Propylidynetrimethanol, propoxylated

Endpoint summary

Key value for chemical safety assessment

Effects on fertility

Description of key information

Reproductive/developmental toxicity screening test (OECD 421, oral, rat): NOAEL (reproduction/development) >= 1000 mg/kg bw/day (read across from analogue substance propylidynetrimethanol, ethoxylated (CAS No. 50586-59-9, EC No. 500-110-3))

 

An extended one-generation reproductive toxicity study (EOGRTS) according to OECD guideline 443 in the rat by the oral route of exposure with the analogue substance ethane-1,2-diol, propoxylated has been proposed. The decision on the testing proposal is pending. Based on the results of the EOGRTS, the hazard assessment with respect to reproductive toxicity will be updated.

Link to relevant study records

Reference

Reference 1

Endpoint:

screening for reproductive / developmental toxicity

Type of information:

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

Adequacy of study:

key study

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: GLP Guideline study

Qualifier:

according to guideline

Guideline:

OECD Guideline 421 (Reproduction / Developmental Toxicity Screening Test)

Deviations:

no

Qualifier:

according to guideline

Guideline:

other: EPA OPPTS 870.3550 (Reproduction/Developmental Toxicity Screen)

GLP compliance:

yes (incl. QA statement)

Species:

rat

Strain:

Wistar

Sex:

male/female

Route of administration:

oral: gavage

Vehicle:

water

Details on exposure:

PREPARATION OF DOSING SOLUTIONS
The test substance was applied as a solution. To prepare the solution, the appropriate amount of test substance was weighed out depending on the desired concentration. Then the vehicle (drinking water) was filled up to the desired volume, subsequently mixed using a magnetic stirrer. The test-substance preparations were prepared daily.
The daily volume administered was 10 ml/kg of body weight.

Details on mating procedure:

MATING PROCEDURES:
Each of the male and female animals was mated overnight in a 1 : 1 ratio for a maximum of 2 weeks. Throughout the mating period, each female animal was paired with a predetermined male animal from the same dose group. The animals were paired by placing the female in the cage of the male mating partner from about 4.00 p.m. until 7.00 - 9.00 a.m. of the following morning. Deviations from the specified times were possible on weekends and public holidays and were reported in the raw data. 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 was detected was denoted "day 0" and the following day "day 1" post coitum.

Analytical verification of doses or concentrations:

yes

Details on analytical verification of doses or concentrations:

The stability of the test substance in drinking water for a period of up to 4 hours at room temperature was verified.

Frequency of treatment:

Daily

Details on study schedule:

The test substance was administered orally via gavage to the F0 generation parental animals daily, at approximately at the same time in the morning(exception: no administration to animals being in labor). The treatment lasted up to one day prior to sacrifice. The animals of the control group were treated in the same way with the vehicle only (drinking water). The calculation of the volume administered was generally based on the most recent
individual body weights. At least 13 days after the beginning of treatment, males and females from the same dose group were mated overnight in a ratio of 1:1 (see details on mating procedure). All F0 males were sacrificed under Isoflurane anesthesia on study day 35 followed by necropsy. The females were allowed to litter and rear their pups until day 4 after parturition. F0 females were sacrificed under Isoflurane anesthesia on study day 49/56 followed by necropsy.

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:

10 animals per sex per dose

Control animals:

yes, concurrent vehicle

Details on study design:

Doses were selected according to a preceding subacute rat study were the same doses were applied over 4 weeks by gavage.

Parental animals: Observations and examinations:

DETAILED CLINICAL OBSERVATIONS: Yes
A cageside examination was conducted daily before and about 1 hour after application for any signs of morbidity, pertinent behavioral changes and signs of overt toxicity. Abnormalities and changes were documented for each animal.

The littering and lactation behavior of the dams was generally evaluated in the mornings in combination with the daily clinical inspection of the dams. Only particular findings (e.g., animal could not litter, umbilical cord not cut) were documented on an individual dam basis.
On weekdays (except public holidays) the littering behavior of the dams was inspected in the afternoons in addition to the evaluations in the mornings.
The day of littering was considered to be the 24-hour period from about 3.00 p.m. of one day until about 3.00 p.m. of the following day.

BODY WEIGHT: Yes
In general, the body weight of the male and female parental animals was determined once a week at the same time of the day (in the morning).
The body weight change of the animals was calculated from these results.
The following exceptions are notable for the female animals:
• During the mating period the parental females were weighed on the day of positive evidence of sperm (day 0 post coitum) and on days 7, 14 and 20 post coitum.
• Females with litter were weighed on the day of parturition (day 0 post partum) and on day4 post partum.

FOOD CONSUMPTION: Yes
Generally, food consumption was determined once a week (in a period of 7 or 6 days resp.) for male and female parental animals, with the following exceptions:
• Food consumption was not determined during the mating period (male and female F0
animals).
• Food consumption of the F0 females with evidence of sperm was determined on days 0,
7, 14 and 20 post coitum.
• Food consumption of F0 females, which gave birth to a litter was determined on days 0
and 4 post partum.
Food consumption was not determined in females without positive evidence of sperm (during the mating period of dams used in parallel) and females without litter (during the lactation period of dams used in parallel).

WATER CONSUMPTION : No

Sperm parameters (parental animals):

The following parameters were determined:
• sperm motility
• sperm morphology
• sperm head count (cauda epididymis)
• sperm head count (testis)
Sperm motility examinations and the preparation of the specimens for sperm morphology were carried out in a randomized sequence. Sperm morphology and sperm head count (cauda epididymis and testis) were evaluated forthe control and highest dose group, only.

