m-bis(2,3-epoxypropoxy)benzene

Endpoint summary

Key value for chemical safety assessment

Effects on fertility

Link to relevant study records

Reference

Endpoint:

screening for reproductive / developmental toxicity

Type of information:

experimental study

Adequacy of study:

key study

Study period:

10 April 2018 - (no data as audited draft report)

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Justification for type of information:

On 12th April 2019, Emerald submitted the Lead Registration for this substance under the DCG (Directors’ Contact Group) issue 10 as communicated to ECHA in communication INC000000227877. However, some of the screening studies for the substance were still ongoing with the CRO, and since then they have experienced further unforeseen delay in finalizing the report.
ECHA has since provided a deadline to submit the complete information as an update by the technical completeness check deadline of 30 May 2019 (Communication number: SUB-C-2114468593-38-02/F).
Unfortunately, the CRO has encountered an extended delay for the OECD 421 - Reproduction/Developmental Toxicity Screening Test in the Rat by Oral Gavage study.
In the 'Attached Justification' section as well as in section 13 of the dossier, you can find an explanatory letter from the CRO to confirm this situation and explaining therefore that the current deadline of 30th May 2019 could unfortunately not be fully met. The letter additionally includes predicted final report dates for these studies.
With regards to that, we would like to confirm that a spontaneous dossier update will be conducted as soon as data will become available.

Qualifier:

according to guideline

Guideline:

OECD Guideline 421 (Reproduction / Developmental Toxicity Screening Test)

Version / remarks:

2016

Deviations:

no

GLP compliance:

yes

Specific details on test material used for the study:

SOURCE OF TEST MATERIAL
- Source: CVC Thermoset Specialties, 844 N. Lenola Road, Moorestown, New Jersey 08057
- Lot/batch No.of test material: 53715080
- Expiration Date: 5 August 2019, when stored at ambient temperature
- Storage Conditions: Room temperature (15 to 25 °C)
- Purity: 100%

Species:

rat

Strain:

Sprague-Dawley

Sex:

male/female

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Source: Charles River Laboratories, Raleigh, North Carolina 27610
- Age at study initiation: 11 weeks males and 13 weeks female
- Weight at study initiation: Males:395 - 494 grams, Females: 27 - 315 grams
- Housing: Suspended, solid bottom cages with cellulose-based contact bedding
- Diet: ad libitum (Teklad Global 18% Protein Rodent Diet (Certified), 2018C, Envigo, Madison, Wisconsin)
- Water: ad libitum (Potable water from the public supply)
- Acclimation period: 5 days

ENVIRONMENTAL CONDITIONS
- Temperature (°C): 20 - 26
- Humidity (%): 30 - 70
- Photoperiod (hrs dark / hrs light): 12/ 12

Route of administration:

oral: gavage

Vehicle:

corn oil

Details on exposure:

VEHICLE
- Justification for use and choice of vehicle (if other than water):
- Dose (mg/kg/day): 0, 45, 90 and 180
- Concentrations in vehicle (mg/mL): 0, 9, 18 and 36
- Volume Dose (mL/ kg): 5
- Lot/batch no. (if required):
- Storage conditions: Room temperature, dry, protected from light
- Lot numbers: 2HB0068, 2GK0223
- Purity: 100%
- Expiration dates: 31 January 2019, 31 October 2018
- Fresh formulations were prepared once weekly and were stored refrigerated (2 to 8 °C) when not in use

Details on mating procedure:

- M/F ratio per cage: 1:1
- Length of cohabitation: Until evidence of mating was seen or until 14 consecutive days of cohabitation had elapsed.
- Proof of pregnancy: vaginal plug or sperm in the vaginal smear

- After 14 days of unsuccessful pairing replacement of first male by another male with proven fertility.
- Further matings after two unsuccessful attempts: no

Analytical verification of doses or concentrations:

yes

Duration of treatment / exposure:

F0 males was 2 weeks pre-cohabitation, during cohabitation (up to 3 weeks) and continuing during post-cohabitation until the day prior to termination (approximately 35 days).
F0 females was 2 weeks pre-cohabitation, cohabitation (up to 3 weeks) and during gestation and lactation continuing until LD 13 (approximately 70 days).

