1,4-divinylbenzene

Endpoint summary

Key value for chemical safety assessment

Effects on fertility

Description of key information

Reproductive toxicity study

The data available for 1,4-Diethenylbenzene and structurally similar read across chemicals was reviewed to determine the reproductive toxicity. The NOAEL for reproductive toxicity was considered to be 200 mg/kg bw as No effects on reproductive parameters were observed .When male and female rats were treated with1,4-Diethenylbenzene orally.Thus, comparing this value with the criteria of CLP 1,4-Diethenylbenzene not likely to classify as reproductive toxicant.

Link to relevant study records

Reference

Endpoint:

screening for reproductive / developmental toxicity

Type of information:

read-across from supporting substance (structural analogue or surrogate)

Adequacy of study:

weight of evidence

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

data from handbook or collection of data

Remarks:

Experimental data of read across substances

Justification for type of information:

Weight of evidence approach based on structurally similar chemicals

Reason / purpose for cross-reference:

read-across source

Reason / purpose for cross-reference:

read-across source

Qualifier:

equivalent or similar to guideline

Guideline:

other: As mentioned below

Principles of method if other than guideline:

WoE report is based on two reproductive toxicity studies on rats 1. Reproductive toxicity study of test material was performed on Charles River COBS CD rats. 2..The reproductive toxicity study of test material was performed on rats

GLP compliance:

not specified

Limit test:

no

Justification for study design:

No data available

Specific details on test material used for the study:

- Name of test material : 1,4-Diethenylbenzene- Molecular formula : C10H10- Molecular weight : 130.189g/mol - Smiles notation : C(c1ccc(cc1)C=C)=C- InChl : 1S/C10H10/c1-3-9-5-7-10(4-2)8-6-9/h3-8H,1-2H2- Substance type : Organic- Physical state : Solid

Species:

rat

Strain:

CD-1

Details on species / strain selection:

No data available

Sex:

male/female

Details on test animals or test system and environmental conditions:

Study 1.Details on test animals and env. conditionsTEST ANIMALS- Age at study initiation: 12 weeks old- Acclimation period: 13 daysStudy 2Details on test animals and env. conditionsTEST ANIMALS- Source:Charles River Japan- Age at study initiation: 5 week old- Weight at study initiation: Males :45 to 65 grams Females :40 to 60 grams- Fasting period before study:- Housing: stainless steel cages were used to keep up to 5 groups per cage. In addition, the mother animals were individually transferred to a plastic cage containing autoclaved bedding (Sunflake, Japan Charles River ) on the 18th day of pregnancy,- Use of restrainers for preventing ingestion (if dermal): yes/no- Diet (e.g. ad libitum): solid feed (CRF-1, Oriental Yeast Co., Ltd. ), ad libitum- Water (e.g. ad libitum): drinking water was freely ingested in tap water. ad libitum- Acclimation period: 7 daysENVIRONMENTAL CONDITIONS- Temperature (°C):20 to 24 ° C.- Humidity (%):40 to 70%,- Air changes (per hr):12 times / hour- Photoperiod (hrs dark / hrs light):light and darkeach for 12 hours (lighting: 6 am to 6 pm)

Route of administration:

oral: gavage

Vehicle:

other: 1.corn oil 2.olive oil

Details on exposure:

Study 1.Details on exposurePREPARATION OF DOSING SOLUTIONS:The appropriate amount of test material was added to 50 ml of the vehicle, Mazola corn oil, and mixed by hand to ensure a homogeneous mixture. The test substance was prepared fresh dailyDIET PREPARATION- Rate of preparation of diet (frequency):No data available- Mixing appropriate amounts with (Type of food )- Storage temperature of food: No data availableVEHICLE- Justification for use and choice of vehicle (if other than water): test material dissolved in , Mazola corn oil- Concentration in vehicle: 0, 25, 100, and 200 mg/kg/day. - Amount of vehicle (if gavage): 5 ml/kg- Lot/batch no. (if required): No data available- Purity: No data availableStudy 2.PREPARATION OF DOSING SOLUTIONS:The test substance was prepared by diluting it with olive oilDIET PREPARATION- Rate of preparation of diet (frequency):No data available- Mixing appropriate amounts with (Type of food )- Storage temperature of food: No data availableVEHICLE- Justification for use and choice of vehicle (if other than water): test material soluble olive oil- Concentration in vehicle: 0, 25, 200, 500, and 600 mg/kg/day - Amount of vehicle (if gavage): 1.0 ml/kg- Lot/batch no. (if required): No data available- Purity: No data available

Details on mating procedure:

Study 1.- M/F ratio per cage:1:1 - Length of cohabitation: - Proof of pregnancy: [vaginal plug / sperm in vaginal smear] referred to as [day 0 / day 1] of pregnancy:The day that evidence of mating was detected was designated day 0 of gestation . - After ... days of unsuccessful pairing replacement of first male by another male with proven fertility. - Further matings after two unsuccessful attempts: [no / yes (explain)] - After successful mating each pregnant female was caged (how): - Any other deviations from standard protocol:

Analytical verification of doses or concentrations:

not specified

Duration of treatment / exposure:

Study 1.20 days ( from day 6 through day 19 )Study 2.-Premating Exposure Period for Female: P, 14 weeks; F1, 17 weeks -Premating Exposure Period for Male: P, 14 weeks; F1, 17 weeks

Frequency of treatment:

daily

Details on study schedule:

No data available

Remarks:

Study 1.0, 25, 100, 200mg/kg bw/dayStudy 2.0, 25, 200, 500, and 600 mg/kg/day

No. of animals per sex per dose:

Study 1.Total:1000 mg/kg bw/day:2525mg/kg bw/day:25100mg/kg bw/day:25200 mg/kg bw/day:25Study 2.Total: 530F0 generation0 mg/kg bw/day:30male and 30 female 25mg/kg bw/day:25male and 25 female200mg/kg bw/day:25male and 25 female500 mg/kg bw/day:30male and 30 female600 mg/kg bw/day:25male and 25 femaleF1 generation 0 mg/kg bw/day:20male and 20 female 25mg/kg bw/day:40male and 40 female200mg/kg bw/day:40male and 40 female500 mg/kg bw/day:40male and 40 female

Control animals:

yes, concurrent vehicle

Details on study design:

No data available

Positive control:

No data available

Parental animals: Observations and examinations:

Study 1.Parental animals observation and examinationsCAGE SIDE OBSERVATIONS: yes DETAILED CLINICAL OBSERVATIONS: Yes Time schedule: They were observed daily for mortality and clinical signs of toxicityBODY WEIGHT: YesTime schedule for examinations: Individual maternal body weights were recorded on gestation days 0, 6, 9, 12, 16, and 20.FOOD CONSUMPTION AND COMPOUND INTAKE (if feeding study): Yes Food consumption was determined weekly. Food consumption for each animal determined and mean daily diet consumption calculated as g food/kg body weight/day: : No data availableCompound intake calculated as time-weighted averages from the consumption and body weight gain data: Yes / No / No data: No data availableWATER CONSUMPTION AND COMPOUND INTAKE (if drinking water study): No data Time schedule for examinations: Study 2.Parental animals observation and examinationsCAGE SIDE OBSERVATIONS: yes DETAILED CLINICAL OBSERVATIONS: Yes Time schedule: daily BODY WEIGHT: YesTime schedule for examinations: weekly FOOD CONSUMPTION AND COMPOUND INTAKE (if feeding study): weeklyFood consumption for each animal determined and mean daily diet consumption calculated as g food/kg body weight/day: No data availableCompound intake calculated as time-weighted averages from the consumption and body weight gain data: Yes / No / No data: No data availableWATER CONSUMPTION AND COMPOUND INTAKE (if drinking water study): No data Time schedule for examinations

Oestrous cyclicity (parental animals):

No data available

Sperm parameters (parental animals):

No data available

Litter observations:

Study 1.All fetuses were individually weighed and examined for external malformations and variations, including the palate and eyes.Study 2.F1 and F2 generation litters were examined as soon as possible after natural delivery. Pup viability and body weights of live pups were recorded at birth (day 1) and when pups were 4, 7, 14, and 21 days old.

Postmortem examinations (parental animals):

Study 1.Postmortem examinations (Parent Animal)SACRIFICE: A Cesarean section was performed on each female on gestation day 20 immediately following sacrifice by carbon dioxide inhalation.GROSS NECROPSY: The thoracic and abdominal cavities and organs of the dams were examined for grossly evident morphological changes and the carcasses discardedHISTOPATHOLOGY / ORGAN WEIGHTSThe tissues indicated in Table [#] were prepared for microscopic examination and weighed, respectively.: macroscopic examination was performed Study 2.SACRIFICE - Male animals: All surviving animals [describe when, e.g. as soon as possible after the last litters in each generation were produced.] - Maternal animals: All surviving animals [describe when, e.g. after the last litter of each generation was weaned.] GROSS NECROPSY: yes - Gross necropsy consisted of [external and internal examinations including the cervical, thoracic, and abdominal viscera.] HISTOPATHOLOGY / ORGAN WEIGHTS: yes The tissues indicated in Table [#] were prepared for microscopic examination and weighed, respectively.

Postmortem examinations (offspring):

Study 1.SACRIFICE - The F1 offspring not selected as parental animals and all F2 offspring were sacrificed at [#?] days of age. - These animals were subjected to postmortem examinations (macroscopic and/or microscopic examination) as follows: GROSS NECROPSY: yes - Gross necropsy consisted of [external and internal examinations .] HISTOPATHOLOGY / ORGAN WEIGTHS: yes Approximately one-half of the fetuses were placed in Bouin's fixative for subsequent visceral examination by razor blade sectioning. The remaining one-half of the fetuses were fixed in alcohol, macerated in potassium hydroxide, and stained with Alizarin Red S for subsequent skeletal examinationStudy 2.At weaning, 5 male and 5 female pups from each treatment group were selected for gross necropsy; after fixation and processing, tissues from the pups from the control and 500 mg/kg/day were examined microscopically.

Statistics:

Study 1.All statistical analyses compared the treatment groups to the control group with the level of significance at p<0.0l and p<0.05. The male to female fetal sex distribution and the number of litters with malformations were compared using the Chi-square test criterion with Yates' correction for 2 x 2 contingency tables and/or Fisher's exact probability tests to judge significance of differences. The number of early resorptions and postimplantation losses were compared by the Mann-Whitney U-test. The mean number of viable fetuses, total implantations, corpora lutea, and mean fetal body weights were compared by ANOVA, Bartlett's test for homogeneity of variances and Dunnett's multiple comparison tables to judge significance of differencesStudy 2.ANOVA, Kruskal-Wallis test were used

Reproductive indices:

No data available

Offspring viability indices:

No data available

Clinical signs:

effects observed, treatment-related

Description (incidence and severity):

Study 1.Hair loss (primarily of the limbs and abdomen) occurred with similar frequency in all treatment and control groups at various intervals throughout the treatment period.Study 2.Physical signs observed in F0 generation rats in the 25, 200, 500, and 600 mg/kg/day dosage groups and attributed to treatment with PMS generally occurred in a dosage-related pattern and included excess salivation and hyperactivity/vocalization. Excess urination during handling, "tiptoe" walk, chromorrhinorrhea/nasal discharge and pilo-erection also occurred in a dosage-related pattern in male rats in these four PMS-treated groups, and in female rats in the 200, 500 and 600 mg/kg/day dosage groups. Rales/dyspnea and urine-stained abdominal fur were considered dose-related in 500 and 600 mg/kg/day dosage group rats

Dermal irritation (if dermal study):

not specified

Mortality:

mortality observed, treatment-related

Description (incidence):

Study 1.Survival was 100% in the control and all treated groups.Study 2.Mortality in the F0 generation for male rats was as follows: 2/54, 0/25, 2/25, 10/30, and 12/25 for control, 25, 200, 500, and 600 mg/kg/day, respectively. Mortality in the F0 generation for female rats was as follows: 2/55, 1/25, 3/27, 7/30, and 14/25 for control, 25, 200, 500, and 600 mg/kg/day, respectively.

