3-[[5-methyl-2-(1-methylethyl)cyclohexyl]oxy]propane-1,2-diol

Endpoint summary

Key value for chemical safety assessment

Effects on fertility

Effect on fertility: via oral route

Endpoint conclusion:

no study available

Effect on fertility: via inhalation route

Endpoint conclusion:

no study available

Effect on fertility: via dermal route

Endpoint conclusion:

no study available

Effects on developmental toxicity

Description of key information

Under test conditions, administration of 3-L-Menthoxypropane-1,2-diol (Takasago Coolact 10) to female Crl: CD VAF/Plus rats during Day 6-15 of gestation, at dose levels of 100, 500 and 1500 mg/kg bw/day by intragastric intubation revealed a NOAEL of 500 mg/kg bw/day for maternal toxicity and NOAEL of >1500 mg/kg bw/day for developmental toxicity.

Link to relevant study records

Reference

Endpoint:

developmental toxicity

Type of information:

experimental study

Adequacy of study:

key study

Study period:

18 February 1992 to 13 March 1992

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

comparable to guideline study with acceptable restrictions

Qualifier:

equivalent or similar to guideline

Guideline:

OECD Guideline 414 (Prenatal Developmental Toxicity Study)

Deviations:

yes

Remarks:

The test animals were exposed to the test material orally from Day 6-15 of gestation instead of guideline recommendation of dosing from implantation (e.g., day 5 post mating) to the day prior to scheduled caesarean section.

GLP compliance:

yes

Remarks:

According to US FDA GLP Regulations

Limit test:

no

Species:

rat

Strain:

other: Charles River Crl: CD VAF/Plus

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Age at study initiation: 77 days old at the beginning of the study and approximately 12.5 weeks at the time of pairing
- Weight at study initiation: 225 - 296 g (on gestation day 0)
- Fasting period before study: Not reported
- Housing: The females were housed individually (except for first five days of acclimation; two/cages) in suspended, stainless steel, wire-mesh cages from receipt until euthanasia.
- Diet: Basal laboratory diet; ad libitum
- Water: Tap water; ad libitum
- Acclimation period: The rats were acclimated for a period of 11 days.

ENVIRONMENTAL CONDITIONS
- Temperature: 22.2 - 23.3°C
- Relative Humidity: 55 ± 8%
- Air changes: Not reported
- Photoperiod: 12 hrs Fluorescent lighting/12 hrs dark

IN-LIFE DATES: From Feb. 07, 1992 to Mar.13, 1992

Route of administration:

oral: gavage

Vehicle:

corn oil

Details on exposure:

PREPARATION OF DOSING SOLUTIONS: The test material was prepared for dosing as a solution in corn oil.
- Rate of preparation of dose formulation: Weekly
- Dose volume: 10 mL/kg bw

VEHICLE
- Concentration in vehicle: 10, 50 and 150 mg/mL for 100, 500 and 1500 mg/kg bw/day, respectively

Analytical verification of doses or concentrations:

yes

Details on analytical verification of doses or concentrations:

A sponsor supplied procedure was used in Week 1 which was later modified and included an extra step of the addition of methanolic extract to eliminate the presence of corn oil in final dilutions. This method was subsequently used for analysis of Week 2 and 10-day stability samples.
- Analysis of dosing suspensions was conducted weekly.

TEST SUBSTANCE STABILITY, HOMOGENEITY AND CONCENTRATION ANALYSIS:
The dose mixtures held for 10 days at room temperature contained 101 to 125% of test material concentration indicating stability. Mean homogeneity obtained for all the dose samples were below the target concentrations.
The test mixtures prepared on two separate occasions during the study contained 84 to 102% of the desired test material concentrations.

Details on mating procedure:

- Impregnation procedure: Cohoused
- M/F ratio per cage: 1:1
- Length of cohabitation: Until mating
- Verification of same strain and source of both sexes: Yes, the female and male animals were from the same source and strain.
- Proof of pregnancy: Mating was determined by observing copulatory plug; when confirmed, the same day was referred to as Day 0 of pregnancy.

