Hexane-1,6-diol

Toxicity to reproduction

Administrative data

Endpoint:

screening for reproductive / developmental toxicity

Remarks:

based on test type (migrated information)

Type of information:

experimental study

Adequacy of study:

key study

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: Guideline study (OECD)

Cross-reference

Reason / purpose for cross-reference:

reference to same 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:

draft

GLP compliance:

yes

Remarks:

Department of Toxicology, BASF AG

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

Details on test material:

- Name of test material (as cited in study report): 1,6-Hexandiol
- Test substance No. : 93/23 0
- Date of production : Dec . 17 - 21, 1993
- Physical state: solid - liquid/colorless
- Analytical purity: 97%
- Purity test date: February 9, 1994
- Lot/batch No.: Tank 19
- Storage condition of test material: room temperature; in a closed container due to the hygroscopic properties of the test substance

Test animals

Species:

rat

Strain:

Wistar

Sex:

male/female

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Source: Dr . K . THOMAE GmbH, Biberach an der Riss, Germany
- Age at study initiation: (P) 12 wks
- Weight at study initiation: (P) Males: 394.0 (369.4 - 414.0) g; Females: 234.7 (224.4 - 248.0) g
- Fasting period before study:
- Identification: ear tattoo; pups by skin tattoo
- Housing:individually in type DK III stainless steel wire mesh cages supplied by BECKER & CO., Castrop-Rauxel, Germany (floor area of about 800 cm2). For the overnight mating the females were put into the cages of the males; from day 18 pc until sacrifice, the pregnant animals and their litters were housed in Makrolon type MIII cages (floor area about 800 cma)o The MIII cages were also supplied by BECKER & CO. Pregnant females were provided with nesting material (cellulose wadding) toward the end of pregnancy. The cages with the test animals were arranged on the racks in such a way that uniform experimental conditions (ventilation and light) were ensured. The bedding used throughout the study was Ssniff (type 3/4 ) supplied by SSN IFF S PEZIALDIATEN GmbH, Soest, Germany.
- Diet (e.g. ad libitum): ad libitum, ground Kliba maintenance diet rat/mouse/hamster GLP 343 meal, supplied by KLINGENTALNlOHLE AG, Kaiseraugst, Switzerland
- Water (e.g. ad libitum): Drinking water of tap water quality was supplied from water bottles
- Acclimation period: 7 d


ENVIRONMENTAL CONDITIONS
- Temperature (°C): 20 -24
- Humidity (%): 30 - 70
- Air changes (per hr):
- Photoperiod (hrs dark / hrs light): 12 / 12

Administration / exposure

Route of administration:

oral: gavage

Vehicle:

water

Details on exposure:

PREPARATION OF DOSING SOLUTIONS:
Before start of study, the test substance was melted at 50°C and homogenated by stirring. Thereafter about 60 samples (one sample for one test
substance preparation) were bottled, numbered consecutively and stored at room temperature. Each day, one of the test substance samples was
melted at 50°C in a water bath, thereafter an appropriate amount of the test substance was weighed and subsequently dissolved in doubly distilled water with a magnetic stirrer for about 5 minutes.

VEHICLE
- Amount of vehicle (if gavage): 10 ml

Details on mating procedure:

- M/F ratio per cage: 1/1
- Length of cohabitation: overnight for max. 2 weeks
- Proof of pregnancy: sperm in vaginal smear referred to as day 0 of pregnancy
- Further matings after two unsuccessful attempts: no
- After successful mating each pregnant female was caged (how): in Makrolon type MIII cages (floor area about 800 cma)o TheMIII cages were also
supplied by BECKER & CO. Pregnant females were provided with nesting material (cellulose wadding) toward the end of pregnancy.

Analytical verification of doses or concentrations:

yes

Details on analytical verification of doses or concentrations:

The analytical examinations mentioned below were carried out in the analytical department of BASF AG (Dr. P. Schmidt responsible):
- Analyses of test substance: Investigations to characterize the test substance in respect to purity and homogeneity were carried out before the start of the study (method: gas chromatography). The stability of the test substance over a period of 17 months was proven. Due to the short study duration, a reanalysis after the experimental phase of the study was not considered necessary. Detailed descriptions of the extent of the analytical
investigations and of the analytical methods employed are stored with BASF AG.
- Analyses of the solutions of test substance: analytical verifications of the stability of the
aqueous test substance solutions for a period of at east 4 hours at room temperature were carried out in study 32M0015/924088) before the beginning of this screening study. Due to the fact, that the test substance preparations were true solutions, it was not necessary to verify the homogeneous distribution by analysis. Samples of the aqueous test substance solutions were sent to the analytical laboratory twice during the study period for verification of the concentrations. The test substance solutions were analyzed by gas
chromatography.