Body weight and weight changes:

effects observed, treatment-related

Description (incidence and severity):

Study 1.There were no biologically meaningful differences in mean maternal body weight gain throughout the entire gestation period in any treated group when compared to controlsStudy 2.During the 14 week precohabitation period, dose-related inhibition of average body weight gain was observed in F0 generation male and female rats administered 200, 500, and 600 mg/kg/day, compared with controls. The effect was slightly more severe in male than in female rats and gradually disappeared in rats in the 200 and 500 mg/kg/day groups. Average weekly body weights in rats administered 25 mg/kg/day were comparable to controls during the first 14 weeks. During the postcohabitation period in F0 generation male rats, inhibition of body weight gain was observed in 500 and 600 mg/kg/day groups, compared to controls. Dose-related inhibition of average body weight gain during gestation and lactation occurred in F0 generation female rats administered 600 mg/kg/day, compared to controls.

Food consumption and compound intake (if feeding study):

effects observed, treatment-related

Description (incidence and severity):

Study 2.During the precohabitation period, dose-related inhibition of average weekly food consumption occurred in F0 generation male rats administered 500 and 600 mg/kg/day, compared with controls. male rats administered 200 mg/kg/day, and female rats administered 600 mg/kg/day had significantly higher average weekly food consumption values than controls; Average weekly food consumption of rats in the 25 mg/kg/day group was comparable to vehicle controls. During the first week of the postcohabitation period, F0 generation male rats in 200, 500, and 600 mg/kg/day consumed more food than controls. This effect disappeared after week 1 and may have been associated with the return of the rats from cohabitation to individual housing

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:

not specified

Histopathological findings: non-neoplastic:

not specified

Histopathological findings: neoplastic:

not specified

Other effects:

not specified

Reproductive function: oestrous cycle:

not specified

Reproductive function: sperm measures:

not specified

Reproductive performance:

no effects observed

Description (incidence and severity):

Study 1.There were no biologically meaningful or statistically significant differences in the mean numbers of corpora lutea, total implantations, early resorptions, postimplantation loss, viable fetuses,A slight increase in mean postimplantation loss was observed in the 25 mg/kg/day group when compared to controls. However, no dose-related trend was evident and this response was considered to be due to a random occurrence. Mean postimplantation loss number for 0, 25, 100, and 200 mg/kg/day was 13, 29, 19, and 19, respectively.Non viables and late resorptions were not observed in the control or in any of the treated groupsStudy 2.there was no effect on the mating, fertility, gestation, delivery of pups, or lactation index (survival to weaning of pups alive at day 4).

Dose descriptor:

NOAEL

Effect level:

200 mg/kg bw/day (nominal)

Based on:

test mat.

Sex:

male/female

Basis for effect level:

clinical signs

mortality

body weight and weight gain

food consumption and compound intake

haematology

reproductive function (oestrous cycle)

reproductive performance

Remarks on result:

other: No effects on reproductive performance

Critical effects observed:

not specified

System:

other: not specified

Organ:

not specified

Treatment related:

not specified

Dose response relationship:

not specified

Relevant for humans:

not specified

Clinical signs:

no effects observed

Description (incidence and severity):

Study 2.Physical signs observed in F1 generation rats were similar to those observed in the F0 generation rats. Dose-related signs observed generally occurred in a dose-related pattern. Signs observed in male and female rats which were considered related to administration of 25, 200, and 500 mg/kg/day, compared with controls, included excess salivation, hyperactivity/vocalization, excess urination during handling, "tip-toe" walk, chromorrhinorrhea/nasal discharge and hypersensitivity to touch. Male rats in all dose groups had pilo-erection and ungroomed coat; in female rats this sign was associated only with the 500 mg/kg/day group. Thin appearance in male rats administered 200 and 500 mg/kg/day, and in female rats administered 25, 200, and 500 mg/kg/day was attributed to the test substance. Urine-stained abd ominal fur in 500 mg/kg/day group male rats, and in 200 and 500 mg/kg/day group female rats was also considered dose-related. Decreased motor activity and rales/dyspnea in both male and female rats were considered effects of the 500 mg/kg/day group

Dermal irritation (if dermal study):

not specified

Mortality / viability:

mortality observed, treatment-related

Description (incidence and severity):

Study 1.no effects observed in mean fetal body weight in any of the treated groups when compared to the control groupStudy 2.Mortality in the male F1 generation was as follows: 0/40, 0/40, 1/40, and 19/40 for controls, 25, 200, and 500 mg/kg/day, respectively. Mortality in the female F1 generation was as follows: 1/40, 2/40, 3/40, and 8/40 for controls, 25, 200, and 500 mg/kg/day, respectively

Body weight and weight changes:

effects observed, treatment-related

Description (incidence and severity):

Study 2.dose-related inhibition of average body weight gain was observed in F1 generation male rats in 25, 200, and 500 mg/kg/day, and in F1 generation female rats in 500 mg/kg/day, as compared with controls. F1 generation female rats in 25 mg/kg/day had slightly smaller average body weight gains than controls. This observation was not attributed to the test substance as a dose response was not observed

Food consumption and compound intake (if feeding study):

effects observed, treatment-related

Description (incidence and severity):

Study 2.During the precohabitation period, weeks 1 through 17 of the study, and the postcohabitation period, weeks 21 through 26 of the study, dose-related decrease in average weekly food consumption occurred in 500 mg/kg/day group F1 generation male rats, as compared with controls. In F1 generation female rats in 25 and 200 mg/kg/day, average weekly food consumption was increased, as compared with controls, during the precohabitation and gestation period. The observations disappeared during the lactation period. Average weekly food consumption of 500 mg/kg/day group female rats was similar to controls during the precohabitation, gestation, and lactation periods.

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:

not specified

Gross pathological findings:

no effects observed

Description (incidence and severity):

Study 1.There were no biologically meaningful or statistically significant differences in the number of litters with malformations in any of the treated groups compared to controls. Microphthalmia and thoracoschisis each occurred in one fetus in one litter in the 25 and 200 mg/kg/day groups, respectively. Scoliosis was observed in one litter from both of the 200 mg/kg/day and control groups. The number of litters (and fetuses) with genetic and developmental variations in the treated groups was comparable to controls. Study 2. In F1 weanling pups, there was no morphological evidence of any effect of test material in 25, 200, and 500 mg/kg/day dose group.

Histopathological findings:

no effects observed

Description (incidence and severity):

Study 2.Histopathologic examinations revealed no neoplastic or preneoplastic changes.

Other effects:

no effects observed

Description (incidence and severity):

Study 2.Treatment of F1 generation rats with 25, 200, and 500 mg/kg/day, compared to controls, did not result in alteration of the percentage of rats which mated, the number of days required to mate, the duration of gestation, the fertility index, the gestation index, pup mortality per litter, pup sex ratio or pup average body weight per litter

Behaviour (functional findings):

not specified

Developmental immunotoxicity:

not specified

Dose descriptor:

NOAEL

Generation:

F1

Effect level:

500 mg/kg bw/day (nominal)

Based on:

test mat.

Sex:

male/female

Basis for effect level:

viability

mortality

body weight and weight gain

food consumption and compound intake

gross pathology

histopathology: non-neoplastic

Remarks on result:

other: No developmental toxic effects observed

Critical effects observed:

not specified

System:

other: not specified

Organ:

not specified

Treatment related:

not specified

Dose response relationship:

not specified

Relevant for humans:

not specified

Clinical signs:

not specified

Dermal irritation (if dermal study):

not specified

Mortality / viability:

not specified

Body weight and weight changes:

not specified

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:

not specified

Gross pathological findings:

no effects observed

Description (incidence and severity):

Study 2. In F2 weanling pups, there was no morphological evidence of any effect of test material in 25, 200, and 500 mg/kg/day dose group.

Histopathological findings:

no effects observed

Description (incidence and severity):

Study 2.Histopathologic examinations revealed no neoplastic or preneoplastic changes.

Other effects:

not specified

Behaviour (functional findings):

not specified

Developmental immunotoxicity:

not specified

Dose descriptor:

NOAEL

Generation:

F2

Effect level:

500 mg/kg bw/day (nominal)

Based on:

test mat.

Sex:

not specified

Basis for effect level:

viability

mortality

gross pathology

histopathology: non-neoplastic

Remarks on result:

other: overall no developmental toxic effects observed

Critical effects observed:

not specified

System:

other: not specified

Organ:

not specified

Treatment related:

not specified

Dose response relationship:

not specified

Relevant for humans:

not specified

Reproductive effects observed:

not specified

Treatment related:

not specified

Relation to other toxic effects:

not specified

Dose response relationship:

not specified

Relevant for humans:

not specified

Conclusions:

No Observed Adverse Effect Level (NOAEL) for reproductive and developmental toxicity for male and female was considered to be 200mg/kg/day .When male and female Sprague-Dawley rats were treated with test material orally.

Executive summary:

Data available from different studies were reviewed to determine the reproductive toxicity of 1,4-Diethenylbenzene.The studies are as mentioned below:

Study 1.

The two generation reproductive toxicity study of test material was performed on male and female Sprague-Dawley CD rats. The test material dissolved in olive oil and adminsteried in dose concentration 0,25, 200, 500, and 600 mg/kg/day  orally by gavage (volume of 1.0 ml/kg) to F0 generation . The number of males and females in controls and 500 mg/kg/day were 30 each, and the number of males and females in 25, 200, and 600 mg/kg/day were 25. After 14 weeks of dosing of F0 rats, males and females were placed in cohabitation, one male per each female. The rats continued to receive test material during cohabitation, gestation, delivery, and lactation. At weaning, 5 male and 5 female pups from each treatment group were selected for gross necropsy; after fixation and processing, tissues from the pups from the control and 500 mg/kg/day were examined microscopically.

Forty male and forty female F1 weanling pups from each treatment group were selected for continued treatment with test material (20 males and 20 females were obtained for controls). Treatment groups were administered test material for 17 weeks (25, 200, and 500 mg/kg/day) before cohabitation, during cohabitation, gestation, delivery, and lactation. At weaning, 5 male and 5 female F2 pups from each litter were selected for gross necropsy; after fixation and processing, tissues from the pups from the control and 500 mg/kg/day were examined microscopically.

 

The rats in all treatment groups were observed daily for mortality and clinical signs of toxicity; body weight and food consumption were measured weekly. F1 and F2 generation litters were examined as soon as possible after natural delivery. Pup viability and body weights of live pups were recorded at birth (day 1) and when pups were 4, 7, 14, and 21 days old. Litters were evaluated for maternal and pup behavior during the lactation period, when pup body weights were recorded. 10 adult males and 25 adult females killed by design from each dose were also necropsied, plus animals found dead, and tissues from the control and 500 mg/kg/day were examined microscopically.