Litter observations:

Pup number and status of delivery; pup viability/mortality; sex ratio, pup clinical observations, pup body weight data

Postmortem examinations (parental animals):

Gross pathological examination:
- Gross pathological examination was performed for all females and males at necrosy.
HISTOPATHOLOGY / ORGAN WEIGHTS
- Organ weights: Testes, Epididymides, Ovaries
- The following organs were fixed: all gross lesions, pituitary gland, prostate gland, seminal vesicles with coagulation glands, uterus, oviducts, cervix uteri, vagina, left testis, left epididymis, ovaries
Histopathological examination: all gross lesions, left testis, lefr epididymis, ovaries (all animals of the control and high dose group)

Postmortem examinations (offspring):

All surviving pups (after sacrifice on day 4 post partum by means of CO2), 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.

Reproductive indices:

Reproductive indices:
- female and male mating index
- male and female fertility index
- gestation index

Offspring viability indices:

live birth index
post implantation loss
sex ratio

Clinical signs:

no effects observed

Body weight and weight changes:

no effects observed

Food consumption and compound intake (if feeding study):

no effects observed

Organ weight findings including organ / body weight ratios:

no effects observed

Histopathological findings: non-neoplastic:

no effects observed

Reproductive function: sperm measures:

no effects observed

Reproductive performance:

no effects observed

Dose descriptor:

NOAEL

Effect level:

1 000 mg/kg bw/day

Sex:

male/female

Basis for effect level:

other: general, systemic toxicity

Dose descriptor:

NOAEL

Effect level:

1 000 mg/kg bw/day

Sex:

male/female

Basis for effect level:

other: reproductive performance and fertility

Clinical signs:

no effects observed

Mortality / viability:

no mortality observed

Body weight and weight changes:

no effects observed

Organ weight findings including organ / body weight ratios:

not examined

Gross pathological findings:

no effects observed

Histopathological findings:

not examined

Dose descriptor:

NOAEL

Generation:

F1

Effect level:

1 000 mg/kg bw/day

Sex:

male/female

Basis for effect level:

other: developmental toxicity

Reproductive effects observed:

not specified

Executive summary:

Under the conditions of this reproduction/developmental toxicity screening test (OECD TG 421, gavage) the NOAEL (no observed adverse effect level) for reproductive performance and fertility is 1000 mg/kg body weight/day for the F0 parental rats. The NOAEL for general, systemic toxicity of the test substance was 1000 mg/kg body weight/day for the F0 parental animals. The NOAEL for developmental toxicity in the F1 progeny of the test-substance treated groups was found to be 1000 mg/kg body weight/day.

Reference 2

Endpoint:

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

Type of information:

experimental study planned (based on read-across)

Justification for type of information:

TESTING PROPOSAL ON VERTEBRATE ANIMALS
NON-CONFIDENTIAL NAME OF SUBSTANCE:
- Ethane- 1,2-diol, propoxylated
CONSIDERATIONS THAT THE GENERAL ADAPTATION POSSIBILITIES OF ANNEX XI OF THE
REACH REGULATION ARE NOT ADEQUATE TO GENERATE THE NECESSARY INFORMATION
[please address all points below]:
- Available GLP studies: none available
- Available non-GLP studies: none available
- Historical human data: none available
- (Q)SAR: QSAR is not an appropriate method to address the Extended One-Generation Reproductive Toxicity endpoint
- In vitro methods: none available to address the Extended One-Generation Reproductive Toxicity endpoint
- Weight of evidence: this substance is part of a broader category and has been identified as one of the substances for which data will be generated to support the broader read-across
- Grouping and read-across: this substance is part of a broader category and has been identified as one of the substances for which data will be generated to support the broader read-across
- Substance-tailored exposure driven testing [if applicable]: technically not possible due to potential exposure to the substance
- Approaches in addition to above [if applicable]: not applicable
- Other reasons [if applicable]: not applicable

CONSIDERATIONS THAT THE SPECIFIC ADAPTATION POSSIBILITIES OF ANNEXES VI TO X
(AND COLUMN 2 THEREOF) OF THE REACH REGULATION ARE NOT ADEQUATE TO GENE
RATE THE NECESSARY INFORMATION:
- At over 1000 tons the Extended One-Generation Reproductive Toxicity study is a mandatory requirement. The substance is not classified as a Category 1 carcinogen or mutagen nor is it classified for reproductive toxicity already. In addition, although the substance has a very low order of toxicity, it is not possible to rule out the potential for systemic exposure or potential human exposure, therefore it is not possible to waive in accordance with Column 2.

FURTHER INFORMATION ON TESTING PROPOSAL IN ADDITION TO INFORMATION PROVIDED
IN THE MATERIALS AND METHODS SECTION:
- Details on study design / methodology proposed [if relevant]: Extended One-Generation Reproductive Toxicity Study, Cohorts 1A and 1B without extension, in the rat in accordance with OECD 443. The pre-mating period will be 10 weeks.

