Nonane-1,9-diol

Toxicity to reproduction

Administrative data

Endpoint:

screening for reproductive / developmental toxicity

Type of information:

experimental study

Adequacy of study:

key study

Study period:

1994-10-17 to 1994-12-20

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

guideline study

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

1995

Report date:

1995

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

OECD Guideline 421 (Reproduction / Developmental Toxicity Screening Test)

Version / remarks:

1994

Deviations:

no

Principles of method if other than guideline:

Deficiencies:
The updated OECD 421 (2016) guidance requires evaluation of oestrus cyclicity and sperm parameters were not measured. Developmental observations of pups, in particular nipple retention was not undertaken. Thyroid hormone levels in parental male animals not assessed, and where necessary for parental females and pups. However, the following conclusions can be drawn from existing data to
- reproductive indices in this study from F0 treated animals were comparable to the control group.
- although circulating levels of T4 and TSH were not investigated, thyroid hormone levels have been monitored in the 90 day repeat dose oral toxicity study.
- Up to day 4 p.p, no developmental delays were observed in test article treated animals compared to the control.

Overall it is therefore reasonable to conclude that there is no evidence to suggest that 1,6-hexandiol has any in the developing fetus.

GLP compliance:

yes

Limit test:

no

Test material

Test material information

Constituent 1

Reference substance name:

Hexane-1,6-diol

EC Number:

211-074-0

EC Name:

Hexane-1,6-diol

Cas Number:

629-11-8

Molecular formula:

C6H14O2

IUPAC Name:

hexane-1,6-diol

Specific details on test material used for the study:

SOURCE OF TEST MATERIAL
- Chemical name: 1,6-hexanediol
- CAS no.: 629-11-8
- EC-no.: 211-074-0
- Source and lot/batch No.of test material: BASF / Tank 19
- Molecular weight: 118.175 g/mol
- Purity: 97.0%

Test animals

Species:

rat

Strain:

Wistar

Details on species / strain selection:

refer to details on test animals and environmental conditions

Sex:

male/female

Details on test animals or test system and environmental conditions:

Age: F0: 10-11 weeks
Weight at dosing: F0: M: 369-414; F: 224-248g
Source: Dr. K. THOMAE GmbH, Biberach an der Riss, Germany
Acclimation period: 5 days
Diet: Kliba maintenance diet rat/mouse/hamster GLP 343 meal, ad libitum
Water: Municipal tap water, ad libitum
Housing: individually (except during mating when females and males were housed 1:1)

Environmental conditions
Temperature: 20-24°C
Humidity: 30-70%
Air changes: Not stated
Photoperiod: 12 hours light/dark

Administration / exposure

Route of administration:

oral: gavage

Vehicle:

water

Details on exposure:

Four groups of 10 male and 10 female SD rats forming the F0 generation received the test article by oral gavage at dose levels of 0, 100, 400 or 1000 mg/kg bw/d, employing a dose volume of 10 mL/kg bw once daily. After at least 14 d of treatment, males and females from the same dose group were mated at a ratio of 1:1 (refer to Details on mating procedure for more details).

After this mating period, the male animals were sacrificed. The females were allowed to litter and rear their pups until day 4 after parturition (p.p). Thereafter, the pups and the F0 generation female parental animals were sacrificed.

Details on mating procedure:

Each of the male and female animals were mated overnight at a ratio of 1:1 for a maximum of 2 wks. Matings occurred by placing the female in the cage of the male mating partner from ~4pm through until 7-9am the following morning.

A vaginal smear was prepared after each mating and examined for sperm. If sperm was detected, pairing of the animals was discontinued. The day on which sperm were detected was denoted "day 0" and the following day "day 1" p.c. (post coitum).

Analytical verification of doses or concentrations:

yes

Details on analytical verification of doses or concentrations:

Analytical verifications of the stability of the aqueous test article solutions for a period of at least 4 h at room temperature were carried out in a separate study prior to the beginning of this screening study. Under this separate study, homogeneity asessment was undertaken and confirmed.