Dose / conc.:

0 mg/kg bw/day (nominal)

Dose / conc.:

45 mg/kg bw/day (nominal)

Dose / conc.:

90 mg/kg bw/day (nominal)

Dose / conc.:

180 mg/kg bw/day (nominal)

No. of animals per sex per dose:

10

Control animals:

yes

Details on study design:

Not specified

Positive control:

No

Parental animals: Observations and examinations:

Animals were observed in their cages at least twice daily for mortality and general condition.CAGE SIDE OBSERVATIONS:
- Time schedule: Animals were observed in their cages at least twice daily for mortality and general condition

BODY WEIGHT: Yes
- F0 male rats were recorded weekly prior to treatment initiation and prior to dosing from the initiation of treatment and weekly thereafter throughout the study and at termination.
- F0 female rats were recorded weekly prior to treatment initiation and prior to dosing, from the initiation of treatment and weekly during the pre-cohabitation and cohabitation phases until mated.
- Mated female rats were weighed on GD 0, 7, 14 and 20.
- Female rats that delivered litters were weighed on LD 1, 4, 7 and 13 and at termination on LD 14.
- Female rats without evidence of mating from the second male pairing were moved into the gestation phase and upon delivery were moved into the lactation phase and weighed similarly as other females with evidence of mating.

FOOD CONSUMPTION AND COMPOUND INTAKE (if feeding study):
- Food consumption for the male and female rats was measured (weighed) weekly prior to initiation of treatment (pretest) and during the pre-cohabitation phase.
- Food consumption was not measured during the cohabitation phase when male rats were being co-housed with female rats.
- For male rats, food consumption was measured weekly during the post-cohabitation phase.
- For female rats, gestation and lactation food consumption was measured on GDs 0-7, 7 14 and 14-20 and on LDs 1-7 and 7-14, respectively.

Oestrous cyclicity (parental animals):

Vaginal smears were obtained daily from each F0 female pretest (to determine suitability for study) and during the pre-cohabitation and cohabitation phases until mating was confirmed and the stage of estrous was determined.

Offspring viability indices:

.

Clinical signs:

effects observed, non-treatment-related

Description (incidence and severity):

There were no m-bis(2,3-epoxypropoxy)benzene-related observations in the males and females that survived until scheduled termination.
Any clinical observations noted were not considered to be treatment-related due to their common occurrence in this laboratory animal species.

Dermal irritation (if dermal study):

not specified

Mortality:

mortality observed, treatment-related

Description (incidence):

There were 14 unscheduled decedents (3 males and 11 females) over the course of this study.
Of the 11 females, 9 were euthanized due to total litter loss or failure to get pregnant.
Of the remaining 5 animals, 3 males at ≥ 90 mg/kg/day and 1 female at 45 mg/kg/day were found dead and 1 female at 90 mg/kg/day was euthanized for welfare reasons.
The cause of death/morbidity in 3 of the found dead animals was undetermined.
The remaining 2 animals dosed at 90 mg/kg/day had microscopic findings of mucosal erosion or necrosis and inflammation of the glandular or non-glandular region of the stomach that were considered to have contributed to the cause of death.

Body weight and weight changes:

effects observed, non-treatment-related

Description (incidence and severity):

There was an m-bis(2,3-epoxypropoxy)benzene-related decrease in absolute mean body weight and body weight gain in males at ≥ 90 mg/kg/day over the course of this study.
By study termination, the absolute mean body weights were -8.6% and -15.4% of that of the controls at 90 and 180 mg/kg/day, respectively.
There were no m-bis(2,3-epoxypropoxy)benzene-related effects on absolute mean body weight or body weight gain in males at 45 mg/kg/day or females at any dose tested.
Any changes noted were not considered to be related to treatment due to their small magnitude, sporadic occurrence and/or lack of relation to dose.

Food consumption and compound intake (if feeding study):

effects observed, treatment-related

Description (incidence and severity):

There was an m-bis(2,3-epoxypropoxy)benzene-related decrease in food consumption in males at ≥ 90 mg/kg/day and females at ≥ 45 mg/kg/day over the course of this study.
A maximal decrease of -26.1% and -31.6% was noted during the precohabitation phase (Day 7 - 14) for males and females, respectively.

Food efficiency:

not specified

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

not specified

Ophthalmological findings:

not specified

Haematological findings:

not specified

Clinical biochemistry findings:

not specified

Urinalysis findings:

not specified

Behaviour (functional findings):

not specified

Immunological findings:

not specified

Organ weight findings including organ / body weight ratios:

effects observed, treatment-related

Histopathological findings: non-neoplastic:

not specified

Histopathological findings: neoplastic:

not specified

Other effects:

not specified

Reproductive function: oestrous cycle:

no effects observed

Description (incidence and severity):

There were no m-bis(2,3-epoxypropoxy)benzene-related effects on estrous cycling at any dose tested. Any differences observed in the number of cycles (regular, irregular or acyclic) and/or mean cycle length were not considered to be related to treatment due to their small magnitude and/or lack of relation to dose.