Qualifier:

according to guideline

Guideline:

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

Justification for study design:

TESTING PROPOSAL ON VERTEBRATE ANIMALS
NON-CONFIDENTIAL NAME OF SUBSTANCE:
- Ethane- 1,2-diol, propoxylated
CONSIDERATIONS THAT THE GENERAL ADAPTATION POSSIBILITIES OF ANNEX XI OF THE
REACH REGULATION ARE NOT ADEQUATE TO GENERATE THE NECESSARY INFORMATION
[please address all points below]:
- Available GLP studies: none available
- Available non-GLP studies: none available
- Historical human data: none available
- (Q)SAR: QSAR is not an appropriate method to address the Extended One-Generation Reproductive Toxicity endpoint
- In vitro methods: none available to address the Extended One-Generation Reproductive Toxicity endpoint
- Weight of evidence: this substance is part of a broader category and has been identified as one of the substances for which data will be generated to support the broader read-across
- Grouping and read-across: this substance is part of a broader category and has been identified as one of the substances for which data will be generated to support the broader read-across
- Substance-tailored exposure driven testing [if applicable]: technically not possible due to potential exposure to the substance
- Approaches in addition to above [if applicable]: not applicable
- Other reasons [if applicable]: not applicable

CONSIDERATIONS THAT THE SPECIFIC ADAPTATION POSSIBILITIES OF ANNEXES VI TO X
(AND COLUMN 2 THEREOF) OF THE REACH REGULATION ARE NOT ADEQUATE TO GENE
RATE THE NECESSARY INFORMATION:
- At over 1000 tons the Extended One-Generation Reproductive Toxicity study is a mandatory requirement. The substance is not classified as a Category 1 carcinogen or mutagen nor is it classified for reproductive toxicity already. In addition, although the substance has a very low order of toxicity, it is not possible to rule out the potential for systemic exposure or potential human exposure, therefore it is not possible to waive in accordance with Column 2.

FURTHER INFORMATION ON TESTING PROPOSAL IN ADDITION TO INFORMATION PROVIDED
IN THE MATERIALS AND METHODS SECTION:
- Details on study design / methodology proposed [if relevant]: Extended One-Generation Reproductive Toxicity Study, Cohorts 1A and 1B without extension, in the rat in accordance with OECD 443. The pre-mating period will be 10 weeks.

Reproductive effects observed:

not specified

Effect on fertility: via oral route

Endpoint conclusion:

no adverse effect observed

Dose descriptor:

NOAEL

1 000 mg/kg bw/day

Study duration:

subacute

Species:

rat

Quality of whole database:

The available information comprises an adequate and reliable (Klimisch score 1) reproductive/developmental toxicity study performed with the analogue substance propylidynetrimethanol, ethoxylated. Moreover, an extended one-generation reproductive toxicity study with the analogue substance ethane- 1,2-diol, propoxylated has been proposed. The decision on the testing proposal is pending. The studies are thus sufficient to fulfil the standard information requirements set out in Annexes VIII - X, Section 8.7., of Regulation (EC) No. 1907/2006 (REACH).

Effect on fertility: via inhalation route

Endpoint conclusion:

no study available

Effect on fertility: via dermal route

Endpoint conclusion:

no study available

Additional information

No data on reproductive toxixity for propylidentrimethanol, propoxylated (CAS No. 25723-16-4, EC No. 500-041-9) are available. Therefore, data obtained with the analogue substance propylidynetrimethanol, ethoxylated (CAS No. 50586-59-9, EC No. 500-110-3) are used in a read across approach. Toxicity to reproduction of propylidynetrimethaol, ethoxylated was investigated in a reproductive/developmental toxicity screening study according to OECD guideline 421 under GLP conditions (rel 1-key, rat, gavage, OECD 421, BASF, 2010, AT02642). Groups of 10 Wistar rats per sex were dosed with 100, 300 and 1000 mg/kg bw/day by oral gavage. Since no toxicologically relevant effects were observed, the no-observed-adverse-effect level (NOAEL) for reproductive performance and fertility was found to be 1000 mg/kg bw/day for the F0 parental rats. The NOAEL for general, systemic toxicity of the test substance was 1000 mg/kg bw/day for the F0 parental animals. The NOAEL for developmental toxicity in the F1 progeny of the test substance-treated groups was found to be 1000 mg/kg bw/day.

 

Moreover, an extended one-generation reproductive toxicity study (EOGRTS) according to OECD guideline 443 in the rat by the oral route of exposure with the analogue substance ethane-1,2-diol, propoxylated (CAS No.31923-84-9, EC No. 500-078-0) has been proposed. The decision on the testing proposal is pending. A dossier update will be submitted containing the results of the EOGRTS following an appropriate decision by ECHA. Based on the results of the EOGRTS, the hazard assessment with respect to reproductive toxicity will be concluded.

Effects on developmental toxicity

Description of key information

Pre-natal development (OECD 414, oral, rat): NOAEL (maternal toxicity) = 1000 mg/kg bw/day; NOAEL (development) = 1000 mg/kg bw/day

Pre-natal development (OECD 414, oral, rabbit): NOAEL (maternal toxicity) = 400 mg/kg bw/day; NOAEL (development) = 400 mg/kg bw/day

Link to relevant study records

Reference

Reference 1

Endpoint:

developmental toxicity

Type of information:

experimental study

Adequacy of study:

key study

Study period:

08 Apr - 25 May 2020

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:

yes

Remarks:

No histopathological examination of thyroid performed.