Homogenetiy was confirmed twice during the study period for verification of the concentrations .

Dose formulations were prepared daily and dosed within time frame of 4 h (period of which stability was confirmed). As homogeneity was confirmed in a separate study, it was considered sufficient to confirm concurrent homogenity visually.

The concentration control analyses of the aqueous solutions of the test article formulations confirmed yields of 100 % - 103 % of the nominal concentrations.

Duration of treatment / exposure:

Parental males: 28 d
Parental females: 50 days
F1 offspring: day 4 after parturition

Frequency of treatment:

Parental anaimals: single oral gavage administered daily

Details on study schedule:

Refer to details on exposure and details on mating procedure

Doses / concentrations

Doses / concentrations 1

Dose / conc.:

0 mg/kg bw/day (nominal)

Remarks:

(vehilcle distilled water)

Doses / concentrations 2

Dose / conc.:

100 mg/kg bw/day (nominal)

Doses / concentrations 3

Dose / conc.:

400 mg/kg bw/day (nominal)

Doses / concentrations 4

Dose / conc.:

1 000 mg/kg bw/day (nominal)

No. of animals per sex per dose:

10/sex/group

Control animals:

yes, concurrent vehicle

Details on study design:

Refer to details on exposure and details on mating procedure

Examinations

Parental animals: Observations and examinations:

Parental animals of both sexes were observed for clinical signs and mortality daily. During weighing, each animal was examined for the presence of abnormalities. The nesting, littering, :and lactation behavior of the dams was evaluated, along with the littering behaviour of the dams.
Body weights: determined weekly. For females the following exceptions applied: i) during the mating period the parental females were weighed on the day of positive evidence of sperm (day 0 p .c .) and on days 7, 14 and 20 p.c; ii) females showing no positive evidence of sperm in vaginal smears were weighed weekly during the mating interval . These body weight data were solely used for the calculations of the dose; iii) females with litter were weighed on the day of parturition (day 0 p .p .) and on days 4 and 7 p.p; iv) females without litter were weighed weekly . These body weight data were solely used for the calculations of the dose volume
Food consumption: determined weekly

Oestrous cyclicity (parental animals):

not measured

Sperm parameters (parental animals):

not measured

Litter observations:

Clinical signs of toxicity: as soon as possible post parturition pups were observed for external abnormalities, thereafter daily.
Sex ratio: soon as possible post parturition and also on day 4 post parturition
Body weight: wieghed on the day after bith (day 1 p.p) and on day 4 p.p

Postmortem examinations (parental animals):

Histopathology:
need Appendix III of the report to confirm this

Organ weights:
need Appendix III of the report to confirm this

Postmortem examinations (offspring):

Necropsy:
All surviving pups (after sacrifice on day 4 p.p.), all stillborn pups and those pups that died before schedule, were examined externally, eviscerated and their organs were assessed macroscopically. All pups without any notable findings or abnormalities were discarded after their macroscopic evaluation.

Histopathology:
need Appendix III of the report to confirm this

Statistics:

Dunnett test: food consumption (parental animals), body weights and body weight change (parental animals and pups), number of mating days, duration of gestation, number of implantations, proportion of post-implantation loss and number of pups delivered/litter . For the body weight and the body weight change of the pups the mean weight of each litter was used for the statistical analysis (statistical unit = litter) .

Fisher's exact test: male and female mating index, male and female fertility index, gestation index, females with liveborn, stillborn and with all stillborn pups, pups liveborn, pups stillborn, pups died, pups cannibalized, pups sacrificed moribund, viability index, number of litters with affected pups at necropsy.

Wilcoxon-test: used for a comparison of each dose group with the control for the hypothesis of equal medians. This test was performed one-sided and was used for the proportion of affected pups/litter with necropsy observations.

