Propane-1,2,3-triyl 2-ethylhexanoate

Endpoint summary

Key value for chemical safety assessment

Effects on fertility

Description of key information

A prenatal developmental toxicity study has been performed with the registered substance. No adverse effects on any of the reproductive parameters investigated was observed.

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

Additional information

Treatment of pregnant female rats from Day 6 to 19 after mating at dose levels up to and including 1000 mg/kg bw/day was well tolerated and there were no unscheduled deaths or test item-related signs of toxicity. Treatment with the registered substance did not adversely affect the reproductive parameters investigated: gravid uterine weight, incl. cervix and ovaries, corpora lutea, implantation sites, resorption sites (classified as early or late), fetuses (live and dead).

Effects on developmental toxicity

Description of key information

Prenatal developmental toxicity (OECD 414, rat): NOAEL (maternal systemic toxicity) = 1000 mg/kg bw/day; NOAEL (development) = 1000 mg/kg bw/day

Link to relevant study records

Reference

Endpoint:

developmental toxicity

Type of information:

experimental study

Adequacy of study:

key study

Study period:

23 Jan - 9 May 2019

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

OECD Guideline 414 (Prenatal Developmental Toxicity Study)

Version / remarks:

adopted in 2018

Deviations:

no

Qualifier:

according to guideline

Guideline:

EPA OPPTS 870.3700 (Prenatal Developmental Toxicity Study)

Deviations:

no

Qualifier:

according to guideline

Guideline:

other: Japanese Ministry of Agriculture, Forestry and Fisheries, Test Data for Registration of Agricultural Chemicals, 12 Nohsan No. 8147, Agricultural Production Bureau

Version / remarks:

24 November 2000

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Remarks:

The Department of Health of the Government of the United Kingdom, Medicines & Healthcare products Regulatory Agency

Limit test:

no

Species:

rat

Strain:

other: Han Wistar

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Source: Envigo RMS UK
- Age at study initiation: 77 - 83 days
- Weight at study initiation: 182 - 215 g
- Housing: 1 male and 1 female per cage during pairing, 1 female per cage after pairing, in polycarbonate cages
- Diet: SDS VRF1 Certified pelleted diet, ad libitum
- Water: Potable water from the public supply, ad libitum
- Acclimation period: 5 days

IN-LIFE DATES: From: 28 January To: 18 - 21 and 24 February 2019

ENVIRONMENTAL CONDITIONS
- Temperature (°C): 20 - 24
- Humidity (%): 40 - 70
- Air changes (per hr): not specified
- Photoperiod (hrs dark / hrs light): 12 / 12

Route of administration:

oral: gavage

Vehicle:

corn oil

Details on exposure:

PREPARATION OF DOSING SOLUTIONS:
Dosing solutions were prepared weekly by dissolving appropriate amounts of the test material in corn oil yielding final concentrations of 20, 60, and 200 mg/mL.

VEHICLE:
- Concentration in vehicle: 20, 60, and 200 mg/mL
- Amount of vehicle (if gavage): 5 mL/kg bw

Analytical verification of doses or concentrations:

yes

Details on analytical verification of doses or concentrations:

The homogeneity and stability of the dose formulations confirmed as part of an analytical verification study (Envigo Study Number: TP97PW). Formulations in the concentration range 1 to 200 mg/mL were found to be homogenous and stable for 15 days when stored refrigerated (2 to 8°C) and for one day when stored at ambient temperature (15 to 25°C).

Details on mating procedure:

- Impregnation procedure: cohoused
- If cohoused:
- M/F ratio per cage: 1:1
- Proof of pregnancy: Ejected copulation plugs and vaginal smears referred to as day 0 of pregnancy

Duration of treatment / exposure:

Day 6 - 19 of gestation (organogenesis and fetal growth phases of pregnancy in the Han Wistar rat)

Frequency of treatment:

daily, 7 days/week

Duration of test:

14 days

Dose / conc.:

100 mg/kg bw/day (actual dose received)

Dose / conc.:

300 mg/kg bw/day (actual dose received)

Dose / conc.:

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

No. of animals per sex per dose:

20 P females

Control animals:

yes, concurrent vehicle

Details on study design:

- Dose selection rationale: Dose levels were based on the results of a preliminary study for effects on embryo-fetal development, in which animals were orally exposed to 250, 500 and 1000 mg/kg bw/day (Envigo Study No. NX04NY, 2019) for 20 days. In that study no premature deaths occurred or signs of toxicity were observed in association with dose administration. Macroscopic examination did not reveal any abnormalities among the females or the fetuses and litter data parameters as well as mean fetal weights were unaffected by maternal treatment. Therefore, 100, 300 and 1000 mg/kg bw/day were selected as the dose levels for the main study.