GLP compliance:

yes (incl. QA statement)

Remarks:

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

Limit test:

no

Specific details on test material used for the study:

Propylidyntrimethanol, propoxylated; UVCB

Species:

rat

Strain:

other: Han Wistar RccHan®:WIST

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Source: Envigo RMS (UK) Limited, Shaw’s Farm, Blackthorn, Bicester, Oxon, UK
- Age at study initiation: 9 - 11 weeks
- Weight at study initiation: 177 - 246 g
- Housing: 3 per cage in polycarbonate cages with stainless steel grid tops, solid bottoms and sterilised white wood shavings as bedding material.
- Diet: VRF-1 breeder diet (SDS, Witham, Essex, UK), ad libitum
- Water: Water from public supply, ad libitum
- Acclimation period: From arrival until start of dosing, i.e. a minimum of 5 days

ENVIRONMENTAL CONDITIONS
- Temperature (°C): 20 - 23
- Humidity (%): 44 - 65
- Air changes (per hr): >= 10
- Photoperiod (hrs dark / hrs light): 12 / 12

IN-LIFE DATES: From: 14 Apr To: 07 May 2020

Route of administration:

oral: gavage

Vehicle:

water

Details on exposure:

PREPARATION OF DOSING SOLUTIONS:
Dosing solutions were prepared weekly by weighing the required amount of test item and adding the required amount of the vehicle water (w/w). The final concentrations of test item in the vehicle were 10, 30 and 100 mg/mL.

VEHICLE
- Substance: Milli-Q Water (purified in house)

Analytical verification of doses or concentrations:

yes

Details on analytical verification of doses or concentrations:

Duplicate top, middle and bottom samples (duplicate middle only for control) were collected for concentration and homogeneity analyses. When only concentration analysis was required, the formulations were only sampled from the middle. Concentration results were considered acceptable if they were within or equal to ± 15% of theoretical concentration. Each individual sample concentration result was considered acceptable if it was within or equal to ± 20%. Homogeneity results were considered acceptable if the relative standard deviation of the mean value at each sampling location was <= 10%. The analyses confirmed the concentration, stability and homogeneity of the dosing formulations.

Details on mating procedure:

- Impregnation procedure: purchased timed pregnant
- Proof of pregnancy: vaginal plug referred to as day 0 of pregnancy

Duration of treatment / exposure:

Day 6 - 20 of gestation

Frequency of treatment:

daily, 7 days/week

Duration of test:

Until Day 20 of gestation

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:

24 females

Control animals:

yes, concurrent vehicle

Details on study design:

- Dose selection rationale: Dose levels were based on the results of a foregoing preliminary prenatal developmental toxicity study in which animals were orally exposed to 100, 300 and 1000 mg/kg bw/day from GD 6 to GD 20 (Charles River, 2020, study no. 490513). In the absence of any maternal toxicity findings, 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: Twice daily throughout the study for general health/mortality and moribundity.

DETAILED CLINICAL OBSERVATIONS: Yes
- Time schedule: Once during pretreatment on GD 3 and weekly during the dosing period from GD 6.

BODY WEIGHT: Yes
- Time schedule for examinations: GD 0 (provided by the supplier), GD 3, GD 6, GD 9, GD 12, GD 15, GD 18 and GD 21.

FOOD CONSUMPTION: Yes
- Time schedule: GD 3 - 6, GD 6 - 9, GD 9 - 12, GD 12 - 15, GD 15 - 18 and GD 18 - 21

WATER CONSUMPTION: Yes
- Time schedule for examinations: Water consumption was monitored by visual inspection of the water bottles only. No quantitative analysis was performed.

POST-MORTEM EXAMINATIONS: Yes
- Sacrifice on gestation day 21
- Organs / tissues examined: Thyroid gland (with parathyroid), ovary, oviduct, uterus/cervix/vagina, placentae

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
- Other: Apparent non-pregnant uteri were retained, stained and examined for implantation sites.

Fetal examinations:

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

Statistics:

Means, standard deviations, percentages, numbers, and/or incidences have been reported, as appropriate by dataset. Inferential statistical tests were conducted at the 5% significance level. All pairwise comparisons were conducted using two sided tests and have been reported at the 1% and 5% levels, unless otherwise noted. Analyses were performed excluding any group with less than 3 observations.
Parametric/Non-parametric: Levene’s test was used to assess the homogeneity of group variances. The groups were compared using an overall one-way ANOVA F-test if Levene’s test was not significant or the Kruskal-Wallis test if it was significant. If the overall F-test or Kruskal Wallis test was found to be significant, then pairwise comparisons were conducted using Dunnett’s or Dunn’s test, respectively.
Non-parametric: The groups were compared using an overall Kruskal-Wallis test. If the overall Kruskal-Wallis test was found to be significant, then the above pairwise comparisons were conducted using Dunn’s test.
Incidence: A Fisher’s exact test was used to conduct pairwise group comparisons of interest.

Indices:

Pregnancy Rate = (No. of animals pregnant / No. of animals mated at the supplier) x 100

Pre-Implantation Loss = [(No. of corpora lutea – No. of implants) / No. of corpora lutea] x 100

Post-Implantation Loss = [(No. of implants – No. of live fetuses) / No. of implants] x 100

Sex Ratio (% males) = (No. male fetuses / Total No. of fetuses) x 100

Litter % of Fetuses with Abnormalities = (No. of fetuses in litter with a given finding / No. of fetuses in litter examined) x 100

Clinical signs:

effects observed, treatment-related

Description (incidence and severity):

9/23 animals in the high-dose group showed ploughing of the cage shavings from GD 15 onwards. This was transient and was seen immediately following dose administration only. Abnormal gait and hunched posture were observed in 2/24 animals on GD 7 or GD 8. One of these 2 animals was euthanised on GD 7 and showed decreased respiratory rate, hunched posture, eyes partly closed, uncoordinated and abnormal gait, subdued, cold to touch and head twitches as additional clinical signs. Further minor clinical observations were not treatment-related based on the type and distribution, e.g. fur thinning, and scabbing are commonly observed in rats and were therefore considered normal background findings. Increased activity was seen once in 1 animal of the low-dose group. Based on the single incidence and absence of dose response, this was considered sporadic.