 

Mortality in the F0 generation for male rats was as 2/54, 0/25, 2/25, 10/30, and 12/25 for control, 25, 200, 500, and 600 mg/kg/day, respectively. Mortality in the F0 generation for female rats was as follows: 2/55, 1/25, 3/27, 7/30, and 14/25 for control, 25, 200, 500, and 600 mg/kg/day, respectively. Physical signs observed in F0 generation rats in the 25, 200, 500, and 600 mg/kg/day dosage groups and attributed to treatment with test material generally occurred in a dosage-related pattern and included excess salivation and hyperactivity/vocalization. Excess urination during handling, "tiptoe" walk, chromorrhinorrhea/nasal discharge and pilo-erection also occurred in a dosage-related pattern in male rats in these four treated groups, and in female rats in the 200, 500 and 600 mg/kg/day dosage groups. Rales/dyspnea and urine-stained abdominal fur were considered dose-related in 500 and 600 mg/kg/day dosage group rats. 

During the 14 week precohabitation period, dose-related inhibition of average body weight gain was observed in F0 generation male and female rats administered 200, 500, and 600 mg/kg/day, compared with controls. The effect was slightly more severe in male than in female rats and gradually disappeared in rats in the 200 and 500 mg/kg/day groups. Average weekly body weights in rats administered 25 mg/kg/day were comparable to controls during the first 14 weeks.

During the postcohabitation period in F0 generation male rats, inhibition of body weight gain was observed in 500 and 600 mg/kg/day groups, compared to controls. Dose-related inhibition of average body weight gain during gestation and lactation occurred in F0 generation female rats administered 600 mg/kg/day, compared to controls.

During the precohabitation period, dose-related inhibition of average weekly food consumption occurred in F0 generation male rats administered 500 and 600 mg/kg/day, compared with controls. Later in the study, male rats administered 200 mg/kg/day, and female rats administered 600 mg/kg/day had significantly higher average weekly food consumption values than controls. Average weekly food consumption of rats in the 25 mg/kg/day group was comparable to vehicle controls. 

During the first week of the postcohabitation period, F0 generation male rats in 200, 500, and 600 mg/kg/day consumed more food than controls. This effect disappeared after week 1 and may have been associated with the return of the rats from cohabitation to individual housing. 

During gestation in F0 generation female rats, decreased average food consumption was observed in 500 and 600 mg/kg/day, compared with controls. The effect gradually disappeared. During the lactation period, a minimal decrease in average food consumption was observed in 500 and 600 mg/kg/day rats, compared with controls. there was no effect on the mating, fertility, gestation, delivery of pups, or lactation index (survival to weaning of pups alive at day 4).

 

Mortality in the male F1 generation was as 0/40, 0/40, 1/40, and 19/40 for controls, 25, 200, and 500 mg/kg/day, respectively. Mortality in the female F1 generation was as follows: 1/40, 2/40, 3/40, and 8/40 for controls, 25, 200, and 500 mg/kg/day, respectively. Physical signs observed in F1 generation rats were similar to those observed in the F0 generation rats. Dose-related signs observed generally occurred in a dose-related pattern. Signs observed in male and female rats which were considered related to administration of 25, 200, and 500 mg/kg/day, compared with controls, included excess salivation, hyperactivity/vocalization, excess urination during handling, "tip-toe" walk, chromorrhinorrhea/nasal discharge and hypersensitivity to touch. Male rats in all dose groups had pilo-erection and ungroomed coat; in female rats this sign was associated only with the 500 mg/kg/day group. Thin appearance in male rats administered 200 and 500 mg/kg/day, and in female rats administered 25, 200, and 500 mg/kg/day was attributed to the test substance. Urine-stained abdominal fur in 500 mg/kg/day group male rats, and in 200 and 500 mg/kg/day group female rats was also considered dose-related. Decreased motor activity and rales/dyspnea in both male and female rats were considered effects of the 500 mg/kg/day group. 

During the 17-week precohabitation period, dose-related inhibition of average body weight gain was observed in F1 generation male rats in 25, 200, and 500 mg/kg/day, and in F1 generation female rats in 500 mg/kg/day, as compared with controls. F1 generation female rats in 25 mg/kg/day had slightly smaller average body weight gains than controls. This observation was not attributed to the test substance as a dose response was not observed. Administration of 200 mg/kg/day, compared with controls. Dose-related inhibition of average body weight gain persisted during the postcohabitation period, for F1 generation male rats in the 25, 200, and 500 mg/kg/day groups, compared with controls.
For F1 generation female rats, dose-related lower average body weights persisted for the 500 mg/kg/day group, compared with controls, during the gestation, lactation, and postweaning periods.

During the precohabitation period, weeks 1 through 17 of the study, and the postcohabitation period, weeks 21 through 26 of the study, dose-related decrease in average weekly food consumption occurred in 500 mg/kg/day group F1 generation male rats, as compared with controls. In F1 generation female rats in 25 and 200 mg/kg/day, average weekly food consumption was increased, as compared with controls, during the precohabitation and gestation period. The observations disappeared during the lactation period. Average weekly food consumption of 500 mg/kg/day group female rats was similar to controls during the precohabitation, gestation, and lactation periods.

Administration of 500 mg/kg/day to F1 generation male and female rats, compared to controls, resulted in a small increase in the incidence of stillborn pups and in a slight increase in pup mortality. Differences were not significant at p<0.05. 

Treatment of F1 generation rats with 25, 200, and 500 mg/kg/day, compared to controls, did not result in alteration of the percentage of rats which mated, the number of days required to mate, the duration of gestation, the fertility index, the gestation index, pup mortality per litter, pup sex ratio or pup average body weight per litter.

 In F1 and F2 weanling pups, there was no morphological evidence of any effect of test material Histopathologic examinations revealed no neoplastic or preneoplastic changes Specifically, morphologic examinations of F0 adults (gross only) and F1 adults and F1 and F2 pups (gross and microscopic) revealed no evidence of any treatment effect on the organs of reproduction. At a dose of 600 mg/kg/day, there were adverse effects on both the parents (increased mortality, reduced weight gain, excitability) and on the pups (slightly smaller litter size, slightly more mortality during the first 4 days after birth, and slightly less weight gain). at 500 mg/kg/day dose group similar adverse effects (mortality, reduced weight gain, excitability) were seen in the parents, but less pronounced effects on pups (slightly smaller litter size and slightly more mortality during the first 4 days after birth in the first generation only). at At 200 mg/kg/day dose group , there were no effects on the success of reproduction or health of offspring, and only a slight effect on the behavior of the parents (excitability).

There was no effect of treatment with test material on the viability of pups from dams dosed at 25 or at 200 mg/kg/day. In addition, there was no effect on the mating, fertility, gestation, delivery of pups, or lactation index (survival to weaning of pups alive at day 4). The growth rate of pups from dams dosed at 25, 200, or 500 mg/kg/day was not different from the pups from the control dams. Pups from dams dosed at 600 mg/kg/day showed a 10% reduction in body weight, both at birth and at weaning, as compared to the controls.The effects observed in the offspring of the rats dosed at 500 or 600 mg/kg/day probably resulted from maternal toxicity, not from effects of test material directly on the reproductive process. HenceNo Observed Adverse Effect Level (NOAEL) for reproductive and developmental toxicity for male and female was considered to be 200mg/kg/day .When male and femaleSprague-Dawleyrats were treated with test material orally.

Study 2.

The reproductive and developmental toxicity study of test material was performed inPregnant Charles River COBS CD rats. Dosage levels of 25, 100, and 200 mg/kg/day were administered orally by gavage as a single daily dose on days 6 through 19 of gestation at a constant volume of 5 ml/kg.The control group received the vehicle only, Mazola corn oil, on a comparable regimen.One female and one male rat of the same strain and source were placed together for mating. The occurrence of copulation was determined by daily inspection for a copulatory plug. The day that evidenice of mating was detected was designated day 0 of gestation and the female was returned to an individual cage.Dams were observed daily for mortality and clinical signs of toxicity .Individual maternal body weights were recorded on gestation days 0, 6, 9, 12, 16, and 20. A Cesarean section was performed on each female on gestation day 20 immediately following sacrifice by carbon dioxide inhalation. The uterus was excised and weighed prior to removal of the fetuses. The number and location of viable and nonviable fetuses, early and late resorptions, total implantations and corpora lutea were recorded. The thoracic and abdominal cavities and organs of the dams were examined for grossly evident morphological changes and the carcasses discarded. Uteri from females that appeared nongravid were opened and placed in 10% ammonium sulfide solution for confirmation of pregnancy status. All fetuses were individually weighed and examined for external malformations and variations, including the palate and eyes. Each fetus was externally sexed and individually numbered and tagged for identification. Approximately one-half of the fetuses were placed in Bouin's fixative for subsequent visceral examination by razor blade sectioning. The remaining one-half of the fetuses were fixed in alcohol, macerated in potassium hydroxide, and stained with
Alizarin Red S for subsequent skeletal examination.

 There were no biologically meaningful differences in the appearance or behavior of the rats in the 25, 100, or 200 mg/kg/day groups when compared to controls. Hair loss (primarily of the limbs and abdomen) occurred with similar frequency in all treatment and control groups at various intervals throughout the treatment period. Survival was 100% in the control and all treated groups. There were no biologically meaningful differences in mean maternal body weight gain throughout the entire gestation period in any treated group when compared to controls. There were no biologically meaningful or statistically significant differences in the mean numbers of corpora lutea, total implantations, early resorptions, postimplantation loss, viable fetuses, the fetal sex distribution or mean fetal body weight in any of the treated groups when compared to the control group. Non viables and late resorptions were not observed in the control or in any of the treated groups. A slight increase in mean postimplantation loss was observed in the 25 mg/kg/day group when compared to controls. However, no dose-related trend was evident and this response was considered to be due to a random occurrence. Mean postimplantation loss number for 0, 25, 100, and 200 mg/kg/day was 13, 29, 19, and 19, respectively.
 There were no biologically meaningful or statistically significant differences in the number of litters with malformations in any of the treated groups compared to controls. Microphthalmia and thoracoschisis each occurred in one fetus in one litter in the 25 and 200 mg/kg/day groups, respectively. Scoliosis was observed in one litter from both of the 200 mg/kg/day and control groups. The number of litters (and fetuses) with genetic and developmental variations in the treated groups was comparable to controls.  Hence No Observed Adverse Effect Level (NOAEL) for reproductive and developmental was considered to be 200mg/kg/day.When femaleCD 1rats were treated with test material orally.

  Based on the data available from different studies, 1,4-Diethenylbenzene did not showedreproductive toxicityat dose concentration200mg/kg bw/day.Hence the test chemical is not likely to classify as a reproductive toxicant as per the criteria mentioned in CLP regulation.

Effect on fertility: via oral route

Endpoint conclusion:

no adverse effect observed

Dose descriptor:

NOAEL

200 mg/kg bw/day

Study duration:

subchronic

Species:

rat

Quality of whole database:

Data is Klimicsh 2 and from authoritative database

Effect on fertility: via inhalation route

Endpoint conclusion:

no study available

Effect on fertility: via dermal route

Endpoint conclusion:

no study available

Additional information

Reproductive toxicity study

Data available from different studies were reviewed to determine the reproductive toxicity of 1,4-Diethenylbenzene.The studies are as mentioned below:

Study 1.