Duration of treatment / exposure:

Gestation days 6 - 15

Frequency of treatment:

Once daily

Duration of test:

20 days

Dose / conc.:

100 mg/kg bw/day (nominal)

Dose / conc.:

500 mg/kg bw/day (nominal)

Dose / conc.:

1 500 mg/kg bw/day (nominal)

No. of animals per sex per dose:

30 inseminated females/dose

Control animals:

yes, concurrent vehicle

Details on study design:

- Dose selection rationale: The dosages were selected by a previous preliminary range finding study conducted separately. Dose levels of 125, 250, 500, 1000 and 3000 mg/kg bw/day of the test material were administered orally as a single daily dose on gestation days 6 through 15 at a volume of 10 mL/kg to mated Charles River Crl: CD female rats. Maternal toxicity was observed at 3000 mg/kg bw/day group. No decisive treatment related indications of developmental toxicity was observed at the tested dose levels. The NOAEL for maternal toxicity was determined to be 1000 mg/kg bw/day.
- Rationale for animal assignment: The mated females were assigned consecutively in a block design to one control and three test animals. The order in which the mated females were assigned corresponded to the day on which copulation was observed and the order in which the animals appeared in the breeding record.
- Rationale for test system: The rat strain used is appropriate for the study because it is susceptible to known developmental toxicants and the lab had historical control data.
- Rationale for route of administration: Oral route was considered to be the most closely equivalent to typical route of human exposure.

Maternal examinations:

MORTALITY: Yes
- Time schedule: Daily

DETAILED CLINICAL OBSERVATIONS: Yes
- Time schedule: Daily
- Observations: Signs of toxicity

BODY WEIGHT: Yes
- Time schedule for examinations: The body weight of each inseminated female rat was recorded on Days 0, 6, 9, 12, 16 and 20 of gestation.

FOOD CONSUMPTION: Recorded on the corresponding body weight days and was calculated for the following intervals: gestation days 0-6, 6-9, 9-12, 12-16, 16-20 and 0-20. Values for non-gravid animals were excluded from numerisation.

WATER CONSUMPTION AND COMPOUND INTAKE: No

POST-MORTEM EXAMINATIONS: Yes
- Sacrifice on gestation Day 20, by carbon dioxide inhalation
- Organs examined: Necropsy was conducted to examine congenital abnormalities and macroscopic pathological changes of the organs. The ovaries and uteri were examined.

Ovaries and uterine content:

The ovaries and uterine content was examined after termination: Yes
Examinations included:
- Location of viable and non-viable foetuses
- Early and late resorptions
- Number of total implantations and corpora lutea

Fetal examinations:

- External examinations: Yes, all per litter
- Soft tissue examinations: Yes, half per litter. About half of all foetuses were fixed in Bouin's fixative for determination of visceral abnormalities (Wilson technique).
- Skeletal examinations: Yes, half per litter. About half of the foetuses from each litter were fixed in alcohol, macerated in potassium hydroxide and was stained with Alizarin Red S and cleared with glycerine for subsequent skeletal determination.
- Head examinations: No

Statistics:

Data were processed where appropriate to give group mean values and standard deviations. Statistical methods like t-test, ANOVA, Bartlett's test, Chi-square test, Fisher's exact test, Kruskal Wallis test and Mann Whitney-U-test with Bonferroni correction were used wherever appropriate.

Indices:

a) Percentage pre-implantation loss = ((Number of corpora lutea - Number of implantations) / Number of corpora lutea) × 100
b) Percentage post-implantation loss = ((Number of implantations - Number of viable foetuses) / Number of implantations) × 100

Clinical signs:

effects observed, treatment-related

Description (incidence and severity):

In the high dose group, 1500mg/kg bw/day, staining was observed in anogenital and/body surface; red or brown material around the nose, mouth and/or eyes; and/or staining around mouth. Post-dose salivation was observed for most animals in mid- and high- dose groups. The clinical signs in the high- dose group were attributed to the treatment.