Dermal irritation (if dermal study):

not examined

Mortality:

mortality observed, non-treatment-related

Description (incidence):

One animal of the high-dose group was euthanised on GD 7 after receiving 2 doses due to the onset of adverse clinical signs at 1 - 2 h post dose administration. At necropsy, there were no abnormalities noted. The animal was not pregnant.

Body weight and weight changes:

no effects observed

Food consumption and compound intake (if feeding study):

effects observed, non-treatment-related

Description (incidence and severity):

A significant increase in food consumption in the high-dose group on GD 9 - 15 was observed. This was considered not treatment-related.

Food efficiency:

not examined

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

not examined

Description (incidence and severity):

Water consumption was not analysed quantitatively.

Ophthalmological findings:

not examined

Haematological findings:

not examined

Clinical biochemistry findings:

effects observed, non-treatment-related

Description (incidence and severity):

Maternal thyroid hormone levels (T3, T4 and TSH) on GD 21 were comparable between all groups. Slight intergroup differences did not follow a dose-related pattern and were too small to be considered treatment-related.

Urinalysis findings:

not examined

Behaviour (functional findings):

not examined

Immunological findings:

not examined

Organ weight findings including organ / body weight ratios:

no effects observed

Gross pathological findings:

no effects observed

Neuropathological findings:

not examined

Histopathological findings: non-neoplastic:

no effects observed

Histopathological findings: neoplastic:

not examined

Number of abortions:

no effects observed

Pre- and post-implantation loss:

effects observed, non-treatment-related

Description (incidence and severity):

The mean pre- and post implantation losses were higher in the mid-dose group when compared to the controls. However, as there was no dose relationship, this was considered incidental.

Total litter losses by resorption:

no effects observed

Early or late resorptions:

no effects observed

Dead fetuses:

no effects observed

Changes in pregnancy duration:

no effects observed

Changes in number of pregnant:

effects observed, non-treatment-related

Description (incidence and severity):

4, 4 and 2 animals were found to be not pregnant in the low-, mid- and high-dose groups, respectively. As there was no dose relationship, these non pregnancies were considered sporadic and unrelated to administration of the test substance.

Details on maternal toxic effects:

Additional details on results are provided in the pdf document 'Summary tables' under 'Attached background material'.

Key result

Dose descriptor:

NOAEL

Remarks:

maternal

Effect level:

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

Based on:

test mat.

Basis for effect level:

other: no biologically relevant effects observed

Key result

Abnormalities:

no effects observed

Fetal body weight changes:

not examined

Reduction in number of live offspring:

no effects observed

Changes in sex ratio:

no effects observed

Changes in litter size and weights:

no effects observed

Changes in postnatal survival:

not examined

External malformations:

no effects observed

Skeletal malformations:

no effects observed

Visceral malformations:

no effects observed

Other effects:

effects observed, non-treatment-related

Description (incidence and severity):

In the high-dose group, the litter mean anogenital distance (AGD) was lower by 12% in male fetuses (2.90 mm vs. 3.28 mm in the controls) and by 16% in female fetuses (1.26 mm vs. 1.50 mm in the controls). However, the differences in absolute values were small, the mean AGD was within the standard deviation for the control group and within the test facility’s control values from similar assessments. Therefore, the AGD was considered to be within normal variation for all groups. There was no evidence of an effect on fetal weights.

Details on embryotoxic / teratogenic effects:

Additional details on results are provided in the pdf document 'Summary tables' under 'Attached background material'.

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 biologically relevant effects observed

Key result

Developmental effects observed:

no

Additional details on results are provided in the pdf document 'Summary tables' under 'Attached background material'.

Conclusions:

Propylidynetrimethanol, propoxylated did not exert any maternal systemic toxicity and had no effect on intrauterine development when administered at doses of up to 1000 mg/kg bw/day by oral gavage to pregnant rats on GD 6 - GD 20. Additional details on results are provided in the pdf document 'Summary tables' under 'Attached background material'.

Reference 2

Endpoint:

developmental toxicity

Type of information:

experimental study

Adequacy of study:

key study

Study period:

07 Dec 2020

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 2018

Deviations:

no

Qualifier:

according to guideline

Guideline:

EPA OPPTS 870.3700 (Prenatal Developmental Toxicity Study)

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, UK

Limit test:

no

Specific details on test material used for the study:

Propylidyntrimethanol, propoxylated; UVCB

Species:

rabbit

Strain:

New Zealand White

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Source: Envigo RMS (UK) Limited, Shaw’s Farm, Blackthorn, Bicester, Oxon, UK
- Age at study initiation: 4 - 7 months
- Weight at study initiation: 2.8 - 3.9 kg
- Housing: Single, appropriately sized stainless steel cages with a ‘Noryl’ dual level interior and perforated floor; cages also contained suitable objects for chewing and devices for hiding in.
- Diet: Envigo diet (pellets) and a small portion of a limited selection of fruits and/or vegetables (up to twice per study week), ad libitum
- Water: Water from public supply, ad libitum
- Acclimation period: From arrival until start of dosing, i.e. a minimum of 5 days

ENVIRONMENTAL CONDITIONS
- Temperature (°C): 18 - 19
- Humidity (%): 51 - 62
- Air changes (per hr): >= 10
- Photoperiod (hrs dark / hrs light): 12 / 12

IN-LIFE DATES: From: 11 Dec 2020 To: 15 Jan 2021

Route of administration:

oral: gavage

Vehicle:

water

Details on exposure:

PREPARATION OF DOSING SOLUTIONS:
Dosing solutions were prepared weekly by weighing the required amount of test item and adding the required amount of the vehicle water (w/w). The final concentrations of test item in the vehicle were 5, 20 and 40 mg/mL.