Reproductive indices:

Males: The mating partners, the number of mating days until vaginal sperm could be detected in the female animals, and the pregnancy status of the female partner were noted for F0 breeding pairs. For the males, mating and fertility indices were calculated according to the following formulas:
- male mating index (%) = (no. of males with confirmed mating / no. of males placed with females) x 100
- male fertility index (%) = (no. of males providing their fertility / no. of males placed with females) x 100

Females: The mating partners, the number of mating days until vaginal sperm could be detected, and pregnancy status were recorded
For the females, mating ; fertility and gestation indices were calculated according to the following formulas:
- female mating index (%) = (no. of females mated / no. of females placed with males) x 100
- female fertility index (%) = (no. of females pregnant / no. of females mated) x 100
- gestation index (%) = (no. of females with live pups on the day of birth / no .of females pregnant) x 100

After sacrifice of the female animals, the implantation sites were counted and the post-implantation loss was calculated for each individual pregnant animal according to the following formula:
- post-implantation loss (%) = ((no. of implantations - no. of pups delivered) / no. of implantations)) x 100

Offspring viability indices:

Pup viability:
Viability index (%) = (no. of live pups on day 4 after birth / no. of liveborn pups on the day of birth) x 100

Sex ratio = (no. of live male or female pups on day 0 and day 4 / no. of live male and female pups on day 0 and day 4) x 100

Results and discussion

Results: P0 (first parental generation)

General toxicity (P0)

Clinical signs:

no effects observed

Description (incidence and severity):

There were no differences between treated and control groups in clinical condition

Dermal irritation (if dermal study):

not examined

Mortality:

no mortality observed

Description (incidence):

There were no differences between treated and control groups in mortality

Body weight and weight changes:

effects observed, treatment-related

Description (incidence and severity):

Body weights and body weight gain (refer to Table CA 7.8.1/01)
Males:
1000 mg/kg bw/d: statistically significant lower mean body weights were seen during the last week (week 4) of the administration period. The mean body weight of these animals was about 5% lower than that of the corresponding control group.

Body weight gains of the high dose males were statistically significantly diminished during weeks 2-3 and also, for the weight gain for the total study period (weeks 0- 4). In total, body weight gain was ~49% lower than the concurrent control group.

The lower mean body weights and the depression in body weight gain were deemed to be related to test article administration and were consistent with the reductions in food consumption which occurred in this dose group.

400 and 100 mg/kg bw/d: body weights and body weight gains were unaffected by treatment, with the values similar to the control group

Females:
Body weights/body weight gains from the 100, 400, 1000 mg/kg groups were similar to the control group during premating, gestation and lactation periods.

Food consumption and compound intake (if feeding study):

effects observed, treatment-related

Description (incidence and severity):

Food consumption (refer to Table CA 7.8.1/02)
Males:
1000 mg/kg bw/d: food consumption was statistically significantly reduced during study weeks 0- 1 and 3 – 4.
If calculated for the total study period weeks 0- 4), food consumption was 8% lower than the corresponding control value. This was considered to be substance-related, because the slight reductions in food consumption were consistent with lower mean body weights and impaired body weight gains.

400 and 100 mg/kg bw/d: food consumption was unaffected by treatment, with the values similar to the control group

Females:
Food consumption from the 100, 400, 1000 mg/kg groups were similar to the control group during premating, gestation and lactation periods.

Food efficiency:

not examined

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

not examined

Ophthalmological findings:

not examined

Haematological findings:

not examined

Clinical biochemistry findings:

not examined

Urinalysis findings:

not examined

Behaviour (functional findings):

not examined

Immunological findings:

not examined

Histopathological findings: non-neoplastic:

no effects observed

Histopathological findings: neoplastic:

not examined

Other effects:

not examined

Reproductive function / performance (P0)

Reproductive function: oestrous cycle:

not examined

Reproductive function: sperm measures:

not examined

Reproductive performance:

no effects observed

Description (incidence and severity):

Reproductive performance (refer to Table CA 7.8.1/03)
Males:
For all F0 males of in dose groups 0, 100 and 1000 mg/kg bw/d which were placed with females to generate F0 pups, mating was confirmed; thus, the male mating index for these groups was 100% . Due to the fact that no sperm was detected in the vaginal smear of the female partner of male No . 27 (400 mg/kg bw/d), the male mating index was 90% for the mid dose group. This single incide was deemed unrelated to treatment.