Mortality:

mortality observed, treatment-related

Description (incidence):

One animal died on gestation Day 6, after dosing, in the group being dosed with 1500 mg/kg bw/day. The necropsy findings of this animal revealed no gross lesions. Another animal died on gestation Day 13 in the same group. Necropsy revealed discoloration of lungs. As the mortalities are observed only in this high dose group, it was attributed to the test material treatment. No mortalities were observed in the remaining groups.

Body weight and weight changes:

effects observed, treatment-related

Description (incidence and severity):

A slight, but probably biologically significant, inhibition of maternal body weight gain during gestation days 6 - 9 and over the whole treatment interval (6 - 16) was observed for high dose group when compared with the control group. This was followed by marked body weight gain for the high dose group dams during gestation days 9-12 compared to the control dams and it was attributed to the treatment with the test material. Mean maternal body weights in all treatment groups and maternal body weight gains in low- and mid-dose group were generally comparable with the control group values throughout the study period.

Food consumption and compound intake (if feeding study):

effects observed, treatment-related

Description (incidence and severity):

Significantly decreased treatment related reductions in food consumption were noted in the high- dose group during the treatment period. However, mean maternal food consumption was comparable in low-dose, mid-dose and control dams.

Food efficiency:

not examined

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

not examined

Ophthalmological findings:

not examined

Haematological findings:

not examined

Clinical biochemistry findings:

not examined

Urinalysis findings:

not examined

Behaviour (functional findings):

not examined

Immunological findings:

not examined

Organ weight findings including organ / body weight ratios:

effects observed, treatment-related

Description (incidence and severity):

Absolute and relative liver weights increased significantly in high-dose group in comparison to the control group. This increase was attributed to test material.

Gross pathological findings:

not specified

Neuropathological findings:

not examined

Histopathological findings: non-neoplastic:

not examined

Histopathological findings: neoplastic:

not examined

Other effects:

not specified

Number of abortions:

not examined

Pre- and post-implantation loss:

no effects observed

Description (incidence and severity):

The percentage pre-implantation losses observed at 0 (control), 100, 500 and 1500 mg/kg bw/day were 11, 10.8, 8.7 and 6.7, respectively. The percentage post-implantation loss observed in control, 100, 500 and 1500 mg/kg bw/day groups were 4.5, 7.5, 4.3 and 7, respectively. It indicated that significantly higher early resorptions and/or post implantation loses were observed in 100 and 1500 mg/kg bw/day dose groups in comparison to the control groups. Since no other indications of the developmental toxicity were observed in any group, and since these differences from control group were small, they were attributed to normal biological variability rather than the test material.

Total litter losses by resorption:

not examined

Early or late resorptions:

not examined

Dead fetuses:

no effects observed

Description (incidence and severity):

The number of viable foetuses per dam was comparable between the control and treatment groups.

Changes in pregnancy duration:

not examined

Changes in number of pregnant:

no effects observed

Description (incidence and severity):

The pregnancy incidence observed at 0 (control), 100, 500 and 1500 mg/kg bw/day was 96.6, 93.3, 100 and 93.3 %, respectively.

Other effects:

not specified

Key result

Dose descriptor:

NOAEL

Remarks:

maternal toxicity

Effect level:

500 mg/kg bw/day (nominal)

Based on:

test mat.

Basis for effect level:

body weight and weight gain

clinical signs

food consumption and compound intake

mortality

organ weights and organ / body weight ratios

Key result

Abnormalities:

no effects observed

Fetal body weight changes:

no effects observed

Description (incidence and severity):

Mean foetal body weights in the treatment groups were comparable with the control group.

External malformations:

no effects observed

Description (incidence and severity):

No treatment related and biologically significant malformations were observed in the test material treated groups in comparison to the control group.

Skeletal malformations:

no effects observed

Description (incidence and severity):

No treatment related and biologically significant malformations were observed in the test material treated groups in comparison to the control group.

Visceral malformations:

no effects observed

Description (incidence and severity):

No treatment related and biologically significant malformations were observed in the test material treated groups in comparison to the control group.

Other effects:

no effects observed

Description (incidence and severity):

No treatment related and biologically significant treatment-related developmental variations were observed in the test material treated groups in comparison to the control group.

