Divinylbenzene

Repeated dose toxicity: oral

Administrative data

Endpoint:

sub-chronic toxicity: oral

Type of information:

experimental study

Adequacy of study:

key study

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

guideline study

Justification for type of information:

Data from J- check

Data source

Reference

Reference Type:

review article or handbook

Title:

Repeated oral administration toxicity / reproductive developmental toxicity combined study of test material

Author:

J- check

Year:

2003

Bibliographic source:

Ministry of Health and Welfare, Japan, 2003

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

OECD Guideline 422 (Combined Repeated Dose Toxicity Study with the Reproduction / Developmental Toxicity Screening Test)

Principles of method if other than guideline:

Repeated oral administration toxicity / reproductive developmental toxicity combined study of test material was performed on rats

GLP compliance:

not specified

Limit test:

yes

Test material

Test material information

Constituent 1

Reference substance name:

Divinylbenzene

EC Number:

215-325-5

EC Name:

Divinylbenzene

Cas Number:

1321-74-0

Molecular formula:

C10H10

IUPAC Name:

1,2-di(ethenyl)benzene

Details on test material:

- Name of test material: Divinylbenzene- IUPAC name: 1,2-di(ethenyl)benzene - Molecular formula: C10H10- Molecular weight: 131.1969 g/mol- Substance type: Organic- Physical state: No data - Purity: No data- Impurities (identity and concentrations): No data

Test animals

Species:

rat

Strain:

Sprague-Dawley

Sex:

male/female

Details on test animals or test system and environmental conditions:

TEST 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 CharlesRiver ) 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)

Administration / exposure

Route of administration:

oral: gavage

Vehicle:

corn oil

Details on oral exposure:

PREPARATION 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

Duration of treatment / exposure:

Males, day 50Females, day 4 of lactation

Frequency of treatment:

daily

Doses / concentrations

Doses / concentrations 1

Dose / conc.:

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

Doses / concentrations 2

Dose / conc.:

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

Doses / concentrations 3

Dose / conc.:

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

Doses / concentrations 4

Dose / conc.:

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

Doses / concentrations 5

Dose / conc.:

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

No. of animals per sex per dose:

Total:1200 mg/kg bw/day: 12 male and 12 females30mg/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:

- Dose selection rationale: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.

Positive control:

not specified

Examinations

Observations and examinations performed and frequency:

Parental animals observation and examinationsCAGE SIDE OBSERVATIONS: yesDETAILED CLINICAL OBSERVATIONS: YesTime schedule: They were observed daily for mortality and clinical signs of toxicity.BODY 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, res pectivelyFOOD 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: Yes Compound 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 dataTime schedule for examinations:OPHTHALMOSCOPIC EXAMINATION: Yes / No / Not specified- Time schedule for examinations:- Dose groups that were examined:HAEMATOLOGY: Yes - Time schedule for collection of blood:At the end of the administration period. - Anaesthetic used for blood collection: Yes, sodium pentobarbital- Animals fasted: Not specified- How many animals:All - Parameters checked in table [No.?] were examined. red blood cell count (RBC), the hemoglobin amount, the hematocrit value, the platelet count and the white blood cell count (WBC), mean red blood cell volume (MCV), mean red blood cell hemoglobin amount (MCH) and mean red blood cell hemoglobin concentration (MCHC), Prothrombin time (PT), activated partial thromboplastin time (APTT) and fibrinogen concentration were examined. CLINICAL CHEMISTRY: Yes - Time schedule for collection of blood:At the end of the administration period. - Animals fasted: Not specified- How many animals: All - Parameters checked in table [No.?] were examined. GOT and GPT, ALP, γ-GTP, total protein, total bilirubin, urea nitrogen (BUN), glucose, total cholesterol, triglyceride, Ca, inorganic phosphorus, Na and K, Cl, albumin, A / G ratio were examined. OTHER:Organ weight:The brain (cerebrum, cerebellum, medulla oblongata), pituitary gland, thyroid, thymus, heart, liver, spleen, kidney, adrenal glands, testicles and epididymis were weighed.

Sacrifice and pathology:

GROSS PATHOLOGY: Yes, gross pathological examined were performed on all the organs. HISTOPATHOLOGY: Yes, Paraffin-embedded specimens were prepared for the excised organs and tissues according to a conventional method. In the control group and the 1000 mg / kg group of heart, lung, trachea, liver, pancreas, stomach, duodenum, jejunum, ileum, cecum, colon, rectum, thymus, spleen, lymph node (mandibular mesentery), kidney, adrenal gland , Bladder, testis, epididymis, seminal vesicle, prostate, pituitary gland, thyroid, parathyroid gland (only for testable animals), brain (cerebrum / cerebellum / medulla oblongata), spinal cord, sciatic nerve and bone marrow ), HE - stained tissue specimens were prepared and examined histopathologically.