The mean duration until sperm was detected (day 0 p .c .), varied between 2 .6 and 3 .0 days and did not show a clear dose-response relationship . These
values are fully within the expected range of biological variation for the rat strain used.

Females:
The female mating index calculated after the mating period was 100% for dose groups 0, 100 and 1000 mg/kg bw/d. As female No. 127 (400 mg/kg bw/d) showed no sperm in vaginal smear and did not give birth to a litter, the female mating index for dose group 400 mg/kg bw/d was 90%.

Fertility index: all females from test groups becomae pregnant. Therefore a 100% fertility index was calculated for all groups.

Gestation index: gestation was similar in all groups, the gestation ándeA reached 100% in all groups

The mean number of implantation sites, the postimplantation loss values and the mean number of delivered pups/dam were similar for the test article treated groups and the concurrent control group . The observable differences have no biological relevance and/or are not dose-related . The mean number of delivered pups/dam was lowest in the control group .

Effect levels (P0)

1

Key result

Dose descriptor:

NOAEL

Effect level:

ca. 400 mg/kg bw/day (nominal)

Based on:

test mat.

Sex:

male

Basis for effect level:

body weight and weight gain

food consumption and compound intake

2

Key result

Dose descriptor:

NOAEL

Effect level:

ca. 1 000 mg/kg bw/day (nominal)

Based on:

test mat.

Sex:

female

Basis for effect level:

other: no effects obs. up to the maximum recommended dose tested

Remarks on result:

not determinable due to absence of adverse toxic effects

Results: F1 generation

General toxicity (F1)

Clinical signs:

effects observed, non-treatment-related

Description (incidence and severity):

Filiformed tail and acaudia were the only clinical observations which occurred and both were recorded for one low dose pup (#17 from dam #113) . This pup had a filiformed tail at birth and the first day after birth . Thereafter, it lost its malformed tail completely and therefore "acaudia" was observed. These findings are considered to be spontaneous in nature, because no relation to dosing is given

Dermal irritation (if dermal study):

not examined

Mortality / viability:

no mortality observed

Description (incidence and severity):

No test article related effects on pup viability/mortality were recorded during the lactation period. The viability index, as an indicator for the viability of the pups during the first 4 days after birth, was similar in all groups as was the mean number of live pups/litter on days 0 and 4 p.p. The observable differences have no biological relevance and/or are not dose-related.

Body weight and weight changes:

no effects observed

Description (incidence and severity):

refer to Table CA 7.8.1/04
Mean body weights/body weight gains were not influenced by the test article administration. On day 4 p.p., the day of scheduled pup sacrifice, the mean pup body weights for males+females were 9 .6/9.8/9.4/9.8g in the 0/100/400/1000 mg/kg bw/d groups, respectively.

Pup body weight gains between days 1-4 p.p. were also very similar between the groups. The observable differences have no biological relevance and/or are not dose-related.

Food consumption and compound intake (if feeding study):

not examined

Description (incidence and severity):

pups killed day 4 p.p.

Food efficiency:

not examined

Description (incidence and severity):

pups killed day 4 p.p.

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

not examined

Description (incidence and severity):

pups killed day 4 p.p.

Ophthalmological findings:

not examined

Description (incidence and severity):

pups killed day 4 p.p.

Haematological findings:

not examined

Clinical biochemistry findings:

not examined

Urinalysis findings:

not examined

Description (incidence and severity):

pups killed day 4 p.p.

Sexual maturation:

not examined

Description (incidence and severity):

pups killed day 4 p.p.

