Reaction mass of m,alpha-dimethylstyrene and p,alpha-dimethylstyrene

Acute Toxicity: oral

Administrative data

Endpoint:

acute toxicity: oral

Type of information:

experimental study

Adequacy of study:

key study

Study period:

17 October 1994 - 24 November 1994

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

1994

Report date:

1994

Materials and methods

Test guideline

Test guideline 1

Qualifier:

according to guideline

Guideline:

OECD Guideline 401 (Acute Oral Toxicity)

Version / remarks:

24 Februari 1987

Test guideline 2

Qualifier:

according to guideline

Guideline:

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

GLP compliance:

yes

Test type:

acute toxic class method

Limit test:

yes

Test material

Test material information

Constituent 1

Reference substance name:

Reaction mass of m,alpha-dimethylstyrene and p,alpha-dimethylstyrene

EC Number:

909-129-5

Molecular formula:

C10H12

IUPAC Name:

Reaction mass of m,alpha-dimethylstyrene and p,alpha-dimethylstyrene

Test material form:

liquid

Details on test material:

Indentification: m/p- isopropenyl toluene
Appearance: clear colourless liquid
Storage condition: room temperature
Purity: Not specified

Test animals

Species:

rat

Strain:

Sprague-Dawley

Sex:

female

Details on test animals or test system and environmental conditions:

- Source: Charles River (UK) Ltd., Margate, Kent, U.K.
- Age at study initiation: Young adult animals (approx. 5 to 8 weeks old)
- Weight at study initiation: 131 - 154 g for females, 148 - 175 g for males
- Fasting period before study: Overnight.
- Housing: Group housing of 5 animals per cage by sex in solid floor polypropylene cages furnished with woodflakes in labeled Macrolon cages.
- Diet: Free acces to Food (Rat and Mouse Expanded Diet No.l, Special Diets services Limited, Witham, Essex, U.K.).
- Water: Free access to tap water.
- Acclimation period: At least 5 days

ENVIRONMENTAL CONDITIONS
- Temperature (°C): 19 – 21
- Humidity (%): 48 - 56
- Air changes (per hr): approx 15
- Photoperiod (hrs dark / hrs light): 12/12


IN-LIFE DATES: From: 17 October 1994 to 24 November 1994

Administration / exposure

Route of administration:

oral: gavage

Details on oral exposure:

GAVAGE METHOD: metal cannula attached to a graduated syringe.

Frequency: single dosage, on day 1.


MAXIMUM DOSE VOLUME APPLIED:
2.25 mL/kg body weight.
Specific gravity: 0.891


DOSAGE PREPARATION:
The test material was used as supplied.

Range finding study (limit test):
In a range finding study, using a dose of 2000 mg/kg body weight for 1 male and 1 female rat resulted in no deaths.
Based on this information, a dose level of 2000 mg/kg body weight was selected for the main study.

Doses:

2000 mg/kg body weight.

No. of animals per sex per dose:

5

Control animals:

no

Details on study design:

Study Design:

- Duration of observation period following administration: 14 days.
- Body weight measurements: Body weights were recorded prior to dosing and on days 7 and 14.
Observations of clinical signs and mortality: At 30 minutes, 1 hour, 2 and 4 hours after administration and thereafter once daily.
- Necropsy of survivors performed: At the end of the study the animals were killed by cervical dislocation and subjected to gross pathological examination. This consisted of an external examination and opening of the abdominal and thoracic cavities.
- Other examinations performed: none.

Statistics:

No statistical analysis was performed.

Results and discussion

Effect levels

Key result

Sex:

male/female

Dose descriptor:

LD50

Effect level:

> 2 000 mg/kg bw

Based on:

test mat.

Mortality:

No deaths occurred.

Clinical signs:

Common signs of systemic toxicity noted were ataxia, hunched posture, lethargy, pilo-erection, decreased respiratory rate and laboured respiration with incidents of loss of righting reflex and splayed gait. Animals recovered one, two or five days after dosing. Four animals showed no clinical signs throughout the study.

Body weight:

All animals showed expected gain in body weight during the study.

Gross pathology:

No abnormalities were found at necropsy.

Applicant's summary and conclusion

Interpretation of results:

GHS criteria not met

Conclusions:

In an acute oral toxicity study with rats, performed according to OECD test guideline 401 and GLP principles, an LD50 >2000 mg/kg bw was determined and therefore the test item is not classified for oral toxicity according to GHS and CLP criteria.

Executive summary:

An assessment of acute oral toxicity with m/p - Isopropenyl toluene in rats was performed according to OECD test guideline 401 and GLP principles. The test item was administered by oral gavage to 5 male and 5 female Sprague Dawley rats at 2000 mg/kg body weight. No animals died throughout the 14 days observation period. Clinical signs that were observed were ataxia, hunched posture, lethargy, pilo-erection, decreased respiratory and laboured respiration with incidents of loss of righting reflex and splayed gait. Animals recovered one, two or five days after dosing except for four animals which appeared normal throughout the study. Body weight showed the expected gain and at necroscopy assessment no abnormalities were found. An LD50 >2000 mg/kg body weight was determined for the test substance and therefore m/p - Isopropenyl toluene does not need to be classified according to CLP and GHS regulations for oral toxicity.