4-tert-Butoxystyrene

Acute Toxicity: oral

Administrative data

Endpoint:

acute toxicity: oral

Type of information:

experimental study

Adequacy of study:

key study

Study period:

2008

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2008

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

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

Version / remarks:

2001

Deviations:

no

GLP compliance:

yes

Test type:

acute toxic class method

Limit test:

yes

Test material

Test material information

Constituent 1

Reference substance name:

1-(tert-butoxy)-4-ethenylbenzene

EC Number:

619-127-3

Cas Number:

95418-58-9

Molecular formula:

C12H16O

IUPAC Name:

1-(tert-butoxy)-4-ethenylbenzene

Test material form:

liquid

Details on test material:

Clear and colourless

Test animals

Species:

rat

Strain:

Wistar

Sex:

female

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Source: Charles River Deutschland, Sulzfeld, Germany
- Females nulliparous and non-pregnant: yes
- Age at study initiation: approx. 9 weeks old
- Weight at study initiation: body weight variation did not exceed +/- 20% of the sex mean.
- Fasting period before study: overnight (for a maximum of 20 hours)
- Housing: 3 animals per cage in labelled macrolon cages containing sterilised sawdust bedding and paper as cage-enrichment.
- Diet: free access to pelleted rodent diet (SM R/M-Z).
- Water: free access to tap water.
- Acclimation period: at least 5 days.

ENVIRONMENTAL CONDITIONS
- Temperature (°C): 21 ± 3 °C.
- Humidity (%): 30-70%.
- Air changes (per hr): approx. 15 changes per hour.
- Photoperiod (hrs dark / hrs light): 12 h/12 h.

Administration / exposure

Route of administration:

oral: gavage

Vehicle:

unchanged (no vehicle)

Details on oral exposure:

MAXIMUM DOSE VOLUME APPLIED: 2000 mg/kg bodyweight

Doses:

2000 mg/kg bodyweight

No. of animals per sex per dose:

2 dose groups of 3 females.

Control animals:

no

Details on study design:

- Duration of observation period following administration: 14 days
- Frequency of observations and weighing: the animals were observed twice daily for mortality and viability. The rats were weighed on Day 1 (pre-administration), Day 8 and Day 15. Clinical signs were observed during periodic intervals on the day of dosing (Day 1) and once daily thereafter until Day 15.
- Necropsy of survivors performed: yes
- Other examinations performed: clinical signs, body weight

Results and discussion

Effect levels

Sex:

female

Dose descriptor:

LD50

Effect level:

> 2 000 mg/kg bw

Based on:

test mat.

Mortality:

No mortality occurred during the study.

Clinical signs:

other: Hunched posture and piloerection noted in all animals on Days 1 and 3. Lethargy, chromodacryorrhoea and/or watery discharge from the eye observed among the animals on Day 1 and/or 2.

Gross pathology:

No abnormalities were found at macroscopic post mortem examination of the animals.

Applicant's summary and conclusion

Interpretation of results:

GHS criteria not met

Executive summary:

The Acute Toxic Class Method was used for assessment of acute oral toxicity with butoxystyrene in the rat. Butoxystyrene was administered by oral gavage to two subsequent groups of three female Wistar rats at 2000 mg/kg body weight. Animals were subjected to daily observations and weekly determination of body weight. Macroscopic examination was performed after terminal sacrifice (Day 15).

No mortality occurred. Hunched posture and piloerection were noted in all animals between Days 1 and 3. Further, lethargy, chromodacryorrhoea and/or watery discharge from the eye was observed among the animals on Day 1 and/or 2. The body weight gain shown by the animals over the study period was considered to be normal. No abnormalities were found at macroscopic post mortem examination of the animals.

The oral LD50 value of butoxystyrene in Wistar rats was established to exceed 2000 mg/kg body weight.