The two generation reproductive toxicity study of test material was performed on male and female Sprague-Dawley CD rats. The test material dissolved in olive oil and adminsteried in dose concentration 0,25, 200, 500, and 600 mg/kg/day  orally by gavage (volume of 1.0 ml/kg) to F0 generation . The number of males and females in controls and 500 mg/kg/day were 30 each, and the number of males and females in 25, 200, and 600 mg/kg/day were 25. After 14 weeks of dosing of F0 rats, males and females were placed in cohabitation, one male per each female. The rats continued to receive test material during cohabitation, gestation, delivery, and lactation. At weaning, 5 male and 5 female pups from each treatment group were selected for gross necropsy; after fixation and processing, tissues from the pups from the control and 500 mg/kg/day were examined microscopically.Forty male and forty female F1 weanling pups from each treatment group were selected for continued treatment with test material (20 males and 20 females were obtained for controls). Treatment groups were administered test material for 17 weeks (25, 200, and 500 mg/kg/day) before cohabitation, during cohabitation, gestation, delivery, and lactation. At weaning, 5 male and 5 female F2 pups from each litter were selected for gross necropsy; after fixation and processing, tissues from the pups from the control and 500 mg/kg/day were examined microscopically.

 

The rats in all treatment groups were observed daily for mortality and clinical signs of toxicity; body weight and food consumption were measured weekly. F1 and F2 generation litters were examined as soon as possible after natural delivery. Pup viability and body weights of live pups were recorded at birth (day 1) and when pups were 4, 7, 14, and 21 days old. Litters were evaluated for maternal and pup behavior during the lactation period, when pup body weights were recorded. 10 adult males and 25 adult females killed by design from each dose were also necropsied, plus animals found dead, and tissues from the control and 500 mg/kg/day were examined microscopically.

 

Mortality in the F0 generation for male rats was as 2/54, 0/25, 2/25, 10/30, and 12/25 for control, 25, 200, 500, and 600 mg/kg/day, respectively. Mortality in the F0 generation for female rats was as follows: 2/55, 1/25, 3/27, 7/30, and 14/25 for control, 25, 200, 500, and 600 mg/kg/day, respectively. Physical signs observed in F0 generation rats in the 25, 200, 500, and 600 mg/kg/day dosage groups and attributed to treatment with test material generally occurred in a dosage-related pattern and included excess salivation and hyperactivity/vocalization. Excess urination during handling, "tiptoe" walk, chromorrhinorrhea/nasal discharge and pilo-erection also occurred in a dosage-related pattern in male rats in these four treated groups, and in female rats in the 200, 500 and 600 mg/kg/day dosage groups. Rales/dyspnea and urine-stained abdominal fur were considered dose-related in 500 and 600 mg/kg/day dosage group rats. 

During the 14 week precohabitation period, dose-related inhibition of average body weight gain was observed in F0 generation male and female rats administered 200, 500, and 600 mg/kg/day, compared with controls. The effect was slightly more severe in male than in female rats and gradually disappeared in rats in the 200 and 500 mg/kg/day groups. Average weekly body weights in rats administered 25 mg/kg/day were comparable to controls during the first 14 weeks.

During the postcohabitation period in F0 generation male rats, inhibition of body weight gain was observed in 500 and 600 mg/kg/day groups, compared to controls. Dose-related inhibition of average body weight gain during gestation and lactation occurred in F0 generation female rats administered 600 mg/kg/day, compared to controls.

During the precohabitation period, dose-related inhibition of average weekly food consumption occurred in F0 generation male rats administered 500 and 600 mg/kg/day, compared with controls. Later in the study, male rats administered 200 mg/kg/day, and female rats administered 600 mg/kg/day had significantly higher average weekly food consumption values than controls. Average weekly food consumption of rats in the 25 mg/kg/day group was comparable to vehicle controls. 

During the first week of the postcohabitation period, F0 generation male rats in 200, 500, and 600 mg/kg/day consumed more food than controls. This effect disappeared after week 1 and may have been associated with the return of the rats from cohabitation to individual housing. 

During gestation in F0 generation female rats, decreased average food consumption was observed in 500 and 600 mg/kg/day, compared with controls. The effect gradually disappeared. During the lactation period, a minimal decrease in average food consumption was observed in 500 and 600 mg/kg/day rats, compared with controls. there was no effect on the mating, fertility, gestation, delivery of pups, or lactation index (survival to weaning of pups alive at day 4).

 

Mortality in the male F1 generation was as 0/40, 0/40, 1/40, and 19/40 for controls, 25, 200, and 500 mg/kg/day, respectively. Mortality in the female F1 generation was as follows: 1/40, 2/40, 3/40, and 8/40 for controls, 25, 200, and 500 mg/kg/day, respectively. Physical signs observed in F1 generation rats were similar to those observed in the F0 generation rats. Dose-related signs observed generally occurred in a dose-related pattern. Signs observed in male and female rats which were considered related to administration of 25, 200, and 500 mg/kg/day, compared with controls, included excess salivation, hyperactivity/vocalization, excess urination during handling, "tip-toe" walk, chromorrhinorrhea/nasal discharge and hypersensitivity to touch. Male rats in all dose groups had pilo-erection and ungroomed coat; in female rats this sign was associated only with the 500 mg/kg/day group. Thin appearance in male rats administered 200 and 500 mg/kg/day, and in female rats administered 25, 200, and 500 mg/kg/day was attributed to the test substance. Urine-stained abdominal fur in 500 mg/kg/day group male rats, and in 200 and 500 mg/kg/day group female rats was also considered dose-related. Decreased motor activity and rales/dyspnea in both male and female rats were considered effects of the 500 mg/kg/day group. 

During the 17-week precohabitation period, dose-related inhibition of average body weight gain was observed in F1 generation male rats in 25, 200, and 500 mg/kg/day, and in F1 generation female rats in 500 mg/kg/day, as compared with controls. F1 generation female rats in 25 mg/kg/day had slightly smaller average body weight gains than controls. This observation was not attributed to the test substance as a dose response was not observed. Administration of 200 mg/kg/day, compared with controls. Dose-related inhibition of average body weight gain persisted during the postcohabitation period, for F1 generation male rats in the 25, 200, and 500 mg/kg/day groups, compared with controls.
For F1 generation female rats, dose-related lower average body weights persisted for the 500 mg/kg/day group, compared with controls, during the gestation, lactation, and postweaning periods.

During the precohabitation period, weeks 1 through 17 of the study, and the postcohabitation period, weeks 21 through 26 of the study, dose-related decrease in average weekly food consumption occurred in 500 mg/kg/day group F1 generation male rats, as compared with controls. In F1 generation female rats in 25 and 200 mg/kg/day, average weekly food consumption was increased, as compared with controls, during the precohabitation and gestation period. The observations disappeared during the lactation period. Average weekly food consumption of 500 mg/kg/day group female rats was similar to controls during the precohabitation, gestation, and lactation periods.

Administration of 500 mg/kg/day to F1 generation male and female rats, compared to controls, resulted in a small increase in the incidence of stillborn pups and in a slight increase in pup mortality. Differences were not significant at p<0.05. 

Treatment of F1 generation rats with 25, 200, and 500 mg/kg/day, compared to controls, did not result in alteration of the percentage of rats which mated, the number of days required to mate, the duration of gestation, the fertility index, the gestation index, pup mortality per litter, pup sex ratio or pup average body weight per litter.

 In F1 and F2 weanling pups, there was no morphological evidence of any effect of test material Histopathologic examinations revealed no neoplastic or preneoplastic changes Specifically, morphologic examinations of F0 adults (gross only) and F1 adults and F1 and F2 pups (gross and microscopic) revealed no evidence of any treatment effect on the organs of reproduction. At a dose of 600 mg/kg/day, there were adverse effects on both the parents (increased mortality, reduced weight gain, excitability) and on the pups (slightly smaller litter size, slightly more mortality during the first 4 days after birth, and slightly less weight gain). at 500 mg/kg/day dose group similar adverse effects (mortality, reduced weight gain, excitability) were seen in the parents, but less pronounced effects on pups (slightly smaller litter size and slightly more mortality during the first 4 days after birth in the first generation only). at At 200 mg/kg/day dose group , there were no effects on the success of reproduction or health of offspring, and only a slight effect on the behavior of the parents (excitability).

There was no effect of treatment with test material on the viability of pups from dams dosed at 25 or at 200 mg/kg/day. In addition, there was no effect on the mating, fertility, gestation, delivery of pups, or lactation index (survival to weaning of pups alive at day 4). The growth rate of pups from dams dosed at 25, 200, or 500 mg/kg/day was not different from the pups from the control dams. Pups from dams dosed at 600 mg/kg/day showed a 10% reduction in body weight, both at birth and at weaning, as compared to the controls.The effects observed in the offspring of the rats dosed at 500 or 600 mg/kg/day probably resulted from maternal toxicity, not from effects of test material directly on the reproductive process. Hence No Observed Adverse Effect Level (NOAEL) for reproductive and developmental toxicity for male and female rats was considered to be 200mg/kg/day .When male and femaleSprague-Dawley rats were treated with test material orally.

Study 2

The reproductive and developmental toxicity study of test material was performed in Pregnant Charles River COBS CD rats. Dosage levels of 25, 100, and 200 mg/kg/day were administered orally by gavage as a single daily dose on days 6 through 19 of gestation at a constant volume of 5 ml/kg.The control group received the vehicle only, Mazola corn oil, on a comparable regimen.One female and one male rat of the same strain and source were placed together for mating. The occurrence of copulation was determined by daily inspection for a copulatory plug. The day that evidenice of mating was detected was designated day 0 of gestation and the female was returned to an individual cage.Dams were observed daily for mortality and clinical signs of toxicity .Individual maternal body weights were recorded on gestation days 0, 6, 9, 12, 16, and 20. A Cesarean section was performed on each female on gestation day 20 immediately following sacrifice by carbon dioxide inhalation. The uterus was excised and weighed prior to removal of the fetuses. The number and location of viable and nonviable fetuses, early and late resorptions, total implantations and corpora lutea were recorded. The thoracic and abdominal cavities and organs of the dams were examined for grossly evident morphological changes and the carcasses discarded. Uteri from females that appeared nongravid were opened and placed in 10% ammonium sulfide solution for confirmation of pregnancy status. All fetuses were individually weighed and examined for external malformations and variations, including the palate and eyes. Each fetus was externally sexed and individually numbered and tagged for identification. Approximately one-half of the fetuses were placed in Bouin's fixative for subsequent visceral examination by razor blade sectioning. The remaining one-half of the fetuses were fixed in alcohol, macerated in potassium hydroxide, and stained with Alizarin Red S for subsequent skeletal examination.