Key result

Dose descriptor:

NOAEL

Remarks:

developmental toxicity

Effect level:

> 1 500 mg/kg bw/day (nominal)

Based on:

test mat.

Sex:

male/female

Basis for effect level:

other: No adverse effects observed at the highest (1500 mg/kg bw/day) dose level.

Remarks on result:

not determinable due to absence of adverse toxic effects

Key result

Abnormalities:

no effects observed

Key result

Developmental effects observed:

no

Table 1: Summary of caesarean data (Study # 37645)

Dose Group (mg/kg bw/day)	Total number of pregnancies	Percentage	Mean number of corpora lutea	Pre-implantation loss (%)	Post-implantation loss (%)	Mean early resorptions	Mean late resorptions
Control	29/30	96.66	18.8	11	4.5	0.7	0
100	28/30	93.33	18.2	10.8	7.5	1.2	0
500	30/30	100	17.8	8.7	4.3	0.7	0
1500	28/30	93.33	18.3	6.7	7	1.2	0

Conclusions:

Under test conditions, administration of 3-L-Menthoxypropane-1,2-diol (Takasago Coolact 10) to female Crl: CD VAF/Plus rats during Day 6-15 of gestation, at dose levels of 100, 500 and 1500 mg/kg bw/day by intragastric intubation revealed a NOAEL of 500 mg/kg bw/day for maternal toxicity and NOAEL of >1500 mg/kg bw/day for developmental toxicity.

Executive summary:

The developmental toxicity study of 3-L-Menthoxypropane-1,2-diol (Takasago Coolact 10) was conducted following methods comparable to the OECD Guideline 414 (Prenatal Developmental Toxicity Study).

Sexually mature Female Charles River Crl: CD VAF/Plus rats weighing 225-296 grams were housed individually (except for first five days of acclimation; two/cages) in suspended, stainless steel, wire-mesh cages.

The animals were maintained under standard laboratory conditions (temperature: 22.2 - 23.3°C, humidity: 55 ± 8%, 12 h fluorescent light/12 h dark cycle per day) and fed on basal laboratory diet and given tap water, ad libitum. The female rats were cohoused with male rats (M/F ratio: 1:1, from same strain and supplier) for mating. Mating was determined by observing copulatory plug; and when confirmed, the same day was referred to as Day 0 of pregnancy.

The inseminated rats were divided into following groups: 0 (vehicle), 100 (low-dose), 500 (mid-dose) and 1500 (high-dose) mg/kg bw/day and were administered with test or control substances from Day 6 through Day 15 post conception. These dosages were selected by a previous preliminary range finding study conducted separately. Each group included 30 inseminated females. Prior to administration, the test material was dissolved in corn oil. Corn oil served as the vehicle control.

All animals were observed daily for mortality and clinical observations. The body weight of each inseminated female rat was recorded on Days 0, 6, 9, 12, 16 and 20 of gestation. Food consumption was recorded on the corresponding body weight days and was calculated for gestation days 0-6, 6-9, 9-12, 12-16, 16-20 and 0-20. Values for non-gravid animals were excluded from numerisation.

On gestation Day 20, the dams were euthanised by carbon dioxide inhalation and examined for congenital abnormalities and macroscopic pathological changes. The ovaries and uterine content (location of viable and non-viable foetuses, early and late resorptions and number of total implantations and corpora lutea) were examined after sacrifice.

Numbers of live and dead foetuses were determined. Each foetus was weighed, sexed and examined externally. About half of the foetuses from each litter were fixed in Bouin's fixative for determination of visceral abnormalities. The other half of foetuses from each litter were fixed in alcohol, macerated in potassium hydroxide and was stained with Alizarin Red S and cleared with glycerine for subsequent skeletal determination.

One animal died on gestation Day 6, after dosing, in treatment group 1500 mg/kg bw/day. The necropsy findings of this animal revealed no gross lesions. Another animal died on gestation Day 13 in the same group. Necropsy revealed discoloration of lungs. As the mortalities are observed only in the high dose group, it was attributed to the test material treatment. No mortalities were observed in the remaining groups.