Maternal examinations:

CAGE SIDE OBSERVATIONS: Yes
- Time schedule: daily

DETAILED CLINICAL OBSERVATIONS: Yes
- Time schedule: Days 0, 5, 12, 18 and 20 after mating

BODY WEIGHT: Yes
- Time schedule for examinations: Days 0, 3 and 6-20 after mating

FOOD CONSUMPTION: Yes
- Time schedule: Days 0-3, 3-6, 6-10, 10-14, 14-18 and 18-20 after mating
- Food consumption for each animal determined and mean daily diet consumption calculated as g food/kg body weight/day: No
- Compound intake calculated as time-weighted averages from the consumption and body weight gain data: No

WATER CONSUMPTION AND COMPOUND INTAKE (if drinking water study): No

THYROID HORMONE ANALYSIS: Yes; T3, T4 and TSH
- Time schedule and number of animals: at scheduled termination, all animals
- Blood sample site: sublingual vein
- Anesthetic: Yes (isoflurane)

POST-MORTEM EXAMINATIONS: Yes
- Sacrifice on gestation day 20
- Organs examined: Thyroid with parathyroids, gravid uterus (with cervix)

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: half per litter: including the head/brain
- Skeletal examinations: Yes: half per litter

Statistics:

Body weight, gravid uterus weight, food consumption, corpora lutea, implantations, pre/post implantation loss, live young, sex ratio - percentage male, placental, litter and fetal weights, ano-genital distance and organ weight data:
A parametric analysis was performed if Bartlett's test for variance homogeneity was not significant at the 1% level. For pre-treatment data, analysis of variance was used to test for any group differences. Where this was significant (p<0.05) inter group comparisons using t-tests, with the error mean square from the one-way analysis of variance, were made. For all other analyses the F1 approximate test was applied.
A non-parametric analysis was performed if Bartlett's test was still significant at the 1% level following both logarithmic and square-root transformations. For pre treatment data, Kruskal-Wallis’ test was used to test for any group differences. Where this was significant (p<0.05) inter group comparisons using Wilcoxon rank sum tests were made. For all other analyses the H1 approximate test was applied.

Clinical signs:

no effects observed

Description (incidence and severity):

The test item was well tolerated. There were no unscheduled deaths, no test item-related changes in general clinical condition and no signs of toxicity observed.

Mortality:

no mortality observed

Description (incidence):

Administration of Propane-1,2,3-Triyl 2-Ethylhexanoate at dose levels up to and including 1000 mg/kg/day was well tolerated. There were no unscheduled deaths at any dose level investigated.

Body weight and weight changes:

no effects observed

Description (incidence and severity):

There was no effect of treatment on mean body weight gain at any dose level.
The mean gravid uterine weight on gestation day (GD) 20 was essentially similar in all groups. When overall mean body weight gain was adjusted for the contribution of the gravid uterus, net mean body weight gain was similar in all groups of females and unaffected by treatment with the test item.

Food consumption and compound intake (if feeding study):

no effects observed

Description (incidence and severity):

The mean food consumption was unaffected by test item administration at all dose levels investigated.

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:

no effects observed

Description (incidence and severity):

The group mean absolute and adjusted thyroid/parathyroid weights were unaffected by treatment at all dose levels investigated.

Gross pathological findings:

no effects observed

Description (incidence and severity):

There were no maternal macroscopic abnormalities detected at scheduled termination.

Neuropathological findings:

not examined

Histopathological findings: non-neoplastic:

no effects observed

Description (incidence and severity):

The microscopic examination of the thyroid glands after treatment revealed no test item-related lesions in the treated animals.

Histopathological findings: neoplastic:

not examined

Other effects:

no effects observed

Description (incidence and severity):

Thyroid hormone analysis: No effects on serum T3, T4 and TSH concentrations were noted.
In more detail, serum T3 and T4 concentrations in adult females showed a moderate degree of variability in all groups, including Controls. There was no evidence of an effect of treatment with Propane-1,2,3-Triyl 2-Ethylhexanoate on T3 or T4 concentrations at any dose level investigated.
Serum TSH concentrations in adult females also showed a moderate degree of variability in all groups, including Controls. There was considered to be no effect of treatment with Propane-1,2,3-Triyl 2-Ethylhexanoate on TSH concentrations at any dose level investigated.
It was noted that TSH concentrations for females given 1000 mg/kg/day were statistically significantly increased when compared to Controls. This difference was attributable to two females which yielded atypically high results when compared to the other females in the test group, and no effect of Propane-1,2,3-Triyl 2-Ethylhexanoate administration was considered to be inferred.