There were no biologically meaningful differences in the appearance or behavior of the rats in the 25, 100, or 200 mg/kg/day groups when compared to controls. Hair loss (primarily of the limbs and abdomen) occurred with similar frequency in all treatment and control groups at various intervals throughout the treatment period. Survival was 100% in the control and all treated groups. There were no biologically meaningful differences in mean maternal body weight gain throughout the entire gestation period in any treated group when compared to controls. There were no biologically meaningful or statistically significant differences in the mean numbers of corpora lutea, total implantations, early resorptions, postimplantation loss, viable fetuses, the fetal sex distribution or mean fetal body weight in any of the treated groups when compared to the control group. Non viables and late resorptions were not observed in the control or in any of the treated groups. A slight increase in mean postimplantation loss was observed in the 25 mg/kg/day group when compared to controls. However, no dose-related trend was evident and this response was considered to be due to a random occurrence. Mean postimplantation loss number for 0, 25, 100, and 200 mg/kg/day was 13, 29, 19, and 19, respectively.
 There were no biologically meaningful or statistically significant differences in the number of litters with malformations in any of the treated groups compared to controls. Microphthalmia and thoracoschisis each occurred in one fetus in one litter in the 25 and 200 mg/kg/day groups, respectively. Scoliosis was observed in one litter from both of the 200 mg/kg/day and control groups. The number of litters (and fetuses) with genetic and developmental variations in the treated groups was comparable to controls.  Hence No Observed Adverse Effect Level (NOAEL) for reproductive and developmental was considered to be 200mg/kg/day.When female CD 1rats were treated with test material orally.

Based on the data available from different studies, 1,4-Diethenylbenzene did not showed reproductive toxicity at dose concentration 200mg/kg bw/day.Hence the test chemical is not likely to classify as a reproductive toxicant as per the criteria mentioned in CLP regulation.

Effects on developmental toxicity

Description of key information

Developmental toxicity study

The data available for 1,4-Diethenylbenzene and structurally similar read across chemicals was reviewed to determine thedevelopmental toxicity .The NOAEL for reproductive toxicity was considered to be above 30-200mg/kg bw/day  as no effects on developmental parameters  .When male and female rats or mice were treated with1,4-Diethenylbenzene .Thus, comparing this value with the criteria of CLP regulation 1,4-Diethenylbenzene  not likely to classify as reproductive and developmental toxicant.

Link to relevant study records

Reference

Endpoint:

developmental toxicity

Type of information:

read-across from supporting substance (structural analogue or surrogate)

Adequacy of study:

weight of evidence

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

data from handbook or collection of data

Remarks:

Experimental data of read across substances

Justification for type of information:

Weight of evidence approach based on structurally similar chemicals

Reason / purpose for cross-reference:

read-across source

Reason / purpose for cross-reference:

read-across source

Qualifier:

equivalent or similar to guideline

Guideline:

other: As mentioned below

Principles of method if other than guideline:

WoE report is based on two developmental toxicity studies on rats 1. Developmental toxicity study of test material was performed on Charles River COBS CD rats. 2.Repeated oral administration toxicity / reproductive developmental toxicity combined study of test material was performed on rats.

GLP compliance:

not specified

Limit test:

no

Specific details on test material used for the study:

Name of test material : 1,4-Diethenylbenzene- Molecular formula : C10H10- Molecular weight : 130.189g/mol - Smiles notation : C(c1ccc(cc1)C=C)=C- InChl : 1S/C10H10/c1-3-9-5-7-10(4-2)8-6-9/h3-8H,1-2H2- Substance type : Organic- Physical state : Solid

Species:

rat

Strain:

Sprague-Dawley

Remarks:

[Crj: CD (SD) IGS, (SPF)]

Details on test animals or test system and environmental conditions:

Study 1Details on test animals and env. conditionsTEST ANIMALS- Source:- Age at study initiation: 12 weeks old- Acclimation period: 13 daysStudy 2.Details on test animals and env. conditionsTEST ANIMALS- Source: Charles River Japan- Age at study initiation: 8-week-old- Weight at study initiation: Males :315 to 352 g Females :211 to 239 g - Fasting period before study:- Housing: stainless steel cages were used to keep up to 5 groups per cage. In addition, the mother animals were individually transferred to a plastic cage containing autoclaved bedding (Sunflake, Japan Charles River ) on the 18th day of pregnancy,- Use of restrainers for preventing ingestion (if dermal): yes/no- Diet (e.g. ad libitum): solid feed (CRF- 1, Oriental Yeast Co., Ltd. ), ad libitum- Water (e.g. ad libitum): drinking water was freely ingested in tap water. ad libitum- Acclimation period: 7 daysENVIRONMENTAL CONDITIONS- Temperature (°C):20 to 24 ° C.- Humidity (%):40 to 70%,- Air changes (per hr):12 times / hour- Photoperiod (hrs dark / hrs light):light and darkeach for 12 hours (lighting: 6 am to 6 pm)

Route of administration:

oral: gavage

Vehicle:

corn oil

Details on exposure:

Study 1Details on exposurePREPARATION OF DOSING SOLUTIONS:The appropriate amount of test material was added to 50 ml of the vehicle, Mazola corn oil, and mixed by hand to ensure a homogeneous mixture. The test substance was prepared fresh dailyDIET PREPARATION- Rate of preparation of diet (frequency):No data available- Mixing appropriate amounts with (Type of food )- Storage temperature of food: No data availableVEHICLE- Justification for use and choice of vehicle (if other than water): test material dissolved in , Mazola corn oil- Concentration in vehicle: 0, 25, 100, and 200 mg/kg/day. - Amount of vehicle (if gavage): 5 ml/kg- Lot/batch no. (if required): No data available- Purity: No data availableStudy 2.Details on exposurePREPARATION OF DOSING SOLUTIONS:The test substance was prepared by diluting it with corn oil.DIET PREPARATION- Rate of preparation of diet (frequency):No data available- Mixing appropriate amounts with (Type of food )- Storage temperature of food: No data availableVEHICLE- Justification for use and choice of vehicle (if other than water): test material soluble corn oil- Concentration in vehicle: 0, 30, 100, 300 and1000 mg / kg- Amount of vehicle (if gavage): 5 ml/kg- Lot/batch no. (if required): No data available- Purity: No data available

Analytical verification of doses or concentrations:

not specified

Details on mating procedure:

Study 1.- Impregnation procedure: [artificial insemination / purchased timed pregnant / cohoused] - If cohoused: - M/F ratio per cage: 1::1 - Length of cohabitation: - After ... days of unsuccessful pairing replacement of first male by another male with proven fertility. - Further matings after two unsuccessful attempts: [no / yes (explain)] - Verification of same strain and source of both sexes: [yes / no (explain)] - Proof of pregnancy: [vaginal plug / sperm in vaginal smear] referred to as [day 0 / day 1] of pregnancy:The day that evidence of mating was detected was designated day 0 of gestation - Any other deviations from standard protocol:Study 2.- Impregnation procedure: [artificial insemination / purchased timed pregnant / cohoused] - If cohoused: - M/F ratio per cage: 1:1 - Length of cohabitation: 14 days - After ... days of unsuccessful pairing replacement of first male by another male with proven fertility. - Further matings after two unsuccessful attempts: [no / yes (explain)] - Verification of same strain and source of both sexes: [yes / no (explain)] - Proof of pregnancy: [vaginal plug / sperm in vaginal smear] referred to as [day 0 / day 1] of pregnancy:a female who confirmed sperm or vaginal plug in vaginal plaque was a mating animal and the day was counted as the 0th day of pregnancy - Any other deviations from standard protocol:

Duration of treatment / exposure:

Study 1.20 days ( from day 6 through day 19 )Study 2.50 days

Frequency of treatment:

Daily

Duration of test:

Study 1.20 days Study 2.50 days

Remarks:

Study 1.0, 25, 100, 200mg/kg bw/dayStudy 2.0, 30, 100, 300, 1000 mg/kg bw/day

No. of animals per sex per dose:

Study 1.Total:1000 mg/kg bw/day:2525mg/kg bw/day:25100mg/kg bw/day:25200 mg/kg bw/day:25Study 2.Total:1200 mg/kg bw/day: 12 male and 12 females 30mg/kg bw/day:12 male and 12 females100mg/kg bw/day:12 male and 12 females300 mg/kg bw/day:12 male and 12 females1000 mg/kg bw/day:12 male and 12 females

Control animals:

yes, concurrent vehicle

Details on study design:

No data available

Maternal examinations:

Study 1Parental animals observation and examinationsCAGE SIDE OBSERVATIONS: yes DETAILED CLINICAL OBSERVATIONS: Yes Time schedule: They were observed daily for mortality and clinical signs of toxicityBODY WEIGHT: YesTime schedule for examinations: Individual maternal body weights were recorded on gestation days 0, 6, 9, 12, 16, and 20.FOOD CONSUMPTION AND COMPOUND INTAKE (if feeding study): Yes Food consumption was determined weekly. Food consumption for each animal determined and mean daily diet consumption calculated as g food/kg body weight/day: : No data availableCompound intake calculated as time-weighted averages from the consumption and body weight gain data: Yes / No / No data: No data availableWATER CONSUMPTION AND COMPOUND INTAKE (if drinking water study): No data Time schedule for examinations: Study 2.Parental animals observation and examinationsCAGE SIDE OBSERVATIONS: yes DETAILED CLINICAL OBSERVATIONS: Yes Time schedule: They were observed daily for mortality and clinical signs of toxicityBODY WEIGHT: YesTime schedule for examinations: male: Body weight was measured twice a week. Female: Body weights were measured 14 days before the mating and twice weekly during the mating period, on 0, 7, 14 and 21 gestation during gestation, on 0 and 4 nursing during the feeding period, respectivelyFOOD CONSUMPTION AND COMPOUND INTAKE (if feeding study): Yes Feeding amount was measured twice weekly 14 days before the start of the mating and after the end of the mating period. Also, during pregnancy, gestation was measured on 2, 9, 16 and 21 gestation, and during nursing during 4 days of nursing.Food consumption for each animal determined and mean daily diet consumption calculated as g food/kg body weight/day: YCompound intake calculated as time-weighted averages from the consumption and body weight gain data: Yes / No / No data: No data available

Ovaries and uterine content:

Study 1& 2.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:

Fetal examinations:

Study 1&2.- External examinations: Yes: all per litter - Soft tissue examinations:No data - Skeletal examinations: No data - Head examinations: No data

Statistics:

Study 1.All statistical analyses compared the treatment groups to the control group with the level of significance at p<0.0l and p<0.05. The male to female fetal sex distribution and the number of litters with malformations were compared using the Chi-square test criterion with Yates' correction for 2 x 2 contingency tables and/or Fisher's exact probability tests to judge significance of differences. The number of early resorptions and postimplantation losses were compared by the Mann-Whitney U-test. The mean number of viable fetuses, total implantations, corpora lutea, and mean fetal body weights were compared by ANOVA, Bartlett's test for homogeneity of variances and Dunnett's multiple comparison tables to judge significance of differences. Study 2.For the significant difference test, a homogeneous distribution test by the Bartlett method, and if it is equipartised, a variance analysis is performed by the one-way method, and if it is significant, it is done by the Dunnett method. On the other hand, in the case where it was not recognized as equal variance, we performed analysis by one-way method using rank order (Kruskal-Wallis test), and if significant, use Dunnett type test method using ranking.

Indices:

No data available

Historical control data:

No data available

Clinical signs:

effects observed, treatment-related

Description (incidence and severity):

Study 1.Hair loss (primarily of the limbs and abdomen) occurred with similar frequency in all treatment and control groups at various intervals throughout the treatment period.Study 2.No abnormalities were observed in any animals throughout the observation period in the control group. Salivation was observed after administration in groups above 30 mg / kg. In the 1000mg / kg group, skin temperature warming and depilation were observed in one case and contamination of the coat in 1 to 8 cases. Salivation was observed in each group up to about 30 minutes after administration, and no change was observed in salivation duration even when administration was continued. Damage to the incisors was observed in the 100 mg / kg group, but only one case was found and it was judged as a contingent case.