Duration of treatment / exposure:

Exposure period: throughout the whole study period (males: about 4 weeks; females: about 6 weeks)
Premating exposure period (males): at least 14 days
Premating exposure period (females): at least 14 days
Duration of test: until day 4 post partum of F1 generation

Frequency of treatment:

daily

Doses / concentrations

Remarks:

Doses / Concentrations:
100, 400 or 1000 mg/kg/d
Basis:
actual ingested

No. of animals per sex per dose:

10

Control animals:

yes, concurrent vehicle

Details on study design:

- Dose selection rationale: The doses were chosen on the basis of the results from a previous 4-week oral toxicity study (Repeated dose oral toxicity study with 1,6-Hexandiol in Wistar rats; administration by gavage over 4 weeks (Project No . 31S0230/93052; BASF AG,Germany, 1995) in which 5 rats/group and sex received 1,6-Hexandio by gavage in doses of 100, 400 and 1,000 mg/kg body weight/day. In this 4-week study no clear substance-induced effects were recorded.

Examinations

Parental animals: Observations and examinations:

CAGE SIDE OBSERVATIONS: Yes
- Time schedule: daily
- Cage side observations were included: mortality, nesting, littering and lactation behavior

DETAILED CLINICAL OBSERVATIONS: Yes
- Time schedule: daily


BODY WEIGHT: Yes
- Time schedule for examinations: weekly; 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 post coitum; Females with litter were weighed on the day of parturition (day 0 p .p .) and on days 4 and 7 post
partum


FOOD CONSUMPTION AND COMPOUND INTAKE (if feeding study):
- Food consumption for each animal determined and mean daily diet consumption calculated as g food/kg body weight/day: Yes
- Compound intake calculated as time-weighted averages from the consumption and body weight gain data: Yes

Litter observations:

STANDARDISATION OF LITTERS
- Performed on day 4 postpartum: no


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 behavioural abnormalities


GROSS EXAMINATION OF DEAD PUPS:
yes, for external and internal abnormalities; possible cause of death was not determined for pups born or found dead.

Postmortem examinations (parental animals):

SACRIFICE
- Male animals: All surviving animals
- Maternal animals: All surviving animals

Postmortem examinations (offspring):

SACRIFICE
- The F1 offspring was sacrificed at 4th day of age.
- These animals were subjected to postmortem examinations (macroscopic and/or microscopic examination) as follows: examined externally ,
eviscerated and their organs were assessed macroscopically .

Statistics:

The data were evaluated statistically using the computer systems of the Department of Toxicology of BASF AG (laboratory data processing, Dr. H.D. Hoffmann responsible):
The DUNNETT Test, two-sided: 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 postimplantation loss and number of pups delivered per litter .
FISHER's Exact Test, one-sided: 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 is at necropsy
The WILCOXON-Test one-sided: proportion of affected pups per litter with necropsy observations.
If the results of these tests were significant labels (* for p <=00.5, ** for p<=0.01) were printed in the Summary Tables.

Reproductive indices:

Males: mating and fertility indices were calculated
Females: mating, fertility and gestation indices and gestation loss were calculated

Offspring viability indices:

viability index was calculated

Results and discussion

Results: P0 (first parental generation)

Details on results (P0)

CLINICAL SIGNS AND MORTALITY (PARENTAL ANIMALS)
- There were no particular, dose-related findings in F0 males (whole study period) or F0 females (premating, gestation, parturition or lactation).
One control male animal (No. 4) showed a cataract on the left eye from study day 2 until the day of scheduled sacrifice. One 400 mg/kg female (No . 124) showed insufficient nesting activity towards the end of the gestation period. This not dose-related finding occurs also rather frequently in untreated pregnant dams and thus is regarded to be spontaneous in nature.


BODY WEIGHT AND FOOD CONSUMPTION (PARENTAL ANIMALS):
- The food consumption of the high dose male animals was statistically significantly reduced during study weeks 0 - 1 and 3 - 4, whereas the food consumption of the high dose females was not influenced by the test substance administration during premating, gestation and lactation.
- If calculated for the total study period of the males (weeks 0 - 4), the food consumption of the high dose group was 8% lower than the corresponding control value. This is considered to be substance-related, because the slight reductions in food consumption are in-line with lower mean body weights and impaired body weight gains of the 1,000 mg/kg males. However, no substance-related effects on organ weights and no gross- and histopathologicalfindings were observed in F0 males.
- All other differences between the substance-treated and the concurrent control groups concerning food consumption are without any biological relevance and/or not dose-related.
-In the high dose F0 males statistical significant lower mean body weights were seen during the last week of the administration period (week 4). 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, if the weight gain for the total study period (weeks 0 - 4) is calculated. In total, body weight gain of the 1,000 mg/kg males was about 49% lower than the concurrent control value. However, no substance-related effects on organ weights and no gross- and histopathologicalfindings were observed in F0 males. As there is no correlation to organ weigths or any histopathological effect these effects ar considerd not to be adverse