Organ weight findings including organ / body weight ratios:

not examined

Description (incidence and severity):

pups killed day 4 p.p.

Gross pathological findings:

effects observed, non-treatment-related

Description (incidence and severity):

Only spontaneous findings were seen at necropsy (e.g. dilated renal pelvis and acaudia) in very few of the pups examined. These findings occurred exclusively in the low and mid dose groups and therefore were not dose related (refer to Table CA 7.8.1/01/6)

Histopathological findings:

effects observed, non-treatment-related

Description (incidence and severity):

The clinical finding "acaudia" in the low dose pup #17 (from dam #113) was confirmed by the additional examination of the skeleton of this pup according to modified DAWSON's method. The skeletal examination revealed the absence of all caudal vertebrae.

Other effects:

not examined

Description (incidence and severity):

pups killed day 4 p.p.

Developmental neurotoxicity (F1)

Behaviour (functional findings):

not examined

Description (incidence and severity):

pups killed day 4 p.p.

Developmental immunotoxicity (F1)

Developmental immunotoxicity:

not examined

Description (incidence and severity):

pups killed day 4 p.p.

Details on results (F1)

pups killed day 4 p.p.

Effect levels (F1)

Key result

Dose descriptor:

NOAEL

Generation:

F1

Effect level:

ca. 1 000 mg/kg bw/day (nominal)

Based on:

test mat.

Sex:

male/female

Remarks on result:

not determinable due to absence of adverse toxic effects

Overall reproductive toxicity

Reproductive effects observed:

no

Any other information on results incl. tables

Table CA 7.8.1/01-1:
Bodyweight during pre-mating, gestation and lactation (±sd)

Parameter	Dose levels (mg/kg bw/d) [Males]				Dose levels (mg/kg bw/d) [Females]
	0	100	400	1000	0	100	400	1000
Pre-mating
Week 0	392 ±10.16	394 ±6.10	394 ±10.47	396 ±11.61	234 ±4.05	234 ±6.42	236 ±4.94	235 ±7.77
Week 1	401.5 ±14.94	407 ±11.77	409 ±13.13	400 ±14.97	235 ±10.37	235 ±7.26	239 ±7.48	236 ±7.46
Week 2	412 ±15.91	421 ±14.64	420 ±12.77	406 ±17.45	239 ±11.85	241 ±6.02	242 ±9.30	244 ±9.78
Week 3	423 ±11.16	431 ±16.41	432 ±13.3	400 ±19.29	-	-	-	-
Week 4	441 ±12.79	450 ±14.44	450 ±15.16	420 ±22.31*	-	-	-	-
Bwt change Week 0-4	49 ±9.17	56 ±10.63	56 ±14.22	25 ±14.30**	-	-	-	-
Bwt change Week 0-2	-	-	-	-	5.5 ±9.56	7.0 ±9.43	5.8 ±6.59	9.5 ±5.47
Gestation
Day 0	-	-	-	-	251 ±10.60	249 ±5.83	252 ±9.74	252 ±11.90
Day 7	-	-	-	-	276 ±12.19	281 ±7.60	281 ±10.38	281 ±10.58
Day 14	-	-	-	-	311 ±14.04	317 ±10.91	315 ±12.07	313 ±12.53
Day 20	-	-	-	-	380 ±16.83	392 ±20.23	397 ±18.52	390 ±17.10
Bwt change Days 0-20	-	-	-	-	129 ±18.87	144 ±18.87	145 ±12.58	139 ±15.29
Lactation
Day 0	-	-	-	-	300 ±18.62	309 ±9.63	301 ±9.84	299 ±12.36
Day 4	-	-	-	-	313 ±14.07	320 ±10.75	319 ±15.73	306 ±15.93
Day 7	-	-	-	-	306 ±15.38	311 ±13.15	307 ±9.96	303 ±11.32
Bwt change Days 0-7	-	-	-	-	5.8 ±9.49	1.9 ±12.19	6.5 ±9.34	4.4 ±10.58

