weight change (corrected body weight gain) and summary of reproduction data.

In this study one female (test group 1) was excluded from the above mentioned calculations since she did not conceive.

 

*Clinical signs and findings: there were no substance-induced clinical signs or findings in test groups 0, 1 and 2 at any time of the study period (preflow, exposure, post-exposure observation). The animals of test group 3 showed reddish eyes, eyelid closure and slight, aqueous discharge from eyes after exposure. Towards the end of exposure, these symptoms were also observed before exposure. The animals were free from abnormal clinical signs and findings during preflow and post-exposure observation. One animal showed reduced defecation at the start of the post-exposure observation period.

 

- Body weight:

The body weights of all test groups (1 - 3) compared to the control (0) were not statistically significantly influenced.

 

- Body weight change:

The body weight change of test groups 1 - 2 compared to the control (0) was not statistically significantly influenced. In test group 3 there was a statistically significant retardation of the body weight (p < 0.05) between day 7 - 10 p.i. compared to the control. Over the total exposure period (days 7- 19 p.i.) a slight retardation in body weight increase can be observed. Both findings are indications of a substance related effect, which is more pronounced in the first phase of the exposure period. This is confirmed by a statistically significant higher increase of the body weight in the post-exposure observation period, which can be interpreted as a recovery after end of exposure.

Corrected body weight gain (net maternal body weight change): the results of the corrected body weight gain (body weight on day 29 p.i. minus body weight on day 7 p.i. minus weight of the uterus before it was opened) do not show clearly dose-related differences between the groups.

 

- Examinations of the dams at termination:

*Necropsy findings: all of the findings which were recorded for the does are spontaneous ones (i.e. inflammation in fatty tissue, abscess in kidney, blind ending uterine horn(s)), and are not related to the exposure of the does.

*Uterus weight: the uterus weight of the animals of the substance-treated groups do not show any significant differences in comparison to the controls. The observable differences are in the range of biological variation.

*Reproduction data of dams: the conception rate varied between 93 and 100%. Concerning all groups, there were no substance-related and/or statistically significant differences in the conception rate, in the mean number of corpora lutea and implantation sites or in the values calculated for the pre- and the postimplantation loss, the number of resorptions or viable fetuses. The differences evident are considered to be incidental and within the normal range of deviations for animals of this strain and age.

 

2) Examinations of the fetuses:

 - Sex distribution of fetuses:

The sex distribution in test groups 1-3 (0.5 - 10 mg/l) was comparable with the control group. The observable differences are without any biological relevance.

- Weight of placentae:

The mean placental weights in test groups 1, 2 and 3 (0.5, 2.5 and 10 mg/l) were not influenced by the administration of the test substance to the does. The differences observed in comparison to the control are without any dose-response relationship and without any biological relevance. The marginally reduced mean placental weights in the substance-exposed groups are not related to the test substance exposure, but are caused by the incidentally increased number of live fetuses/doe in these groups in comparison to the controls.

- External examination of the fetuses:

The external examination of the fetuses revealed no malformations and only one type of variation (pseudoankylosis) in one fetus each of test groups 1 and 2 (0.5 and 2.5 mg/l) and 2 fetuses of test group 3 (10 mg/l). This common finding is also present at a comparable incidence in the historical control.

- Soft tissue examinations of the fetuses:

The examination of the organs of the fetuses revealed no malformations in any group.

- Skeletal examination of the fetuses:

Various malformations of the sternum and/or the vertebral column were seen in 3 fetuses of the control and the 0.5 mg/l group and in 5 fetuses of the 2.5 and 10 mg/l group. No other skeletal malformations were recorded for any group.

Effect on developmental toxicity: via oral route

Endpoint conclusion:

no study available

Effect on developmental toxicity: via inhalation route

Endpoint conclusion:

no adverse effect observed

Dose descriptor:

NOAEC

14 000 mg/m³

Study duration:

subacute

Species:

rat

Quality of whole database:

Several data were used in a weight of evidence approach for the assessment of developmental toxicity. The whole database was considered relaible and sufficient for assessment.

Effect on developmental toxicity: via dermal route

Endpoint conclusion:

no study available

Additional information

Developmental toxicity

Developmental toxicity of pentan-1-ol was examined in a study, where 15 female, sperm-positive Sprague-Dawley rats were exposed to a concentration of 14 mg/L air, the highest vapour concentration technically achievable (Nelson et al. 1989). Thereby, the exposure duration was 7 hour/day on days 1 - 19 of gestation. At the end of the exposure period, the dams were sacrificed and ovaries and uterine content as well as fetuses were examined. The number of corpora lutea, implantations, resorption sites, and live fetuses was recorded. One-half of the fetuses were examined for skeletal malformations, while the remaining fetuses were examined for visceral abnormalities. At 14 mg/L air, no overt maternal toxicity was observed. Overall feed consumption was lower than in controls, but water consumption remained unchanged. Although the weight gain was slightly decreased, this effect did not reach statistical significance. The number of corpora lutea, resorptions, gender ratio and fetal weights were also not affected by treatment. Although small reversible delays in ossification of the caudal vertebrae, the sternum, the metacarpals and the hind paw phalanges were reported, these effects were not statistically significant. In addition, no malformations of the fetuses were observed. Thus, the dose of 14 mg/L air can be seen as the NOAEC regarding maternal as well as developmental toxicity of pentan-1-ol.

Developmental toxicity of 3-methylbutan-1-ol was investigated in a prenatal developmental study performed according to OECD test guideline 414. 25 Wistar rats were exposed to test substance vapours at 0.5, 2.5 and 10 mg/L air for 6 hours/day on days 6 - 15 of gestation. The number of corpora lutea, implantations, resorption sites, and live fetuses per sex was recorded. Fetuses were examined for skeletal malformations or visceral abnormalities. As a result, a marginal and transient (days 6-9) retardation of bodyweight gain was observed in the dams of the highest dose group, while the fetuses did not show any embryo-/fetotoxic or teratogenic effects in all dose groups. Thus, the NOAEC was 2.5 mg/L air for maternal toxicity and 10 mg/L air for developmental toxicity, respectively.

In a similar study also performed according to OECD TG 414, Himalayan rabbits as second species were exposed to substance vapours at 0.5, 2.5 and 10 mg/L air, 6 hours/day, on days 7 - 19 of gestation. Animals were sacrificed on gestation day 29. Gravid uterus weight, number of copora lutea, implantation sites, early and late resorptions, and live foetuses were recorded. All foetuses were examined for visceral and skeletal changes, including a head examination. The only effect was a decreased body weight in the high dose animals between gestation days 7 and 10, comparable to the findings in rats. In addition, signs of beginning eye irritation were observed in this group. Thus, the NOAEC was 2.5 mg/L air for maternal toxicity and 10 mg/L air for developmental toxicity in rabbits.

 

Thus, no indications of a developmental toxic or teratogenic effect were seen in animal studies with pentan-1-ol and its structural analogue 3-methylbutan-1-ol. A detailled justification for this read across is attached in IUCLID chapter 13.

Justification for selection of Effect on developmental toxicity: via inhalation route:
most reliable data

Justification for classification or non-classification

The available data are considered reliable and suitable for classification purposes under Regulation (EC) No 1272/2008 (CLP). As a result, there is no reason to classify pentan-1 -ol for toxicity to reproduction or developmental toxicity under Regulation (EC) No 1272/2008, as amended for the seventh time in Regulation No (EC) 1297/2014.