- Body weights/body weight gains of the males of the 100 and 400 mg/kg groups were similar to control values. Body weights/body weight gains of all substance-treated females (100, 400 and 1 0 000 mg/kg body weight/day) were not influenced in a dosedependent manner neither during premating nor during the gestation and lactation periods. All differences in body weights and body weight gains observed for these rats are considered to be spontaneous in nature. This includes the statistical significant increases in dams' body weight gain at 100 mg/kg on gestation days 0- 7 and at 400 mg/kg during gestation days 14 - 20.

REPRODUCTIVE PERFORMANCE (PARENTAL ANIMALS)
- For all F0 males of test groups 0, 1 and 3 (0, 100 and 1,000 mg/kg body weight/day) 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, the male mating index was 90 % for test group 2 (400 mg/kg body weight/day). For all except one (No . 27) F0 males fertility could be confirmed in the scheduled mating interval; the fertility index varied between 90% and 100% with no relation to dosing.
- The female mating index calculated after the mating period varied between 90% (test group 2 - 400 mg/kg body weight/day) and 100 % (test group 0,1 and 3 - 0, 100 and 1,000 mg/kg body weight/day). One 400 mg/kg female (No. 127) showed no sperm in vaginal smear and/or did not give birth to a litter. 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. All mated females of test groups 0 - 3 (0, 100, 400, 1,000 mg/kg body weight/day) became pregnant. Therefore, a 100 % fertility index was calculated for all groups. The mean duration of gestation was similar in all groups, the gestation index 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 substancetreated 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)

Dose descriptor:

NOAEL

Effect level:

1 000 mg/kg bw/day

Sex:

male/female

Basis for effect level:

other: overall effects

Results: F1 generation

Details on results (F1)

VIABILITY (OFFSPRING)
No substance-induced 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.

CLINICAL SIGNS (OFFSPRING)
Filiformed tail and acaudia were the only clinical observations which occurred and both were recorded for one low dose pup (No. 17 from dam No. 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.

BODY WEIGHT (OFFSPRING)
Mean body weights/body weight gains were not influenced by the test substance administration. On day 4 p.p., the day of scheduled pup sacrifice, the mean pup body weights for males+females were 9.6 g in the control group and 9.8, 9.4 and 9.8 g in test groups 1 - 3, 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.

GROSS PATHOLOGY (OFFSPRING)
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 test groups 1 and 2 (100 or 400 mg/kg body weight/day) and thus did not show any relation to dosing. The clinical finding "acaudia" of low dose pup No . 17 (from dam No. 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.

Effect levels (F1)

Dose descriptor:

NOAEL

Generation:

F1

Effect level:

1 000 mg/kg bw/day

Sex:

male/female

Basis for effect level:

other: overall effects

Overall reproductive toxicity

Reproductive effects observed:

not specified

Any other information on results incl. tables

The food consumption of F0 males at the 1000 mg/kg/d dose
level was statistically significantly reduced during study
weeks 0 - 1 and 3 - 4. The mean body weights of those F0 males
were statistically significantly reduced at the end of the
study (study week 4). The body weight gains of the high
doseF0 males were statistically significantly lower compared
to the control F0 males between test weeks 2-3 and over the
total study period (test weeks 0-4). No substance-related
effects on organ weights and no gross- and
histopathologicalfindings were observed in F0 males and
females; no substance- related effects were recorded in F0
male and female rats at the 400 and 100 mg/kg/d dose level
and no substance-related adverse effects were observed in
any of the F1 offspring.

Under the conditions of the study, the test substance
produced marginal signs of parental toxicity in males at
1000 mg/kg/d; however, no signs for general toxicity were
present in males at 400 and 100 mg/kg/d and in females at
1000, 400 and 100 mg/kg/d.
There were no signs for impairment of reproductive function
of F0 rats and no signs of developmental toxicity in their
offspring.
Therefore, the NOAEL for parental and F0 toxicity is 1000 mg/kg/d for females and 400 mg/kg bw for males; the NOAEL's
for reproductive function and for developmental toxicity
are 1000 mg/kg/d.