Statistics:

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, weperformed analysis by one-way method using rank order (Kruskal-Wallis test), and if significant, use Dunnett type test method using ranking.

Results and discussion

Results of examinations

Clinical signs:

no effects observed

Description (incidence and severity):

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

Mortality:

mortality observed, non-treatment-related

Description (incidence):

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, non-treatment-related

Description (incidence and severity):

The body weights of the 30 and 100 mg / kg group were almost the same as those of the control group.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):

The food consumption of the 30 mg / kg group was almost the same as that of the control group.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 34th 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:

effects observed, non-treatment-related

Description (incidence and severity):

In the 30 mg / kg group, a significant high value of erythrocyte count was seen compared with the control group, but it was judged that it was not a dose dependent change and not based on administration. In the 100 and 300 mg/ kg group, there was no significant difference in any measurement items compared with the control group. In the 1000 mg / kg group, a significant lower value of MCHC was found compared to the control group, but it was judged that it is a mild difference and not based on administration.

Clinical biochemistry findings:

effects observed, non-treatment-related

Description (incidence and severity):

In the 30 and 100 mg / kg group, there was no significant difference in any of the measurement items compared to the control group. In the 300 mg / kg group, a significant high value of β - globulin rate was found compared with the control group. In the 1000 mg / kg group, compared to the control group, there was a significant increase in GPT, γ-GTP, α 2 -globulin ratio, β-globulin ratio and total high bilirubin value, albumin amount, α 1 -globulin rate, α 3 -globulin rate and blood glucose Significantly low values were observed.

Urinalysis findings:

not specified

Behaviour (functional findings):

not specified

Immunological findings:

not specified

Organ weight findings including organ / body weight ratios:

effects observed, non-treatment-related

Description (incidence and severity):

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:

effects observed, non-treatment-related

Description (incidence and severity):

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:

effects observed, non-treatment-related

Description (incidence and severity):

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

Effect levels

Dose descriptor:

NOAEL

Effect level:

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

Based on:

test mat.

Sex:

male/female

Basis for effect level:

body weight and weight gain

clinical biochemistry

clinical signs

food consumption and compound intake

gross pathology

haematology

histopathology: non-neoplastic

mortality

organ weights and organ / body weight ratios

Remarks on result:

other: No effect observed

Target system / organ toxicity

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

Applicant's summary and conclusion

Conclusions:

NOAEL was considered to be 1000 mg/kg bw when Sprague-Dawley male and female rats were treated with Divinylbenzene orally by gavage for day 50 in male and till day 4 of lactation for female.

Executive summary:

In a c Combined Repeat Dose and Reproductive / Developmental Toxicity Screening Test, Sprague-Dawley male and female rats were treated with Divinylbenzene in the concentration of 0, 30, 100, 300 and 1000 mg/kg bw orally by gavage for day 50 in male and till day 4 of lactation for female. 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. Death and moribund cases were not observed in either group in male rat. One case of death and one case of moribund were observed in the 1000 mg / kg group in female rats. The body weights at 30 and 100 mg / kg group were almost the same as those of the control group. In the 300 mg / kg group, the body weight was significantly lower on the 8^thday 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. The food consumption of the 30 mg / kg group was almost the same as that of the control group. 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 34th 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. Similarly, In the 30 mg / kg group, a significant high value of erythrocyte count was seen compared with the control group, but it was judged that it was not a dose dependent change and not based on administration. In the 100 and 300 mg/ kg group, there was no significant difference in any measurement items compared with the control group. In the 1000 mg / kg group, a significant lower value of MCHC was found compared to the control group, but it was judged that it is a mild difference and not based on administration. In the 30 and 100 mg / kg group, there was no significant difference in any of the measurement items compared to the control group. In the 300 mg / kg group, a significant high value of β - globulin rate was found compared with the control group. In the 1000 mg / kg group, compared to the control group, there was a significant increase in GPT, γ-GTP, α 2 -globulin ratio, β-globulin ratio and total high bilirubin value, albumin amount, α 1 -globulin rate, α 3 -globulin rate and blood glucose significantly low values were observed. In addition, 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. 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 fore stomachial 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. 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. Therefore, NOAEL was considered to be 1000 mg/kg bw when Sprague-Dawley male and female rats were treated with Divinylbenzene orally by gavage for day 50 in male and till day 4 of lactation for female.