* p<0.05; ** p <0.01

 

Table CA 7.8.1/01-2:
Food consumption during pre-mating, gestation and lactation (±sd)

Parameter	Dose levels (mg/kg bw/d) [Males]				Dose levels (mg/kg bw/d) [Females]
	0	100	400	1000	0	100	400	1000
Pre-mating
Week 0 to 1	24.6 ±1.64	25.8 ±1.68	25.9 ±1.78	22.6 ±1.80*	17.7 ±1.69	17.9 ±0.89	18.1 ±1.15	17.8 ±1.50
Week 1 to 2	24.2 ±1.35	25.7 ±1.73	25.5 ±1.18	22.9 ±1.89	18.4 ±1.25	18.1 ±1.51	18.0 ±1.68	18.6 ±1.46
Week 3 to 4	25.6 ±1.66	26.5 ±1.38	26.8 ±1.46	23.2 ±1.35**	-	-	-	-
Week 0-4	24.8 ±0.70	26.0 ±0.48	26.0 ±0.67	22.9 ±0.30	-	-	-	-
Week 0-2	-	-	-	-	18.0 ±0.47	18.0 ±0.16	18.0 ±0.09	18.2 ±0.56
Gestation
Day 0 to 7	-	-	-	-	23.2 ±1.23	24.1 ±1.93	23.3 ±1.55	22.8 ±1.12
Day 7 to 14	-	-	-	-	25.8 ±1.46	26.8 ±1.74	25.4 ±1.64	25.4 ±1.70
Day 14 to 20	-	-	-	-	28.3 ±1.46	29.7 ±1.65	28.1 ±1.51	28.2 ±2.17
Day 0 to 20	-	-	-	-	25.8 ±22.51	26.9 ±2.76	25.6 ±2.41	25.5 ±2.70
Lactation
Day 0 to 4	-	-	-	-	37.3 ±3.06	37.1 ±5.75	39.4 ±6.21	37.9 ±4.92
Day 4 to 7	-	-	-	-	29.9 ±2.31	29.6 ±2.87	29.6 ±1.62	29.4 ±2.90
Day 0 to 7	-	-	-	-	33.6 ±5.28	33.4 ±5.32	34.5 ±6.96	33.6 ±5.99

* p<0.05; ** p <0.01

 

Table CA 7.8.1/01-3:
Summary of reproductive performance

Parameter	Dose levels (mg/kg bw/d)
	0	100	400	1000
Males
Males on study	10	10	10	10
Males with confirmed mating (%)	10 (100%)	10 (100%)	9 (90%)	10 (100%)
Males without confirmed mating (%)	0 (0%)	0 (0%)	1 (10%)	0 (0%)
Males proving their fertility (fertility index%)
Females
Females on study	10	10	9	10
Females mated (mating index%)	10 (100%)	10 (100%)	9 (90%)	10 (100%)
Mating days until day 0 p.c.	2.8 ±1.40	2.6 ±1.26	2.78 ±0.97	3.0 ±3.65
- days 1 to 4	10 (100%)	10 (100%)	9 (90%)	9 (90%)
- days 5 to 8	0 (0%)	0 (0%)	0 (0%)	0 (0%)
- days 9 to 14	0 (0%)	0 (0%)	0 (0%)	1 (10%)
Pregnant at delivery (fertility index)	10 (100%)	10 (100%)	9 (100%)	10 (100%)

 

Table CA 7.8.1/01-4:
Pup bodyweights and body weight changes(g) (±sd)