In the 1500 mg/kg bw/day group, staining was observed in anogenital and/body surface; red or brown material around the nose, mouth and/or eyes; and/or staining around mouth. Post-dose salivation was observed for most animals in 500 and 1500 mg/kg bw/day dose groups. The clinical signs in 1500 mg/kg bw/day dose group were attributed to the treatment.

A slight, but probably biologically significant, inhibition of maternal body weight gain during gestation days 6-9 and over the whole treatment interval (6-16) was observed for 1500 mg/kg bw/day group when compared with the control group. This was followed by marked body weight gain for the high dose group dams during gestation days 9-12 compared to the control dams and it was attributed to the treatment with the test material.

Mean maternal body weights in all treatment groups and maternal body weight gains in 100 and 500 mg/kg bw/day dose group were generally comparable with the control group values throughout the study period. Significantly decreased treatment related reductions in food consumptions were noted in the 1500 mg/kg bw/day dose group during the treatment period. However, mean maternal food consumption was comparable in 100, 500 mg/kg bw/day and control dams.

In necropsy, absolute and relative liver weights increased significantly in 1500 mg/kg bw/day group in comparison to the control group. This increase was attributed to test material.

The pregnancy incidence observed at 0 (control), 100, 500 and 1500 mg/kg bw/day was 96.6, 93.3, 100 and 93.3 %, respectively. Significantly higher early resorptions and/or post implantation loses were observed in 100 and 1500 mg/kg bw/day dose groups in comparison to the control groups. Since no other indications of the developmental toxicity were observed in any group, and since these differences from control group were small, they were attributed to normal biological variability rather than the test substance.

The number of viable foetuses per dam was comparable between the control and treatment groups. Mean foetal body weights in the treatment groups were comparable with the control group.

No treatment related and biologically significant malformations and developmental variations were observed in the test substance treated groups in comparison to the control group.

Under test conditions, administration of 3-L-Menthoxypropane-1,2-diol ( Takasago Coolact 10) to female Crl: CD VAF/Plus rats during Day 6-15 of gestation, at dose levels of 100, 500 and 1500 mg/kg bw/day by intragastric intubation revealed a NOAEL of 500 mg/kg bw/day for maternal toxicity and NOAEL of > 1500 mg/kg bw/day for developmental toxicity.

This teratogenicity study is classified as acceptable, and satisfies the guideline requirements of OECD 414 method.

Effect on developmental toxicity: via oral route

Endpoint conclusion:

no adverse effect observed

Dose descriptor:

NOAEL

1 500 mg/kg bw/day

Study duration:

subacute

Species:

rat

Quality of whole database:

A study conducted under GLP conditions using methodology equivalent to that of a standardised guideline is available, along with a range-finding study conducted under GLP conditions. The quality of the database is therefore considered to be good.

Effect on developmental toxicity: via inhalation route

Endpoint conclusion:

no study available

Effect on developmental toxicity: via dermal route

Endpoint conclusion:

no study available

Additional information

Range-finding Study

The objective of this study was to establish dose levels of3-L-Menthoxypropane-1,2-diol ( Takasago Coolact 10) for developmental toxicity study in rats.

Sexually mature female Sprague-Dawley-derived Charles River Crl: CD VAF/Plus Rats weighing 221-278 grams were housed individually (except during acclimation and mating) in suspended, stainless steel, wire-mesh cages.

The animals were maintained under standard laboratory conditions (temperature: 20-24.4 °C, humidity: 45-5%, 12 hours fluorescent light/12 hours dark cycle per day) and fed on basal laboratory diet and given tap water, ad libitum.

The female rats were cohoused with male rats (M/F ratio: 1:1, from same strain and supplier) for mating. Mating was determined by observing copulatory plug; and when confirmed, the same day was referred to as Day 0 of pregnancy. The inseminated rats were divided into following groups: 0 (vehicle), 125, 250, 500, 1000 and 3000 mg/kg bw/day and were administered with test or control substances from Day 6 through Day 15 post conception. These dosages were selected by the sponsor based on previous studies. Each group consisted of 5 inseminated females.