Dermal irritation (if dermal study):

not specified

Mortality:

no mortality observed

Description (incidence):

Study 1.Survival was 100% in the control and all treated groups.Study 2.For male: Death and moribund cases were not observed in either group.For female animals, one case of death and one case of moribund were observed in the 1000 mg / kg group

Body weight and weight changes:

effects observed, treatment-related

Description (incidence and severity):

Study 1.There were no biologically meaningful differences in mean maternal body weight gain throughout the entire gestation period in any treated group when compared to controls.Study 2.The body weights of the 30 and 100 mg / kg group were almost the same as those of the control group, and no significant difference was observed on any measurement day. In the 300 mg / kg group, the body weight was significantly lower on the 8th day of administration than in the control group. In the 1000 mg / kg group, there was a significant lower value of body weight on 4 to 50 days of administration than in the control group.

Food consumption and compound intake (if feeding study):

effects observed, treatment-related

Description (incidence and severity):

Study 2.The food consumption of the 30 mg / kg group was almost the same as that of the control group, and no significant difference was observed on any measurement day. In the 100 mg / kg group, a significant increase in food intake was observed on Days 34 and 38 compared to the control group. In the 300 mg / kg group, a significant increase in food intake was observed on the 34 th to 48 th day of administration compared with the control group. In the 1000 mg / kg group, a significant low value of food intake was found on the 3rd day of administration compared to the control group, and a significant high value of food intake was observed on the 13th to 48th days of administration.

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:

not specified

Description (incidence and severity):

Study 2.In the 30 mg / kg group, there was no significant difference in absolute weight and relative weight of any organ compared to the control group. In the 100 mg / kg group, a significant elevation of the relative weight of the liver was observed compared to the control group. In the 300 mg / kg group, a significant high value of the absolute weight of the kidney as well as a significant high value of the relative weight of the liver and kidney was observed compared to the control group. In the 1000 mg / kg group, the relative weights of the liver and kidney were significantly higher than the control group, and there was no significant difference, but the absolute weight tendency of the kidney was high. Besides, in the 1000 mg / kg group, significant lower values of the absolute weights of the heart, spleen and epididymis as compared with the control group, and significant higher values of relative weights of the brain and testis were observed The change in absolute weight and relative weight was not found to have a certain tendency, so it was judged that it was not based on administration.

Gross pathological findings:

no effects observed

Description (incidence and severity):

Study 2.There was no abnormality in any of the control group, 30, 100 and 300 mg / kg group. In the 1000 mg / kg group, dark red spots of glandular gastric mucosa were found in one case but judged as a contingent case.At necropsy of surviving cases, no abnormality was observed in the control group and 300 mg / kg group. At 30 mg / kg group, thymus atrophy was found in one case. In the 100 mg / kg group, ulcers of the forestomachial mucosa were found in one case. In the 1000 mg / kg group, whitening of the adrenal glands on both sides occurred in 1 case and atrophy of the thymus was seen in 7 cases. Thymus atrophy was observed at necropsy of deaths in the 1000 mg / kg group. At necropsy of the moribund case in the 1000 mg / kg group, atrophy of thymus and dark red spots of glandular gastric mucosa were observed.

Neuropathological findings:

not specified

Histopathological findings: non-neoplastic:

no effects observed

Description (incidence and severity):

Study 2.Necrotic necrosis of the liver, seminiferous tube atrophy of the testes, and sperm granulomas of the epididymis were observed, but they were judged as accidental changes because they were seen at the same degree in the control group or in a small number

Histopathological findings: neoplastic:

not specified

Other effects:

not specified

Number of abortions:

not specified

Pre- and post-implantation loss:

effects observed, treatment-related

Description (incidence and severity):

Study 1.A slight increase in mean postimplantation loss was observed in the 25 mg/kg/day group when compared to controls. However, no dose-related trend was evident and this response was considered to be due to a random occurrence. Mean postimplantation loss number for 0, 25, 100, and 200 mg/kg/day was 13, 29, 19, and 19, respectively.Study 2.In the 1000 mg / kg group, the number of corpus luteum and the number of implantation traces were significantly lower than in the control group

Total litter losses by resorption:

not specified

Early or late resorptions:

not specified

Dead fetuses:

no effects observed

Changes in pregnancy duration:

no effects observed

Description (incidence and severity):

Migrated Data from removed field(s)
Field "Effects on pregnancy duration" (Path: ENDPOINT_STUDY_RECORD.DevelopmentalToxicityTeratogenicity.ResultsAndDiscussion.ResultsMaternalAnimals.MaternalDevelopmentalToxicity.EffectsOnPregnancyDuration): no effects observed
Field "Description (incidence and severity)" (Path: ENDPOINT_STUDY_RECORD.DevelopmentalToxicityTeratogenicity.ResultsAndDiscussion.ResultsMaternalAnimals.MaternalDevelopmentalToxicity.DescriptionIncidenceAndSeverityEffectsOnPregnancyDuration): Study 2.There was no significant difference between the gestation period and the control group in each administration group

Changes in number of pregnant:

no effects observed

Other effects:

not specified

Dose descriptor:

NOAEL

Effect level:

> 200 - <= 300 mg/kg bw/day (nominal)

Based on:

test mat.

Basis for effect level:

body weight and weight gain

clinical signs

dead fetuses

early or late resorptions

effects on pregnancy duration

food consumption and compound intake

gross pathology

histopathology: non-neoplastic

mortality

number of abortions

pre and post implantation loss

Remarks on result:

other: no effects on reproductive performance

Abnormalities:

not specified

Localisation:

not specified

Fetal body weight changes:

no effects observed

Description (incidence and severity):

Study 2.In the 30 mg / kg group, the body weight was significantly higher in males and females on day 0 of nursing than in the control group, but not in a dose dependent manner. In the 100, 300 and 1000 mg / kg group, the body weight was significantly lower in males and females on day 0 of nursing compared to the control group. In the 1000 mg / kg group, there was no significant difference compared with the control group, but the body weight tended to be low in males and females on 4th day of nursing.
Migrated Data from removed field(s)
Field "Fetal/pup body weight changes" (Path: ENDPOINT_STUDY_RECORD.DevelopmentalToxicityTeratogenicity.ResultsAndDiscussion.ResultsFetuses.FetalPupBodyWeightChanges): no effects observed
Field "Description (incidence and severity)" (Path: ENDPOINT_STUDY_RECORD.DevelopmentalToxicityTeratogenicity.ResultsAndDiscussion.ResultsFetuses.DescriptionIncidenceAndSeverityFetalPupBodyWeightChanges): Study 1.no effects observed in mean fetal body weight in any of the treated groups when compared to the control group

Reduction in number of live offspring:

no effects observed

Changes in sex ratio:

no effects observed

Description (incidence and severity):

Study 1.no effects observed in the fetal sex distribution in any of the treated groups when compared to the control group

Changes in litter size and weights:

not specified

Changes in postnatal survival:

not specified

Description (incidence and severity):

Study 2.In the 30 mg / kg group, tail defects and tail were observed, and in the 100 mg / kg group tail necrosis was observed, but both were findings observed in external table observation or general condition observation, and it was judged as a contingent case . Besides, no abnormality was found in any group.

External malformations:

no effects observed

Description (incidence and severity):

Study 1.There were no biologically meaningful or statistically significant differences in the number of litters with malformations in any of the treated groups compared to controls. Microphthalmia and thoracoschisis each occurred in one fetus in one litter in the 25 and 200 mg/kg/day groups, respectively. Scoliosis was observed in one litter from both of the 200 mg/kg/day and control groups. The number of litters (and fetuses) with genetic and developmental variations in the treated groups was comparable to controls.

Skeletal malformations:

not specified

Visceral malformations:

not specified

Other effects:

not specified

Dose descriptor:

NOAEL

Effect level:

> 30 - <= 200 mg/kg bw/day (nominal)

Based on:

test mat.

Sex:

not specified

Basis for effect level:

fetal/pup body weight changes

changes in litter size and weights

external malformations

Remarks on result:

other: No developmental toxic effects observed

Abnormalities:

not specified

Localisation:

other: not specified

Developmental effects observed:

not specified

Treatment related:

not specified

Relation to maternal toxicity:

not specified

Dose response relationship:

not specified

Relevant for humans:

not specified

Table : Number of estrous cases and reproductive performance of male and female rats in combined repeat dose and reproductive/ developmental toxicity screening test of test material by oral administration

Dose (mg/kg)	0	30	100	300	1000
Number of females Number of estrous cases before mating Mean ± S.D.	12         3.3 ± 0.7	12         3.3 ± 0.9	12         3.4 ± 0.5	12         3.7 ± 0.5	12         2.8 ± 1.1
Number of pairs   Number of pairs with successful copulation   Copulation index (%)^a)   Number of conceiving days Mean ± S.D.   Number of pregnant females   Fertility index (%)^b) Number of pregnant females with live pups	12     11         91.7           3.1± 1.0   11       100.0     11	12     12         100.0           2.3 ± 1.1   12       100.0     11	12     12         100.0           2.7 ± 3.4   12       100.0     12	12     12         100.0           2.5 ± 1.0   12       100.0     12	12     12         100.0           3.5 ± 2.0   11       91.7     9

 

a) : (Number of pairs with successful copulation/number of pairs) X 100

b) : (Number of pregnant females/number of pairs with successful copulation) X 100

Table : Observation of pups in combined repeat dose and reproductive/developmental toxicity screening test of test material by oral administration.

Dose (mg/kg)	0	30	100	300	1000
No. Of Dams	11	12	12	12	9
Length of gestation( days) Mean ± S.D. per dam	22.09 ± 0.30	22.42 ± 0.67	22.08 ± 0.29	22.08 ± 0.29	22.22 ± 0.44
Number of corpora lutea   Mean ± S.D. per dam	17.5 ± 1.3	17.5 ± 1.9	17.5 ± 1.5	16.1 ± 2.5	15.0 ± 2.1^*
Number of implantation scars   Mean ± S.D. per dam	16.3 ± 1.2	16.5 ± 1.3	16.1 ± 1.3	14.7 ± 2.5	13.7 ± 0.2^**
Implantation index   Mean ± S.D. per dam^a)   Gestation index( %)^b)	92.7 ± 4.6   100.0	94.7 ± 6.9   91.7	91.9 ± 5.6   100.0	91.2 ± 10.1   100.0	91.3 ± 8.7   100.0
Number of live pups born   Mean ± S.D. per dam	14.8 ± 1.0	13.6 ± 4.4	14.7 ± 1.5	14.4 ± 2.6	9.1 ± 3.0^**
Sex ratio at birth   Mean ± S.D. per dam^c)	1.06 ± 0.64	1.19 ± 0.66 (11)	1.25 ± 0.48	0.89 ± 0.45	1.20 ± 0.78
Birth index   Mean ± S.D. per dam^d)	91.2 ± 5.6	83.9 ± 27.2	91.4 ± 9.1	98.3 ± 4.4^**	69.3 ± 27.3
Number of pups born   Mean ± S.D. per dam	15.1 ± 0.8	15.3 ± 1.6	15.0 ± 1.8	14.4 ± 2.6	11.7 ± 3.1^**
Delivery index   Mean ± S.D. per dam^e)	92.8 ± 5.0	92.9 ± 6.3	93.4 ± 9.3	98.3 ± 4.4	86.2 ± 21.7
Live birth index   Mean ± S.D. per dam^f)	98.1 ± 3.3	90.1 ± 28.6	98.0 ± 3.8	100.0 ± 0.0	80.7 ± 23.6^*
Number of live pups on day 4 of lactation   Mean ± S.D. per dam	14.5 ± 0.7	14.2 ± 2.0 (11)	14.6 ± 1.4	14.3 ± 2.5	2.2 ± 4.4^**
Viability index   Mean ± S.D. per dam^g)	97.6 ± 4.2	95.5 ± 9.2 (11)	99.5 ± 1.7	98.9 ±2.5	20.2 ± 40.4^**
Number of external anomalies   Mean ± S.D. per dam^h)	0.0 ± 0.0	0.6 ± 2.1 (11)	0.5 ± 1.7	0.0 ± 0.0	0.0 ± 0.0
Anury   Mean ± S.D. per dam	0.0 ± 0.0	0.6 ± 2.1 (11)	0.0 ± 0.0	0.0 ± 0.0	0.0 ± 0.0
Necrosis of tail   Mean ± S.D. per dam	0.0 ± 0.0	0.0 ± 0.0 (11)	0.5 ± 1.7	0.0 ± 0.0	0.0 ± 0.0
Body weight of pups( g)   Mean ± S.D. per dam
Male   Day 0   Day 4	6.46 ± 0.56   10.17 ± 0.89	6.66 ± 0.44^**(11)   10.43 ± 1.00 (11)	6.31 ± 0.46^** 9.76 ± 1.26	6.28 ± 0.53^** 9.86 ± 1.03	4.89 ± 0.75^** 7.90      (2)
Female   Day 0     Day 4	6.18 ± 0.47     9.66 ± 0.74	6.30 ± 0.42^**(11)     9.94 ± 1.12 (11)	5.96 ± 0.47^** 9.43 ± 1.25	5.84 ± 0.52^** 9.18 ± 1.15	4.50 ± 0.76^** 7.05     (2)

