Benzene, 1,4-bis(1-methylethyl)-, homopolymer

Acute Toxicity: oral

Administrative data

Endpoint:

acute toxicity: oral

Type of information:

experimental study

Adequacy of study:

key study

Study period:

2002-08-20 to 2002-09-11

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: GLP and guideline compliant

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2002

Report date:

2002

Materials and methods

Test guideline

Test guideline 1

Qualifier:

according to guideline

Guideline:

OECD Guideline 423 (Acute Oral toxicity - Acute Toxic Class Method)

Version / remarks:

(1996)

Deviations:

no

Test guideline 2

Qualifier:

according to guideline

Guideline:

EU Method B.1 (Acute Toxicity (Oral))

Version / remarks:

(1996)

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Test type:

acute toxic class method

Limit test:

no

Test material

Test material information

Constituent 1

Reference substance name:

-

EC Number:

449-400-0

EC Name:

-

Cas Number:

25822-43-9

Molecular formula:

C24H34

IUPAC Name:

1,1'-(2,3-dimethylbutane-2,3-diyl)bis[4-(propan-2-yl)benzene]

Test material form:

other: solid, fine scales

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 Deutschland GmbH, D-97633 Sulzfeld
- Age at study initiation: About 8 weeks
- Weight at study initiation: 6 Female about 116 g, 6 male about 132 g
- Housing: Single caging in Makrolon cages type III (39 cm x 23 cm x 18 cm). Wire mesh lids. Sanitation of the cages once a week.
- Diet: Altromin 1324 forte, gamma irradiated with 25 kGy 60Co, ad libitum (Producer: Altromin GmbH, D-32791 Lage). Exception: The feed was withdrawn the evening before the administration of the test substance and was offered again about three hours afterwards.
- Water: Tap water
- Acclimation period: 5 days

ENVIRONMENTAL CONDITIONS
- Temperature: 22 °C
- Humidity: 67.7 %
- Air changes: 12 per hour
- Photoperiod: Artificial light from 6 a.m. to 6 p.m.

Administration / exposure

Route of administration:

oral: gavage

Vehicle:

other: 0.1 % Na-carboxymethylcellulose plus 0.1 % Tween 80

Details on oral exposure:

MAXIMUM DOSE VOLUME APPLIED: 10 mL/ kg bw

DOSAGE PREPARATION: The test substance was ground in a mortar and suspended in 0.1 % CMC (carboxymethyl cellulose) plus 0.1 % Tween 80 in deionised water. The suspensions were prepared freshly before administration and were administered within 5 minutes after the preparation.

CLASS METHOD:
- Rationale for the selection of the starting dose: As no prior information on the toxicity of the test substance was available, a starting dose of 200 mg of the test item per kg body weight was chosen. The further proceeding was in accordance with the guideline/directive.

Doses:

male: 200 and 2000 mg/kg bw
female: 200 and 2000 mg/kg bw

No. of animals per sex per dose:

3/sex/dose

Control animals:

no

Details on study design:

- Duration of observation period following administration: 14 days
- Frequency of observations and weighing:
daily observation for clinical signs 0 - 0.5, 0.5 - 1, 1 -2, 2 - 4 and 4 - 6 hours after administration and at least once a day for a total of 2 weeks. Body weight measurements were done before administration and at day 7 and 14. Body weight gain was calculated for each week of the study.
- Necropsy of survivors performed: Yes. The animals were killed by 80 % CO2 + 20 % air 14 days post application and subjected to a necropsy including a gross pathological examination.
- Other examinations performed: clinical signs, body weight, organ weights, histopathology, feed consumption, haematology, clinical biochemistry.

Results and discussion

Effect levels

Sex:

male/female

Dose descriptor:

LD50

Effect level:

> 2 000 mg/kg bw

Based on:

test mat.

Mortality:

There was no mortality observed in either male or female rats in any dose.

Clinical signs:

other: No relevant signs of toxicity, only signs of discomfort, were observed up to 6 h post application in the high dosed group.

Gross pathology:

No relevant toxic effects on organs were observed

Other findings:

Slight reduction of plasma urea concentration in the high dosed females was observed.

Applicant's summary and conclusion

Interpretation of results:

not classified

Remarks:

Migrated information Criteria used for interpretation of results: EU

Conclusions:

No mortality and no toxic effects of the test item were observed during the study period. The test item is therefore not classified as "acute toxic" according to the Directive 67/548/EEC (DSD) and the Regulation (EC) No 1272/2008 (CLP).

Executive summary:

The aim of the study was to investigate acute toxic effects of the test item after a single peroral administration to Sprague-Dawley rats according to the OECD 423. Administration of 200 and 2000 mg/kg bw were performed once per gavage to 3 males and 3 females, respectively. No clinical signs of toxicity and no mortality were observed within the observation period of 14 days. The LD50 was estimated to be > 2000 mg/kg bw.