Prior to test substance administration, the substance was dissolved and thoroughly mixed in corn oil. Corn oil served as the vehicle control. All animals were observed daily for mortality and clinical observations. The body weight of each inseminated female rat was recorded on Days 0, 6, 9, 12, 16 and 20 of gestation.

On gestation Day 20, the dams were euthanized by carbon dioxide inhalation and examined for congenital abnormalities and macroscopic pathological changes. The ovaries and uterine content (location of viable and non-viable foetuses, early and late resorptions and number of total implantations and corpora lutea) were examined after euthanasia. The numbers of live and dead foetuses were determined and each foetus was weighed.

Three animals died at 3000 mg/kg bw/day between gestation Days 8 and 11. The necropsy findings revealed no gross lesions. Necropsy revealed enlarged stomach containing fluid in two of the three animals. These deaths were attributed to the test substance treatment. Survival was 100 % in control group and with remaining test substance treatment groups.

At 3000 mg/kg bw/day, decreased activity, abnormal breathing, staining in anogenital and/body surface, post-dose increased salivation and material around the nose, mouth and/or eyes were observed. In addition, one animal showed signs of post-dose ataxia. The clinical signs in this group were attributed to the test substance.

Treatment-related reductions in body weight were observed throughout the study at 3000 mg/kg bw/day when compared to the control group. These reductions began on gestation Day 9 and continued through the end of the study. At the same dose level, treatment-related body weight gain inhibitions in comparison to the control group were observed throughout the study. A slight increase in body weight gain was observed at 3000 mg/kg bw/day during post-dose (Day 16-20 of gestation) period which was considered to be treatment related. In the control and other treatment groups, body weight and body weight changes were comparable.

No treatment related differences from the control group were observed during necropsy. The liver weights were comparable among the groups.

The pregnancy incidence observed at 0 (control), 125, 250, 500, 1000 and 3000 mg/kg bw/day was 100, 40, 100, 80, 100 and 10% respectively.

Pre-implantation loss was markedly increased relative to the control value, at 125, 250, 500 and 1000 mg/kg bw/day levels. At 3000 mg/kg bw/day, pre-implantation loss was reduced when compared with the control values; however, this result occurred due to the death of three of the five animals in the treatment group. This difference from the control group was not considered to be treatment-related since implantation was presumed to be completed prior to the initiation of the dosing.

No differences were noted regarding the mean number of implantations, resorptions and live foetuses in the treatment groups in comparison to the control groups.

Relative gravid uterine weights and foetal weights were comparable among the treatment and control groups.

Under test conditions, administration of 3-L-Menthoxypropane-1,2-diol ( Takasago Coolact 10) to female Crl: CD VAF/Plus rats during Day 6-15 of gestation, at dose levels of 125, 250, 500, 1000 and 3000 mg/kg bw/day by intragastric intubation revealed a NOAEL of 1000 mg/kg bw/day for maternal toxicity and NOAEL of > 3000 mg/kg bw/day for developmental toxicity.

Further, based on the above results, dose levels of 100, 500 and 1500 mg/kg bw/day were proposed for definitive developmental toxicity (teratogenicity) study.

Main Study

The developmental toxicity study of 3-L-Menthoxypropane-1,2-diol ( Takasago Coolact 10) was conducted following methods comparable to the OECD Guideline 414 (Prenatal Developmental Toxicity Study).

Sexually mature Female Charles River Crl: CD VAF/Plus rats weighing 225-296 grams were housed individually (except for first five days of acclimation; two/cages) in suspended, stainless steel, wire-mesh cages.

The animals were maintained under standard laboratory conditions (temperature: 22.2-23.3 °C, humidity: 55 ± 8 %, 12 h fluorescent light/12 h dark cycle per day) and fed on basal laboratory diet and given tap water, ad libitum. The female rats were cohoused with male rats (M/F ratio: 1:1, from same strain and supplier) for mating. Mating was determined by observing copulatory plug; and when confirmed, the same day was referred to as Day 0 of pregnancy.

The inseminated rats were divided into following groups: 0 (vehicle), 100 (low-dose), 500 (mid-dose) and 1500 (high-dose) mg/kg bw/day and were administered with test or control substances from Day 6 through Day 15 post conception. These dosages were selected by a previous preliminary range finding study conducted separately. Each group included 30 inseminated females. Prior to administration, the test substance was dissolved in corn oil. Corn oil served as the vehicle control.