 

a) : (Number of implantation mars/number of corpora lutea) X100

b) : (Number of dams with live pups/number of pregnant dams) x100

c) :Number of male pups/number of female pups.

d) : (Number of live pups born/number of implantation scars) X 100

e) : (Number of pups born/number of implantation scars) X 100.

 f) : (Number of live pups born/number of pups born) x100

g) : (Number of live pups on day 4/number of live pups born) X 100

h) : (Number of pups with external anomalies/number of live pup s) X 100

Figures in parentheses indicate number of dams.

Significantly different from control( *: p<0.05, **: p<0.01)

Conclusions:

No Observed Adverse Effect Level (NOAEL) for developmental toxicity was considered to be above 30-200mg/kg/day. When male and female Sprague-Dawley rats were treated with test material orally.

Executive summary:

Data available from different studies were reviewed to determine the developmental toxicityof  1,4-Diethenylbenzene .The studies are as mentioned below:

Study 1.

The developmental toxicity study of test material was performed inPregnant Charles River COBS CD rats. Dosage levels of 25, 100, and 200 mg/kg/day were administered orally by gavage as a single daily dose on days 6 through 19 of gestation at a constant volume of 5 ml/kg.The control group received the vehicle only, Mazola corn oil, on a comparable regimen.One female and one male rat of the same strain and source were placed together for mating. The occurrence of copulation was determined by daily inspection for a copulatory plug. The day that evidenice of mating was detected was designated day 0 of gestation and the female was returned to an individual cage.Dams were observed daily for mortality and clinical signs of toxicity .Individual maternal body weights were recorded on gestation days 0, 6, 9, 12, 16, and 20. A Cesarean section was performed on each female on gestation day 20 immediately following sacrifice by carbon dioxide inhalation. The uterus was excised and weighed prior to removal of the fetuses. The number and location of viable and nonviable fetuses, early and late resorptions, total implantations and corpora lutea were recorded. The thoracic and abdominal cavities and organs of the dams were examined for grossly evident morphological changes and the carcasses discarded. Uteri from females that appeared nongravid were opened and placed in 10% ammonium sulfide solution for confirmation of pregnancy status. All fetuses were individually weighed and examined for external malformations and variations, including the palate and eyes. Each fetus was externally sexed and individually numbered and tagged for identification. Approximately one-half of the fetuses were placed in Bouin's fixative for subsequent visceral examination by razor blade sectioning. The remaining one-half of the fetuses were fixed in alcohol, macerated in potassium hydroxide, and stained with Alizarin Red S for subsequent skeletal examination.

There were no biologically meaningful differences in the appearance or behavior of the rats in the 25, 100, or 200 mg/kg/day groups when compared to controls. Hair loss (primarily of the limbs and abdomen) occurred with similar frequency in all treatment and control groups at various intervals throughout the treatment period. Survival was 100% in the control and all treated groups. There were no biologically meaningful differences in mean maternal body weight gain throughout the entire gestation period in any treated group when compared to controls. There were no biologically meaningful or statistically significant differences in the mean numbers of corpora lutea, total implantations, early resorptions, postimplantation loss, viable fetuses, the fetal sex distribution or mean fetal body weight in any of the treated groups when compared to the control group. Non viables and late resorptions were not observed in the control or in any of the treated groups. A slight increase in mean postimplantation loss was observed in the 25 mg/kg/day group when compared to controls. However, no dose-related trend was evident and this response was considered to be due to a random occurrence. Mean postimplantation loss number for 0, 25, 100, and 200 mg/kg/day was 13, 29, 19, and 19, respectively.
 There were no biologically meaningful or statistically significant differences in the number of litters with malformations in any of the treated groups compared to controls. Microphthalmia and thoracoschisis each occurred in one fetus in one litter in the 25 and 200 mg/kg/day groups, respectively. Scoliosis was observed in one litter from both of the 200 mg/kg/day and control groups. The number of litters (and fetuses) with genetic and developmental variations in the treated groups was comparable to controls.  Hence No Observed Adverse Effect Level (NOAEL) for developmental was considered to be 200mg/kg/day.When femaleCD 1rats were treated with test materialorally.

Study 2.

Thecombined repeat dose and reproductive/ developmental toxicity screening test was performed on male and femaleSprague-Dawley rats [Crj: CD (SD) IGS, (SPF)]. The test materialsolublein corn oil in dose concentration 0, 30,100,300,1000mg/kg and administered orally by gavage.The dose was determined according to the results of a preliminary test (administration stage: 0, 125, 250, 500 and 1000 mg / kg, 5 groups in each group) by oral administration for 2 weeks using the male rat previously performed. Male and female rats administered for 14 days were mated together in a 1: 1 combination within the same group. The mating period was limited to 14 days and consecutive living crosses were made until mating was confirmed. Mating was confirmed approximately every morning at a fixed time and a female who confirmed sperm or vaginal plug in vaginal plaque was a mating animal and the day was counted as the 0th day of pregnancy. The general condition and the presence or absence of death was observed twice a day before and after administration. Body weight was measured twice a week. Feeding amount was measured twice weekly 14 days before the start of the mating and after the end of the mating period. The sex cycle was observed once a day from the administration start date to the mating confirmation date. In addition, when the estrus period was observed over 2 consecutive days, it was counted as 1 time. Females who did not deliver until 25th day of pregnancy were sacrificed by exsanguination from the abdominal aorta under ether anesthesia and autopsied, and the success or failure of the pregnancy was confirmed by the presence or absence of implantation. The mother animal was observed daily until the 4th day of nursing and the autopsy was done after leaving the abdominal aorta from the abdominal aorta under ether anesthesia on the day when all newborns died or on the 4^thday of nursing. At birth the number of total births and sex, the number of stillborn babies, the number of neonates and the presence or absence of outer table abnormalities were observed. Body weight was measured on day 0 of nursing (birthday) and 4th day.

 

Death and moribund cases were not observed in either group in male while in female Deaths and moribund cases were not observed in the control group, 30, 100 and 300 mg / kg group.

In the 1000 mg / kg group, one patient died on the 17th day of pregnancy and one died during labor on the 23^rdpregnancy. In death cases, salivation, depilation, epidermal decline, loss of locomotor activity, bleeding from the vaginal opening was observed. In the moribund case, salivation, warming of the epidermis, and decline of locomotor activity were observed. In the general condition observation of surviving cases, no abnormalities were observed in any animals throughout the observation period in the control group and 30 mg / kg group. Salivation was observed after administration in the group of 100 mg / kg or more. In the 1000 mg / kg group, hair loss was seen in one case, and the stain on the hair was observed in 1 or 2 cases. Body weights of the 30, 100 and 300 mg / kg group were almost the same as those of the control group, and no significant difference was observed on any measurement day. In the 1000 mg / kg group, there was a significant lower value of body weight. Before the mating, food intake in the 30, 100 and 300 mg / kg group was almost similar to that of the control group, and no significant difference was observed on any measurement day. In the 1000 mg / kg group, a significant lowering of food intake was observed on the 3rd day of administration, on the 21st day of pregnancy, on the 4^thday of nursing compared with the control group. At necropsy of the moribund case in the 1000 mg / kg group, atrophy of thymus and dark red spots of glandular gastric mucosa were observed. In the 1000 mg / kg group, significant lower values of the absolute weights of the brain, pituitary and heart as compared with the control group, and significant higher values of the relative weights of the brain and ovary were observed, but these changes were absolute Since a certain tendency was not observed in weight and relative weight, it was judged that it was not based on administration. There was no significant difference in the number of estrous cycles in the administration period (14 days) before mating with the control group in each administration group. There was no significant difference between the gestation period and the control group in each administration group. In addition, no abnormality was found in the delivery status in any of the animals.

In the 30, 100 and 300 mg / kg groups, there were no significant differences in the corpus luteum count, implantation trace number and implantation rate compared to the control group. In the 1000 mg / kg group, the number of corpus luteum and the number of implantation traces were significantly lower than in the control group. In the control group, 100, 300 and 1000 mg / kg group, the birth rate was 100%. In the 30 mg / kg group, the baby rate was 91.7% because no newborn was obtained in one case, but it was judged that it was not based on administration. In the control group, 30, 100 and 300 mg / kg group, no abnormalities were observed in the nursing condition. In the 1000 mg / kg group, 3 maternal animals showed mammary gland development defects and poor nesting defects from day 0 of nursing or day 1 of nursing, and 7 cases of newborn mothers who died in all cases were observed. In the 30, 100 and 300 mg / kg groups, there was no significant difference in the number of neonates, birth rate and sex ratio on day 0 of nursing compared to the control group. In the 30 and 100 mg / kg group, there was no significant difference in the output of children compared with the control group. In the 300 mg / kg group, the child's output rate was significantly higher than that of the control group, but not the dose-dependent change. In the 1000 mg / kg group, there was a significant lower number of neonates and fertility rates on day 0 of nursing compared to the control group, and a low value trend of the output rate of children with no significant difference. In the 30, 100 and 300 mg / kg groups, there was no significant difference in the number of surviving children on 4th day of nursing, the survival rate on 4th day of feeding and the sex ratio compared to the control group. In the 1000 mg / kg group, the number of surviving children on 4th day of nursing and the survival rate on 4th day of nursing were significantly lower than in the control group. In the general condition of the newborn, tail trauma, tail loss, and epidermal decline were seen in each case in the 30 mg / kg group, but both cases were judged to be contingent cases. In the 1000 mg / kg group, a case of trauma of the tail was found in 4 cases in the 4th abdomen (3 mice were mother animals in which mammary gland development failure and nesting defect were observed). In the 30 mg / kg group, the body weight was significantly higher in males and females on day 0 of nursing than in the control group, but not in a dose dependent manner. In the 100, 300 and 1000 mg / kg group, the body weight was significantly lower in males and females on day 0 of nursing compared to the control group. In the 1000 mg / kg group, there was no significant difference compared with the control group, but the body weight tended to be low in males and females on 4th day of nursing. In the 30 mg / kg group, tail defects and tail were observed, and in the 100 mg / kg group tail necrosis was observed, but both were findings observed in external table observation or general condition observation, and it was judged as a contingent case. Besides, no abnormality was found in any group. Hence No Observed Adverse Effect Level (NOAEL) for developmental toxicity was considered to be 30 mg/kg as body weight was found to be lower by administration of 100 mg / kg,When male and femaleSprague-Dawleyrats were treated with test materialorally.