Number of abortions:

no effects observed

Description (incidence and severity):

At scheduled termination on Day 20 after mating, with the exception of one female given 300 mg/kg bw/day, which had a total litter resorption (unilateral pregnancy; only two early resorptions present in utero), all females were pregnant with live young.
Therefore, the following results were based on 20, 20, 19 and 20 females/litters in control group, 100 mg/kg bw/day, 300 mg/kg bw/ day, and 1000 mg/kg bw/day, respectively.

Pre- and post-implantation loss:

no effects observed

Description (incidence and severity):

There was no effect of maternal treatment on the levels of pre or post implantation losses at any dose level investigated.

Total litter losses by resorption:

no effects observed

Description (incidence and severity):

On Day 20 after mating, one female given 300 mg/kg bw/day had a total litter resorption (unilateral pregnancy; only two early resorptions present in utero).

Early or late resorptions:

no effects observed

Description (incidence and severity):

There was no effect of maternal treatment on resorptions (early or late) at any dose level investigated.

Dead fetuses:

no effects observed

Description (incidence and severity):

There was no effect of maternal treatment on live young at any dose level investigated.

Changes in pregnancy duration:

no effects observed

Changes in number of pregnant:

no effects observed

Details on maternal toxic effects:

GRAVID UTERINE WEIGHT
The mean gravid uterine weight on Day 20 of gestation was similar in the treatment and control groups. When overall mean body weight gain was adjusted for the contribution of the gravid uterus, net mean body weight gain was similar in all groups and unaffected by treatment.

Key result

Dose descriptor:

NOAEL

Remarks:

maternal systemic toxicity

Effect level:

>= 1 000 mg/kg bw/day (nominal)

Based on:

test mat.

Basis for effect level:

other: no adverse effects observed

Key result

Abnormalities:

no effects observed

Fetal body weight changes:

no effects observed

Description (incidence and severity):

There was no effect of maternal treatment on mean placental weight, total litter weight or fetal weights at any dose level investigated.

Reduction in number of live offspring:

no effects observed

Description (incidence and severity):

There was no effect of maternal treatment on the live young at any dose level investigated.

Changes in sex ratio:

no effects observed

Description (incidence and severity):

There was no effect of maternal treatment on the sex ratio at any dose level investigated.

Changes in litter size and weights:

no effects observed

Description (incidence and severity):

There was no effect of maternal treatment on total litter weight or fetal weights at any dose level investigated.

Changes in postnatal survival:

not examined

External malformations:

effects observed, non-treatment-related

Description (incidence and severity):

Detailed external, visceral and skeletal fetal examination did not reveal any abnormalities which were considered to be related to Propane-1,2,3-Triyl 2-Ethylhexanoate administration.
A very low incidence of major abnormalities were detected at 300 and 1000 mg/kg bw/day (1/206 fetuses and 3/222 fetuses, respectively). Although for some of these major abnormalities there were so far no cases in the historical control data (HCD) range (studies conducted during April 2018 to April 2019; n=6), these were considered spontaneous malformations and, at such a low incidence/ single occurence, are not thought to be related to treatment with the test item.

Skeletal malformations:

effects observed, non-treatment-related

Description (incidence and severity):

Detailed external, visceral and skeletal fetal examination did not reveal any abnormalities which were considered to be related to Propane-1,2,3-Triyl 2-Ethylhexanoate administration.
At 100 and 1000 mg/kg bw/day there was a slight increase in incidence of incompletely ossified cranial centres compared to concurrent control, with the fetal incidence at 100 mg/kg/day and the litter incidence at 100 and 1000 mg/kg bw/day being slightly above the HCD range. In addition, at 1000 mg/kg bw/day there was a slight increase in incidence of ossified cervical vertebral centra compared to concurrent control, although the fetal and litter incidences were within HCD range. Incomplete ossification is a transient stage in fetal development and therefore not considered adverse.
At 300 mg/kg bw/day, a slight increase in incidence of partially fused jugal/maxilla compared to concurrent control was apparent, with the fetal and litter incidences being slightly above the HCD. Since similar increases were not evident at 1000 mg/kg bw/day and as partial fusion of the jugal to maxilla is a transient marker of fetal maturity, the slight increase in incidence in the intermediate dose group only was considered to be incidental and unrelated to maternal treatment.