Parameter	Dose levels (mg/kg bw/d) [Males]				Dose levels (mg/kg bw/d) [Females]
	0	100	400	1000	0	100	400	1000
Day 1	6.8 ±0.43	6.8 ±0.45	6.5 ±0.53	6.7 ±0.43	6.4 ±0.38	6.4 ±0.52	6.4 ±0.53	6.5 ±0.48
Day 4	9.9 ±0.73	10.0 ±0.96	9.5 ±0.93	10.0 ±0.82	9.4 ±0.60	9.8 ±0.98	9.4 ±0.92	9.8 ±0.91
Days 1 to 4	3.2 ±0.37	3.2 ±0.56	3.0 ±0.49	3.2 ±050	3.1 ±0.34	3.1 ±0.66	3.1 ±0.48	3.2 ±0.71

 

Table CA 7.8.1/01-5:
Summary of litter data

Parameter	Dose levels (mg/kg bw/d)
	0	100	400	1000
Implantation sites (total / mean ±SD)	148 /14.8 ±2.10	161 / 16.1 ±1.97	150 / 16.7 ±2.07	164 / 16.4 ±1.90
Post-implantation loss (total / mean ±SD)	17 / 17.1 ±1.49	29 / 2.9 ±2.23	11 / 11.2 ±1.56	20 / 2.0 ±1.76
Duration of gestation (days)	22.0 ±0.00	2.19 ±0.32	22.1 ±0.33	22.1 ±0.32
Females with liveborn (gestation index %)	10 (100%)	10 (100%)	9 (100%)	10 (100%)
- with stillborn pups	0 (0%)	3 (30%)	1 (11%)	0 (0%)
- will all stillborn	0 (0%)	0 (0%)	0 (0%)	0 (0%)
Litters with liveborn pups (%)	10 (100%)	10 (100%)	9 (100%)	10 (100%)
Litters with stillborn pups (%)	0 (0%)	3 (30%)	1 (11%)	0 (0%)
Pups delivered (total / mean ±SD)	131 / 13.1 ±2.13	132 / 13.2 ±3.08	139 / 15.4 ±2.13	144 / 14.4 ±2.22
Pups liveborn	131 (100%)	129 (98%)	132 (97%)	144 (100%)
Pups stillborn	0 (0%)	3 (2.3%)	4 (2.9%)	0 (0%)
Pups died	2 (1.5%)	1 (0.8%)	7 (5.0%)	5 (3.5%)
Pups cannibalised	2 (1.5%)	1 (0.8%)	1 (0.7%)	1 (0.7%)
Pups dead day 0	0 (0%)	0 (0%)	1 (0.7%)	1 (0.7%)
Pups dead days 1 to 4	4 (3.1%)	2 (1.6%)	7 (5.2%)	5 (3.5%)
Pups surviving days 0 to 4 (viability index %)	127 (7%)	127 (98%)	127 (94%)	138 (96%)
Live pups/litter day 0 (total / mean ±SD)	131 / 13.1 ±2.13	129 / 12.9 ±3.03	135 / 15.0 ±1.94	144 / 14.4 ±2.22
Live pups/litter day 4 (total / mean ±SD)	127 / 1.27 ±1.77	127 / 12.7 ±2.98	127 / 14.1 ±2.32	138 / 13.8 ±2.57
Sex ratio: day 0 %live males, % live females	M: 44.3%, F: 55.7%	M: 55.8%, F: 44.2%	M: 54.8%, F: 45.2%	M: 47.2%, F: 52.8%
Sex ratio: day 4 %live males, % live females	M: 44.9%, F: 55.1%	M: 55.9%, F: 44.1%	M: 55.9%, F: 44.1%	M: 47.8%, F: 52.2%

  