VEHICLE
- Substance: Milli-Q Water (purified in house)
- Amount of vehicle (if gavage): 10 mL/kg bw
- Density: 1.04 g/mL
- Storage conditions: Ambient temperature

Analytical verification of doses or concentrations:

yes

Details on analytical verification of doses or concentrations:

Duplicate top, middle and bottom samples (duplicate middle only for control) were collected for concentration and homogeneity analyses. When only concentration analysis was required, the formulations were only sampled from the middle. Concentration results were considered acceptable if they were within ± 15% of the theoretical concentration. Each individual sample concentration result was considered acceptable if it was within ± 20% of the theoretical concentration. Homogeneity results were considered acceptable if the relative standard deviation of the mean value at each sampling location was <= 10%. The analyses confirmed the concentration, stability and homogeneity of the dosing formulations.

Details on mating procedure:

- Impregnation procedure: purchased timed pregnant

Duration of treatment / exposure:

Day 6 - 28 of gestation (where GD 0 was the day of mating)

Frequency of treatment:

daily, 7 days/week

Duration of test:

Until Day 28 of gestation

Dose / conc.:

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

Dose / conc.:

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

Dose / conc.:

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

No. of animals per sex per dose:

24 females

Control animals:

yes, concurrent vehicle

Details on study design:

- Dose selection rationale: Dose levels were based on the results of a foregoing preliminary prenatal developmental toxicity study in which non-pregnant and pregnant New Zealand White rabbits were orally exposed to 200, 500, 750 and 1000 mg/kg bw/day (Charles River, 2020, study no. 490445). Based on findings at 500 mg/kg bw/day (abnormal respiration, uncoordinated behaviour, abnormal gait as well as higher pre-implantation and post-implantation losses), 400 mg/kg bw/day was selected as the high-dose for the main study, with low- and mid-dose levels of 50 and 200 mg/kg bw/day, respectively.

Maternal examinations:

CAGE SIDE OBSERVATIONS: Yes
- Time schedule: At least once daily (twice daily for mortality) from arrival throughout the study.

DETAILED CLINICAL OBSERVATIONS: Yes
- Time schedule: Once during pretreatment on Gestation Day (GD) 5 and weekly during the dosing period from GD 6.

INDIVIDUAL BODY WEIGHT: Yes
- Time schedule for examinations: Daily starting on GD 4 throughout the study until scheduled necropsy.

FOOD CONSUMPTION: Yes
- Time schedule: Daily starting on GD 5 throughout the study.

POST-MORTEM EXAMINATIONS: Yes
- Sacrifice on gestation day 29
- Organs / tissues examined: Thyroid gland (with parathyroid), carcass and musculoskeletal system, all external surfaces and orifices; cranial cavity and external surfaces of the brain; thoracic, abdominal, and pelvic cavities with their associated organs and tissues; the reproductive tract was dissected and weighed intact.

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
- Skeletal examinations: Yes: half per litter
- Head examinations: Yes: half per litter
- other: Histology: Thyroid gland (with parathyroid) was examined in all fetuses

Statistics:

Means, standard deviations, percentages, numbers, and/or incidences have been reported as appropriate by dataset. All statistical tests were conducted at the 5% significance level. All pairwise comparisons were conducted using two sided tests and have been reported at the 1% and 5% levels. A Fisher’s exact test was used to conduct pairwise group comparisons of interest.
Parametric/Non-parametric: Levene’s test was used to assess the homogeneity of group variances. The groups were compared using an overall one-way ANOVA F-test if Levene’s test was not significant or the Kruskal-Wallis test if it was significant. If the overall F-test or Kruskal Wallis test was found to be significant, then pairwise comparisons were conducted using Dunnett’s or Dunn’s test, respectively.
Non-Parametric: The groups were compared using an overall Kruskal-Wallis test. If the overall Kruskal-Wallis test was found to be significant, then pairwise comparisons were conducted using Dunn’s test.

Indices:

Pregnancy Rate = (No. of animals pregnant / No. of animals mated at the supplier) x 100

Pre-Implantation Loss = [(No. of corpora lutea – No. of implants) / No. of corpora lutea] x 100

Post-Implantation Loss = [(No. of implants – No. of live fetuses) / No. of implants] x 100

Sex Ratio (% males) = (No. male fetuses / Total No. of fetuses) x 100

Litter % of Fetuses with Abnormalities = (No. of fetuses in litter with a given finding / No. of fetuses in litter examined) x 100

Clinical signs:

effects observed, treatment-related

Description (incidence and severity):

400 mg/kg bw/day: Uncoordination, increased respiration rate and decreased activity was observed in all animals. During GD 6 and 7, increased respiration lasted up to 1-2 h post dose in all animals. This observation then reduced to generally 0-1 h post dose up to and including GD 13. Uncoordination was noted to last up to 3 h post dose during the first day of dosing. This was reduced to 2 h post dose up to and including GD 11. Decreased activity was noted to last up to 1-2 h after dosing during GD 6 and 7 and reduced to 0-1 h post dose up to and including GD 11. These findings were of transient nature, decreasing over time in duration and intensity with repeating dosages. After one week of treatment, they nearly fully disappeared, only occurring sporadically until GD 20 (non-adverse).
200 mg/kg bw/day: Effects noticed at this dose level were similar to those seen in the high dose group. The findings here also were transient in nature and they fully disappeared within one week of treatment (non-adverse).
Control group: Darkened eyes, shallow respiration, decreased activity and uncoordinated movements were observed at the 0-1 h post dose check for the female that died on GD 28. No clinical signs of toxicity were observed for any other animals in the control group.