All animals were observed daily for mortality and clinical observations. The body weight of each inseminated female rat was recorded on Days 0, 6, 9, 12, 16 and 20 of gestation. Food consumption was recorded on the corresponding body weight days and was calculated for gestation days 0-6, 6-9, 9-12, 12-16, 16-20 and 0-20. Values for non-gravid animals were excluded from numerization.

On gestation Day 20, the dams were euthanized by carbon dioxide inhalation and examined for congenital abnormalities and macroscopic pathological changes. The ovaries and uterine content (location of viable and non-viable foetuses, early and late resorptions and number of total implantations and corpora lutea) were examined after sacrifice.

Numbers of live and dead foetuses were determined. Each foetus was weighed, sexed and examined externally. About half of the foetuses from each litter were fixed in Bouin's fixative for determination of visceral abnormalities. The other half of foetuses from each litter were fixed in alcohol, macerated in potassium hydroxide and was stained with Alizarin Red S and cleared with glycerine for subsequent skeletal determination.

One animal died on gestation Day 6, after dosing, in treatment group 1500 mg/kg bw/day. The necropsy findings of this animal revealed no gross lesions. Another animal died on gestation Day 13 in the same group. Necropsy revealed discoloration of lungs. As the mortalities are observed only in the high dose group, it was attributed to the test substance treatment. No mortalities were observed in the remaining groups.

In the 1500 mg/kg bw/day group, staining was observed in anogenital and/body surface; red or brown material around the nose, mouth and/or eyes; and/or staining around mouth. Post-dose salivation was observed for most animals in 500 and 1500 mg/kg bw/day dose groups. The clinical signs in 1500 mg/kg bw/day dose group were attributed to the treatment.

A slight, but probably biologically significant, inhibition of maternal body weight gain during gestation days 6-9 and over the whole treatment interval (6-16) was observed for 1500 mg/kg bw/day group when compared with the control group. This was followed by marked body weight gain for the high dose group dams during gestation days 9-12 compared to the control dams and it was attributed to the treatment with the test substance.

Mean maternal body weights in all treatment groups and maternal body weight gains in 100 and 500 mg/kg bw/day dose group were generally comparable with the control group values throughout the study period. Significantly decreased treatment related reductions in food consumptions were noted in the 1500 mg/kg bw/day dose group during the treatment period. However, mean maternal food consumption was comparable in 100, 500 mg/kg bw/day and control dams.

In necropsy, absolute and relative liver weights increased significantly in 1500 mg/kg bw/day group in comparison to the control group. This increase was attributed to test substance.

The pregnancy incidence observed at 0 (control), 100, 500 and 1500 mg/kg bw/day was 96.6, 93.3, 100 and 93.3 %, respectively. Significantly higher early resorptions and/or post implantation loses were observed in 100 and 1500 mg/kg bw/day dose groups in comparison to the control groups. Since no other indications of the developmental toxicity were observed in any group, and since these differences from control group were small, they were attributed to normal biological variability rather than the test substance.

The number of viable foetuses per dam was comparable between the control and treatment groups. Mean foetal body weights in the treatment groups were comparable with the control group.

No treatment related and biologically significant malformations and developmental variations were observed in the test substance treated groups in comparison to the control group.

Under test conditions, administration of 3-L-Menthoxypropane-1,2-diol ( Takasago Coolact 10) to female Crl: CD VAF/Plus rats during Day 6-15 of gestation, at dose levels of 100, 500 and 1500 mg/kg bw/day by intragastric intubation revealed a NOAEL of 500 mg/kg bw/day for maternal toxicity and NOAEL of > 1500 mg/kg bw/day for developmental toxicity.

This teratogenicity study is classified as acceptable, and satisfies the guideline requirements of OECD 414 method.

Justification for classification or non-classification

In accordance with the criteria for classification as defined in Annex I, Regulation (EC) No 1272/2008, the substance does not require classification with respect to developmental toxicity.