Table CA 7.8.1/01-6:
Pup necropsy observations

Parameter	Dose levels (mg/kg bw/d)
	0	100	400	1000
Litter evaluated	10	10	9	10
Pups evaluated	129	131	138	143
- Live	129	128	134	143
Dilated renal pelvis - Pup incidence (%) - Litter incidence (%) - Affected pups/litter (mean%)	0 (0%) 0 (0%) 0 ±0.0	5 (3.8%) 2 (20%) 3.1 ±7.92	1 (0.7%) 1 (11%) 0.7 ±2.08	0 (0%) 0 (0%) 0 ±0.0
Acaudia - Pup incidence (%) - Litter incidence (%) - Affected pups/litter (mean%)	0 (0%) 0 (0%) 0 ±0.0	1 (0.8%) 1 (10%) 0.6 ±1.86	0 (0%) 0 (0%) 0 ±0.0	0 (0%) 0 (0%) 0 ±0.0
Total pup necropsy - Pup incidence (%) - Litter incidence (%) - Affected pups/litter (mean%)	0 (0%) 0 (0%) 0 ±0.0	6 (4.6%) 3 (30%) 3.7 ±7.88	1 (0.7%) 1 (11%) 0.7 ±2.08	0 (0%) 0 (0%) 0 ±0.0

 

Applicant's summary and conclusion

Conclusions:

Based on the results of this study the NOAELs for parental toxicity, reproductive outcome and offspring toxicity of 1,6-hexanediol when administered orally via gavage during pre-mating, gestation and lactation are as follows:

NOAEL for parental toxicity: Males: 400 mg/kg bw/d based on reductions in body weight / body weight gain and food consumption. Females: 1000 mg/kg bw/day, the highest dose tested, based on no adverse effects
NOAEL for reproductive outcome: 1000 mg/kg bw/day, the highest dose tested, based on no adverse effects.
NOAEL for offspring toxicity: 1000 mg/kg bw/day, the highest dose tested, based on no adverse effects

Executive summary:

A screening for reproductive / developmental toxicity study was conducted with 1,6-hexanediol in the Wistar rat. Animals (10/sex/group) were dosed orally via gavage at either 0, 100, 400 or 1000 mg/kg bw/d formulated in distilled water (dose volume 10 mL/kg bw). After at least 14 d of treatment, males and females from the same dose group were mated at a ratio of 1:1. After this mating period, the male animals were sacrificed. The females were allowed to litter and rear their pups until day 4 after parturition (p.p). Thereafter, the pups and the F0 generation female parental animals were sacrificed.

1,6-hexanediol had no adverse effects on fertility, on the parturition process or on peri- and postnatal survival of the offspring (up to day 4 p.p).

Clinical signs of toxicity and mortality were unaffected by treatment in F0 parental animals. Reductions in body weight (week 4) and food consumption (weeks 0 – 1 and 3 – 4) were seen in high dose F0 males. Body weight and food consumption values for F0 females were unaffected by treatment.

There were no treatment-related effects on reproductive performance (including mating, fertility, gestation index). The mean number of implantation sites, the post-implantation loss values and the mean number of delivered pups/dam were similar for the test article treated groups and the concurrent control group. The observable differences have no biological relevance and/or are not dose-related. The mean number of delivered pups/dam was lowest in the control group. Only spontaneous findings were seen at necropsy (e.g. dilated renal pelvis and acaudia) in very few of the pups examined. These findings occurred exclusively in the low and mid dose groups and therefore were not dose related.

No test article related effects on pup viability/mortality were recorded during the lactation period. The viability index, as an indicator for the viability of the pups during the first 4 days after birth, was similar in all groups as was the mean number of live pups/litter on days 0 and 4 p .p. The observable differences have no biological relevance and/or are not dose-related. Mean body weights/body weight gains were not influenced by the test article administration.

Based on the results of this study the NOAELs for parental toxicity, reproductive outcome and offspring toxicity of 1,6-hexanediol when administered orally via gavage during pre-mating, gestation and lactation are as follows:

NOAEL for parental toxicity: Males: 400 mg/kg bw/d based on reductions in body weight / body weight gain and food consumption. Females: 1000 mg/kg bw/day, the highest dose tested, based on no adverse effects

NOAEL for reproductive outcome:1000 mg/kg bw/day, the highest dose tested, based on no adverse effects.

NOAEL for offspring toxicity: 1000 mg/kg bw/day, the highest dose tested, based on no adverse effects.