Dermal irritation (if dermal study):

not examined

Mortality:

mortality observed, non-treatment-related

Description (incidence):

Two females of the control group died due to misgavage on GD 17 and 28, respectively. No mortalities were noticed in the treated groups.

Body weight and weight changes:

no effects observed

Food consumption and compound intake (if feeding study):

effects observed, non-treatment-related

Description (incidence and severity):

400 mg/kg bw/day: A lower mean food consumption of up to -21% was recorded throughout dosing with the exception of GD 22-23 and GD 28-29 when compared with the control. This was likely due to sporadic low food consumption of single animals in this group throughout the dosing period as the low consumption did not correlate with any body weight or bodyweight gains (non-adverse).

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

Endocrine 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

Gross pathological findings:

no effects observed

Neuropathological findings:

not examined

Histopathological findings: non-neoplastic:

no effects observed

Histopathological findings: neoplastic:

not examined

Number of abortions:

no effects observed

Pre- and post-implantation loss:

effects observed, non-treatment-related

Description (incidence and severity):

In all dose groups there were higher pre-implantation losses of 11.13 (246.83%), 11.47 (257.23%) and 8.21 (155.69%) at 50, 200 and 400 mg/kg bw/day, respectively, when compared with the controls (3.21). In fact, each treated group beared some individual animals with obviously increased pre-implantation loss rates as compared to the others as well as to the control range (minimum, 0.0; maximum, 14.3). Since no dose-related pattern could be evidenced and since the differences still were within normal biological variation, the findings were not considered treatment-related.

Total litter losses by resorption:

no effects observed

Early or late resorptions:

no effects observed

Dead fetuses:

effects observed, non-treatment-related

Description (incidence and severity):

At 200 mg/kg bw/day there was a statistically significant decrease in mean number of live fetuses of 6.6 (-23.8%) when compared with the controls of 8.7. In fact, the test group beared some individual animals with comparatively lower numbers of live fetuses as compared to the others. Furthermore, since no such observation was made at 50 and 400 mg/kg bw/day, no dose-related pattern could be evidenced and the finding was not considered treatment-related.

Changes in pregnancy duration:

no effects observed

Changes in number of pregnant:

no effects observed

Key result

Dose descriptor:

NOAEL

Remarks:

maternal

Effect level:

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

Based on:

test mat.

Basis for effect level:

other: no biologically relevant effects observed

Key result

Abnormalities:

no effects observed

Fetal body weight changes:

not examined

Reduction in number of live offspring:

no effects observed

Changes in sex ratio:

no effects observed

Changes in litter size and weights:

effects observed, non-treatment-related

Description (incidence and severity):

At 200 mg/kg bw/day there were statistically significant mean lower numbers of implantations of 7.8 (-19.0%) and mean total number of fetuses of 6.6 (-23.8%) when compared with the controls of 9.6 and 8.7, respectively. In fact, the test group beared some individual animals with comparatively lower numbers of implantations and number of fetuses as compared to the others. Furthermore, since no such observation was made at 50 and 400 mg/kg bw/day, no dose-related pattern could be evidenced and the finding was not considered treatment-related.

Anogenital distance of all rodent fetuses:

not examined

Changes in postnatal survival:

not examined

External malformations:

no effects observed

Skeletal malformations:

no effects observed

Visceral malformations:

no effects observed

Key result

Dose descriptor:

NOAEL

Remarks:

development

Effect level:

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

Based on:

test mat.

Sex:

male/female

Basis for effect level:

other: no biologically relevant effects observed

Key result

Developmental effects observed:

no

Additional details on results are provided in the pdf document under 'Attached background material'.

Conclusions:

Once daily oral gavage administration of propylidynetrimethanol, propoxylated at doses of 50, 200 and 400 mg/kg bw/day to pregnant rabbits on GD 6-29 induced clinical signs in maternal animals. Uncoordinated, increased respiration rate and decreased activity were observed at the mid- and high-dose level; no such findings were reported for the low-dose group. However, these findings were transient in nature, decreasing over time in duration and intensity with repeating dosages; they almost disappeared after one week of treatment. Therefore, they were not considered to be adverse. Additional details on results are provided in the pdf document 'Summary tables' under 'Attached background material'.

Effect on developmental toxicity: via oral route

Endpoint conclusion:

no adverse effect observed

Dose descriptor:

NOAEL

400 mg/kg bw/day

Study duration:

subacute

Species:

rabbit

Quality of whole database:

The available information comprises adequate and reliable (Klimisch score 1) studies performed with the registered substance. The selected studies are thus sufficient to fulfil the standard information requirements set out in Annexes VIII - X, Section 8.7., 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

Developmental toxicity / teratogenicity in rats

Potential effects of propylidentrimethanol, propoxylated (CAS No. 25723-16-4, EC No. 500-041-9) on pre-natal development were examined in a study conducted according to OECD guideline 414 under GLP conditions (rel 1-key, rat, gavage, OECD 414, Charles River, 2020b, 490529). The test substance was administered once daily by oral gavage to groups of 24 pregnant Han Wistar RccHan®:WIST rats in doses of 100, 300 and 1000 mg/kg bw/day. The animals of the control group received the vehicle (water) only. Animals were dosed during the critical phase of organogenesis, i.e. on gestation days (GD) 6 - 20. The following parameters were evaluated: clinical observations, body weights, gravid uterus weights and corrected body weights, food consumption, clinical pathology parameters (thyroid stimulating hormone [TSH], T3 and T4), gross necropsy, organ weights (thyroid), maternal performance, ovarian and uterine findings and fetal examinations (body weights, sex, anogenital distance, external abnormalities, fixed head examinations, visceral examinations and skeletal examinations).