Visceral malformations:

no effects observed

Description (incidence and severity):

Detailed external, visceral and skeletal fetal examination did not reveal any abnormalities which were considered to be related to Propane-1,2,3-Triyl 2-Ethylhexanoate administration.

Other effects:

no effects observed

Description (incidence and severity):

ANO-GENITAL DISTANCE
Mean ano-genital distance of the male and female fetuses was comparable between treatment and control groups.

Key result

Dose descriptor:

NOAEL

Remarks:

development

Effect level:

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

Based on:

test mat.

Sex:

male/female

Basis for effect level:

other: no adverse effects observed

Key result

Abnormalities:

no effects observed

Key result

Developmental effects observed:

no

Conclusions:

Propane-1,2,3-triyl 2-ethylhexanoate had no effect on intrauterine development of fetuses when administered to pregnant Wistar rats.

Effect on developmental toxicity: via oral route

Endpoint conclusion:

no adverse effect observed

Dose descriptor:

NOAEL

1 000 mg/kg bw/day

Quality of whole database:

The available information comprises an adequate and reliable prenatal developmental toxicity study (Klimisch score 1) conducted with the registered substance. The selected study is thus sufficient to fulfil the standard information requirements set out in Annex VIII, Item 8.7, in accordance with Annex XI, Item 1.5, of Regulation (EC) No. 1907/2006 (REACH).

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

Propane-1,2,3-triyl 2-ethylhexanoate was investigated for adverse effects on prenatal development in a study conducted according to OECD guideline 414 and under GLP conditions (Envigo, 2019b). The test substance was administered during the organogenesis and fetal growth phases of pregnancy (Days 6 to 19 of gestation) in the Han Wistar Rat. Three groups of 20 females received the test substance at doses of 100, 300 or 1000 mg/kg bw/day by oral gavage. A control group received the vehicle (corn oil) only. Animals were killed on Day 20 after mating for reproductive assessment and fetal examination. Clinical observations (Days 0, 5, 12, 18 and 20 after mating), body weight (Days 0, 3 and 6-20 after mating) and food consumption (Days 0-3, 3-6, 6-10, 10-14, 14-18 and 18-20 after mating) were recorded. Adult females were examined macroscopically at necropsy on Day 20 after mating and the gravid uterus weight and thyroid weight were recorded. Microscopic pathology investigations of the maternal thyroid glands were also performed. Ano-genital distance was measured in the fetuses. All fetuses were examined externally at necropsy and subsequently by detailed internal visceral examination or skeletal examination. Treatment of pregnant female rats with the test item was well tolerated and there were no unscheduled deaths or test item-related signs. Group mean body weight gain, gravid uterine weight, adjusted body weight gain, food consumption and thyroid/parathyroid weights were unaffected at all dose levels investigated, and there were no test item-related maternal macroscopic abnormalities detected at scheduled termination. Histopathological examination of the thyroids did not reveal any test item-related lesions. There was no effect of the test substance on T3/T4 or TSH concentrations at any dose level investigated. There was also no effect of maternal exposure to the test substance on developmental parameters, as assessed by the mean numbers of implantations, resorptions, live young, sex ratio and pre- and post-implantation losses. Placental weight, litter weight and fetal weights and ano-gential distance were similar between treatment groups and control. The very low incidence (i.a. single occurence) of major fetal abnormalities were considered spontaneous and are not thought to be related to treatment with the test item. Minor fetal abnormalities, skeletal variants and macroscopic abnormalities included delayed ossification, which is a transient stage in fetal development and therefore not considered adverse, and slight increase in incidence of partially fused jugal to maxilla in the mid dose group, which did not show a dose-response relationship and is a transient marker of fetal maturity. Therefore, the slight increase in incidence of partially fused jugal to maxilla in the intermediate dose group only was considered to be incidental and unrelated to maternal treatment with the test substance. Based on the results, it was concluded that the high dose level of 1000 mg/kg bw/day (the limit dose) represented the No Observed Adverse Effect Level (NOAEL) for maternal toxicity and for embryo-fetal survival, growth and development.

Justification for classification or non-classification

The available data on reproductive / developmental toxicity do not meet the criteria for classification according to Regulation (EC) No. 1272/2008, and are therefore conclusive but not sufficient for classification.