Based on the data available from different studies,1,4-Diethenylbenzene did not showeddevelopmental toxicityat dose concentrationabove 30-200mg/kg bw/day.Hence the test chemical is not likely to classify as a reproductive and developmental toxicant as per the criteria mentioned in CLP regulation.

.

Effect on developmental toxicity: via oral route

Endpoint conclusion:

no adverse effect observed

Dose descriptor:

NOAEL

200 mg/kg bw/day

Study duration:

subchronic

Species:

rat

Quality of whole database:

Data is Klimicsh 2 and from authoritative database

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 study

Data available from different studies were reviewed to determine the developmental toxicityof  1,4-Diethenylbenzene .The studies are as mentioned below:

Study 1.

The developmental toxicity study of test material was performed in Pregnant Charles River COBS CD rats. Dosage levels of 25, 100, and 200 mg/kg/day were administered orally by gavage as a single daily dose on days 6 through 19 of gestation at a constant volume of 5 ml/kg.The control group received the vehicle only, Mazola corn oil, on a comparable regimen.One female and one male rat of the same strain and source were placed together for mating. The occurrence of copulation was determined by daily inspection for a copulatory plug. The day that evidenice of mating was detected was designated day 0 of gestation and the female was returned to an individual cage.Dams were observed daily for mortality and clinical signs of toxicity .Individual maternal body weights were recorded on gestation days 0, 6, 9, 12, 16, and 20. A Cesarean section was performed on each female on gestation day 20 immediately following sacrifice by carbon dioxide inhalation. The uterus was excised and weighed prior to removal of the fetuses. The number and location of viable and nonviable fetuses, early and late resorptions, total implantations and corpora lutea were recorded. The thoracic and abdominal cavities and organs of the dams were examined for grossly evident morphological changes and the carcasses discarded. Uteri from females that appeared nongravid were opened and placed in 10% ammonium sulfide solution for confirmation of pregnancy status. All fetuses were individually weighed and examined for external malformations and variations, including the palate and eyes. Each fetus was externally sexed and individually numbered and tagged for identification. Approximately one-half of the fetuses were placed in Bouin's fixative for subsequent visceral examination by razor blade sectioning. The remaining one-half of the fetuses were fixed in alcohol, macerated in potassium hydroxide, and stained with Alizarin Red S for subsequent skeletal examination.

There were no biologically meaningful differences in the appearance or behavior of the rats in the 25, 100, or 200 mg/kg/day groups when compared to controls. Hair loss (primarily of the limbs and abdomen) occurred with similar frequency in all treatment and control groups at various intervals throughout the treatment period. Survival was 100% in the control and all treated groups. There were no biologically meaningful differences in mean maternal body weight gain throughout the entire gestation period in any treated group when compared to controls. There were no biologically meaningful or statistically significant differences in the mean numbers of corpora lutea, total implantations, early resorptions, postimplantation loss, viable fetuses, the fetal sex distribution or mean fetal body weight in any of the treated groups when compared to the control group. Non viables and late resorptions were not observed in the control or in any of the treated groups. A slight increase in mean postimplantation loss was observed in the 25 mg/kg/day group when compared to controls. However, no dose-related trend was evident and this response was considered to be due to a random occurrence. Mean postimplantation loss number for 0, 25, 100, and 200 mg/kg/day was 13, 29, 19, and 19, respectively.
 There were no biologically meaningful or statistically significant differences in the number of litters with malformations in any of the treated groups compared to controls. Microphthalmia and thoracoschisis each occurred in one fetus in one litter in the 25 and 200 mg/kg/day groups, respectively. Scoliosis was observed in one litter from both of the 200 mg/kg/day and control groups. The number of litters (and fetuses) with genetic and developmental variations in the treated groups was comparable to controls.  Hence No Observed Adverse Effect Level (NOAEL) for developmental was considered to be 200mg/kg/day.When femaleCD 1rats were treated with test materialorally.

Study 2.

Thecombined repeat dose and reproductive/ developmental toxicity screening test was performed on male and femaleSprague-Dawley rats [Crj: CD (SD) IGS, (SPF)]. The test materialsolublein corn oil in dose concentration 0, 30,100,300,1000mg/kg and administered orally by gavage.The dose was determined according to the results of a preliminary test (administration stage: 0, 125, 250, 500 and 1000 mg / kg, 5 groups in each group) by oral administration for 2 weeks using the male rat previously performed. Male and female rats administered for 14 days were mated together in a 1: 1 combination within the same group. The mating period was limited to 14 days and consecutive living crosses were made until mating was confirmed. Mating was confirmed approximately every morning at a fixed time and a female who confirmed sperm or vaginal plug in vaginal plaque was a mating animal and the day was counted as the 0th day of pregnancy. The general condition and the presence or absence of death was observed twice a day before and after administration. Body weight was measured twice a week. Feeding amount was measured twice weekly 14 days before the start of the mating and after the end of the mating period. The sex cycle was observed once a day from the administration start date to the mating confirmation date. In addition, when the estrus period was observed over 2 consecutive days, it was counted as 1 time. Females who did not deliver until 25th day of pregnancy were sacrificed by exsanguination from the abdominal aorta under ether anesthesia and autopsied, and the success or failure of the pregnancy was confirmed by the presence or absence of implantation. The mother animal was observed daily until the 4th day of nursing and the autopsy was done after leaving the abdominal aorta from the abdominal aorta under ether anesthesia on the day when all newborns died or on the 4^thday of nursing. At birth the number of total births and sex, the number of stillborn babies, the number of neonates and the presence or absence of outer table abnormalities were observed. Body weight was measured on day 0 of nursing (birthday) and 4th day.

 

Death and moribund cases were not observed in either group in male while in female Deaths and moribund cases were not observed in the control group, 30, 100 and 300 mg / kg group.

In the 1000 mg / kg group, one patient died on the 17th day of pregnancy and one died during labor on the 23^rdpregnancy. In death cases, salivation, depilation, epidermal decline, loss of locomotor activity, bleeding from the vaginal opening was observed. In the moribund case, salivation, warming of the epidermis, and decline of locomotor activity were observed. In the general condition observation of surviving cases, no abnormalities were observed in any animals throughout the observation period in the control group and 30 mg / kg group. Salivation was observed after administration in the group of 100 mg / kg or more. In the 1000 mg / kg group, hair loss was seen in one case, and the stain on the hair was observed in 1 or 2 cases. Body weights of the 30, 100 and 300 mg / kg group were almost the same as those of the control group, and no significant difference was observed on any measurement day. In the 1000 mg / kg group, there was a significant lower value of body weight. Before the mating, food intake in the 30, 100 and 300 mg / kg group was almost similar to that of the control group, and no significant difference was observed on any measurement day. In the 1000 mg / kg group, a significant lowering of food intake was observed on the 3rd day of administration, on the 21st day of pregnancy, on the 4^thday of nursing compared with the control group. At necropsy of the moribund case in the 1000 mg / kg group, atrophy of thymus and dark red spots of glandular gastric mucosa were observed. In the 1000 mg / kg group, significant lower values of the absolute weights of the brain, pituitary and heart as compared with the control group, and significant higher values of the relative weights of the brain and ovary were observed, but these changes were absolute Since a certain tendency was not observed in weight and relative weight, it was judged that it was not based on administration. There was no significant difference in the number of estrous cycles in the administration period (14 days) before mating with the control group in each administration group. There was no significant difference between the gestation period and the control group in each administration group. In addition, no abnormality was found in the delivery status in any of the animals.

In the 30, 100 and 300 mg / kg groups, there were no significant differences in the corpus luteum count, implantation trace number and implantation rate compared to the control group. In the 1000 mg / kg group, the number of corpus luteum and the number of implantation traces were significantly lower than in the control group. In the control group, 100, 300 and 1000 mg / kg group, the birth rate was 100%. In the 30 mg / kg group, the baby rate was 91.7% because no newborn was obtained in one case, but it was judged that it was not based on administration. In the control group, 30, 100 and 300 mg / kg group, no abnormalities were observed in the nursing condition. In the 1000 mg / kg group, 3 maternal animals showed mammary gland development defects and poor nesting defects from day 0 of nursing or day 1 of nursing, and 7 cases of newborn mothers who died in all cases were observed. In the 30, 100 and 300 mg / kg groups, there was no significant difference in the number of neonates, birth rate and sex ratio on day 0 of nursing compared to the control group. In the 30 and 100 mg / kg group, there was no significant difference in the output of children compared with the control group. In the 300 mg / kg group, the child's output rate was significantly higher than that of the control group, but not the dose-dependent change. In the 1000 mg / kg group, there was a significant lower number of neonates and fertility rates on day 0 of nursing compared to the control group, and a low value trend of the output rate of children with no significant difference. In the 30, 100 and 300 mg / kg groups, there was no significant difference in the number of surviving children on 4th day of nursing, the survival rate on 4th day of feeding and the sex ratio compared to the control group. In the 1000 mg / kg group, the number of surviving children on 4th day of nursing and the survival rate on 4th day of nursing were significantly lower than in the control group. In the general condition of the newborn, tail trauma, tail loss, and epidermal decline were seen in each case in the 30 mg / kg group, but both cases were judged to be contingent cases. In the 1000 mg / kg group, a case of trauma of the tail was found in 4 cases in the 4th abdomen (3 mice were mother animals in which mammary gland development failure and nesting defect were observed). In the 30 mg / kg group, the body weight was significantly higher in males and females on day 0 of nursing than in the control group, but not in a dose dependent manner. In the 100, 300 and 1000 mg / kg group, the body weight was significantly lower in males and females on day 0 of nursing compared to the control group. In the 1000 mg / kg group, there was no significant difference compared with the control group, but the body weight tended to be low in males and females on 4th day of nursing. In the 30 mg / kg group, tail defects and tail were observed, and in the 100 mg / kg group tail necrosis was observed, but both were findings observed in external table observation or general condition observation, and it was judged as a contingent case. Besides, no abnormality was found in any group. Hence No Observed Adverse Effect Level (NOAEL) for developmental toxicity was considered to be 30 mg/kg as body weight was found to be lower by administration of 100 mg / kg,When male and femaleSprague-Dawleyrats were treated with test materialorally.

Based on the data available from different studies,1,4-Diethenylbenzene did not showed developmental toxicity at dose concentration above 30-200mg/kg bw/day.Hence the test chemical is not likely to classify as a reproductive and developmental toxicant as per the criteria mentioned in CLP regulation.

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Justification for classification or non-classification

Thus, comparing this value with the criteria of CLP 1,4-Diethenylbenzene not likely to classify as reproductive and developmental toxicant.