Reproductive function: sperm measures:

not specified

Reproductive performance:

effects observed, treatment-related

Description (incidence and severity):

There was no m-bis(2,3-epoxypropoxy)benzene-related effect on mating at any dose tested. Specifically, 10 females per group mated. Of these 9, 9, 10, and 8 were pregnant and delivered live born pups at 0, 45, 90, and 180 mg/kg/day, respectively. There was an m-bis(2,3-epoxypropoxy)benzene-related effect on fertility at 180 mg/kg/day. Three (3) of 10 females had a total litter loss, and an additional 2 females failed to deliver by GD 25. During the necropsy, it was confirmed that these females were not pregnant. There were no m-bis(2,3-epoxypropoxy)benzene-related effects on fertility at ≤ 90 mg/kg/day.

Key result

Dose descriptor:

NOAEL

Effect level:

ca. 45 mg/kg bw/day (nominal)

Based on:

test mat.

Sex:

male/female

Basis for effect level:

mortality

body weight and weight gain

food consumption and compound intake

Key result

Critical effects observed:

yes

Lowest effective dose / conc.:

90 mg/kg bw/day (nominal)

System:

gastrointestinal tract

Organ:

stomach

Treatment related:

yes

Gross pathological findings:

not specified

Histopathological findings: non-neoplastic:

not specified

Clinical signs:

not specified

Dermal irritation (if dermal study):

not specified

Mortality / viability:

not specified

Description (incidence and severity):

There were m-bis(2,3-epoxypropoxy)benzene-related decreases on the following indices: post-implantation survival, live birth, and live litter size on PNDs 1, 4, 7 and 13 at 180 mg/kg/day. Beginning on PND 7, the viability index was -33.6% of the concurrent control value, and this reduction persisted until termination (i.e., PND 13). There were no m-bis(2,3-epoxypropoxy)benzene-related effects on the following indices: post implantation survival, live birth, and live litter size on PNDs 1, 4, 7 and 13 at ≤ 90 mg/kg/day. Any differences noted were not considered to be treatment-related due to their to their small magnitude and/or lack of relation to dose.

Body weight and weight changes:

no effects observed

Description (incidence and severity):

There were no m-bis(2,3-epoxypropoxy)benzene-related effects on pup sex or body weight at any dose tested.

Food consumption and compound intake (if feeding study):

not specified

Food efficiency:

not specified

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

not specified

Ophthalmological findings:

not specified

Haematological findings:

not specified

Clinical biochemistry findings:

not specified

Urinalysis findings:

not specified

Sexual maturation:

not specified

Organ weight findings including organ / body weight ratios:

effects observed, treatment-related

Description (incidence and severity):

Male and female (F1) pups at ≥ 45 mg/kg/day had higher mean thyroid gland weights, particularly relative to body weight, compared to control males.

Gross pathological findings:

not specified

Histopathological findings:

not specified

Other effects:

no effects observed

Description (incidence and severity):

There were no m-bis(2,3-epoxypropoxy)benzene-related effects on the length of gestation, total corpora lutea, number of implantations, pre-implantation loss, or average number of pups on PNDs 1, 4, 7, 11 or 13 at any dose tested. Any differences noted were not considered to be treatment-related due to their to their small magnitude and/or lack of relation to dose.

Behaviour (functional findings):

not specified

Developmental immunotoxicity:

not specified

Key result

Dose descriptor:

NOAEL

Generation:

F1

Effect level:

ca. 90 mg/kg bw/day (nominal)

Sex:

male/female

Basis for effect level:

body weight and weight gain

Key result

Critical effects observed:

yes

Lowest effective dose / conc.:

45 mg/kg bw/day (nominal)

System:

endocrine system

Organ:

thyroid gland

Treatment related:

yes

Key result

Reproductive effects observed:

yes

Lowest effective dose / conc.:

90 mg/kg bw/day (nominal)

Treatment related:

yes

Relation to other toxic effects:

reproductive effects occurring together with other toxic effects, but not as a secondary non-specific consequence of other toxic effects

Conclusions:

With all findings considered, the male and female systemic NOAEL was 45 mg/kg/day and the reproductive NOAEL was 90 mg/kg/day.

Effect on fertility: via oral route

Endpoint conclusion:

adverse effect observed

Dose descriptor:

NOAEL

90 mg/kg bw/day

Study duration:

subacute

Species:

rat

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

Effect on developmental toxicity: via oral route

Endpoint conclusion:

no study available

Effect on developmental toxicity: via inhalation route

Endpoint conclusion:

no study available

Effect on developmental toxicity: via dermal route

Endpoint conclusion:

no study available