In the dams, administration of the test substance at 1000 mg/kg bw/day was associated with transient ploughing following dose administration, which was considered not adverse. One animal given 1000 mg/kg bw/day, was euthanised due to clinical signs at 1 - 2 h following dose administration on GD 7 (decreased respiratory rate, hunched posture, partly closed eyes, uncoordinated and abnormal gait, subdued, cold to touch, and head twitches). The cause of this animal’s condition was unknown. Abnormal gait and hunched posture were seen in one other animal given 1000 mg/kg bw/day (GD 8, 0 - 1 h post dose only), but based on the single occurrence and transient nature, this was considered incidental. Given the lack of adverse findings in any other animal, the moribund condition of the unscheduled decedent was considered unlikely to be related to treatment with the test substance. For all other parameters, there were no test substance-related changes. In conclusion, administration of propylidentrimethanol, propoxylated by once daily oral gavage to pregnant rats was tolerated with no changes in maternal food consumption, body weight gains or thyroid hormone levels. Examination of pregnancies did not reveal any effect of the test substance on implantation, embryofetal survival, anogenital distance and fetal or placental weights. There were no relevant fetal morphology changes. Based on these results, the no-observed-adverse-effect Level (NOAEL) for maternal toxicity and fetal development was considered to be the high dose level of 1000 mg/kg bw/day.

Developmental toxicity / teratogenicity in rabbits

The potential toxicity of propylidentrimethanol, propoxylated (CAS No. 25723-16-4, EC No. 500-041-9) on embryofetal development when given to pregnant rabbits by gavage from Gestation Day (GD) 6 to 28 was investigated in a GLP-conform study conducted according to OECD guideline 414 (rel 1-key, rabbit, gavage, OECD 414, Charles River, 2021, 490466). Groups of 24 time-mated female New Zealand White rabbits were exposed to the test substance at doses of 50, 200 and 400 mg/kg bw/day by daily gavage on 7 days per week. The control group was treated with the vehicle (water). Animals were dosed during the critical phase of organogenesis, i.e. on GD 6-28. The following parameters were evaluated in the study: clinical observations, body weights, gravid uterus weights and corrected body weights, food consumption, maternal performance, examination of pregnancies on GD 29, fetal examinations (body weights, sex, external, visceral and skeletal examinations and the extent of ossification), thyroid weights and macroscopic and microscopic examinations of thyroids.

At 400 mg/kg bw/day there were clinical observations of uncoordinated, increased respiration rate and decreased activity. During GD 6 and 7, increased respiration lasted up to 2 h post-dose in all animals. This effect was reduced to 1 h post dose up to and including GD 13. Uncoordinated movement lasted up to 3 h post dose during the first day of dosing. This observation then reduced to 2 h post dose up to and including GD 11. Decreased activity was noted to last up to 2 h post dose during GD 6 and 7 and reduced to 1 h after dosing up to and including GD 11. At 200 mg/kg bw/day there were similar and transient observations that reduced in duration with repeat dosing and disappeared after the first week of dosing. Due to the short duration of the clinical signs, they were judged to be non-adverse in nature. There were no test substance-related effects on body weights and body weight gains, food consumption, gravid uterus and corrected body weights, macroscopic pathology, thyroid weights or microscopic examination, maternal performance and fetal data. At the dose of 50 mg/kg bw/day neither the dams nor the fetuses showed any effect related to treatment. Based on these results, the no-observed-adverse-effect level (NOAEL) for maternal toxicity and fetal development was considered to be 400 mg/kg bw/day, i.e. the highest dose tested.

Justification for classification or non-classification

The available data on developmental toxicity with propylidentrimethanol, propoxylated (CAS No. 25723-16-4, EC No. 500-041-9) in two species (rat and rabbit) do not meet the criteria for classification according to the CLP Regulation (EC) No. 1272/2008 and are therefore conclusive but not sufficient for classification. The endpoint toxicity to reproduction is covered by read-across from the analogue substance propylidentrimethanol, ethoxylated (CAS No. 50586-59-9, EC No. 500-110-3) since no study is available for the registered substance. The available data on toxicity to reproduction with propylidentrimethanol, ethoxylated do not meet the criteria for classification according to the CLP Regulation (EC) No. 1272/2008 and are therefore conclusive but not sufficient for classification. In addition, an extended one-generation reproductive toxicity study (EOGRTS) according to OECD guideline 443 in the rat by the oral route with the analogue substance ethane-1,2-diol, propoxylated (CAS No.31923-84-9, EC No. 500-078-0) has been proposed. The decision on the testing proposal is pending.

 

In conclusion, the data currently available do not provide sufficient evidence that would imply a classification for reproductive or developmental toxicity according to the CLP Regulation (EC) No. 1272/2008 and are therefore conclusive but not sufficient for classification. However, since an important study is proposed to be performed in the future, the overall conclusion for classification of propylidentrimethanol, propoxylated regarding toxicity to reproduction needs to be re-assessed as soon as further data will be available.