Benzene, ethenyl-, ar-bromo derivs.

Acute Toxicity: inhalation

Administrative data

Endpoint:

acute toxicity: inhalation

Type of information:

experimental study

Adequacy of study:

supporting study

Study period:

6 to 8 November 1980

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: Study conducted in accordance with generally accepted scientific principles, possibly with incomplete reporting or methodological deficiencies, which do not affect the quality of the relevant results.

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

1980

Report date:

1980

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

other: Regulations of MTB, Code of Federal Regulations, Vol. 49, Part 173.343(2), 1976

Deviations:

not specified

Principles of method if other than guideline:

Two groups of 5 male Sprague-Dawley rats were exposed, whole body, to the material via inhalation at different but consecutive times. Target concentration was 2 mg/L. Nominal concetrations were 3.1 mg/L and 2.8 mg/L for the first and second group, respectively. The test material was nebulized into a a 37.5 L glass exposure chamber with a DeVilbsis continuous flow nebulizer. The test material was stored in refrigerator until the hour of exposure. The nebulization rate was maintained at 11.7 mg/min, while the air exchange rate within the chanber was maintained at 3.8 L/min for the first group. The nebulization rate was maintained at 10.0 mg/min, while the air exchange rate within the chanber was maintained at 3.6 L/min for the second group. Animals were observed during the 1 hour exposure and for 2 days thereafter. Body weights were recorded just prior to exposure and again on test days 2 and 3. No necropsy was performed.

GLP compliance:

no

Remarks:

but QA statement included in the report

Test type:

standard acute method

Limit test:

no

Test material

Test material information

Constituent 1

Reference substance name:

Benzene, dibromoethyl Benzene, ethenyl-, ar-bromo derivs.

EC Number:

603-094-7

Cas Number:

125904-11-2

Molecular formula:

C8 H6 Br2

IUPAC Name:

Benzene, dibromoethyl Benzene, ethenyl-, ar-bromo derivs.

Test material form:

liquid

Test animals

Species:

rat

Strain:

Sprague-Dawley

Sex:

male

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Source: Harlan Industries, Inc., Madison, Wisconsin
- Age at study initiation: 8 weeks
- Weight at study initiation: 292 to 319 g
- Housing: individually
- Diet (e.g. ad libitum): Purina Rat Chow ad libitum except during the 1 hour exposure
- Water (e.g. ad libitum): ad libitum except during the 1 hour exposure
- Acclimation period: at least 7 days

ENVIRONMENTAL CONDITIONS
Temperature controlled quarters (no more details available)

IN-LIFE DATES: From: 6 To: 8 November 1980

Administration / exposure

Route of administration:

inhalation

Type of inhalation exposure:

whole body

Vehicle:

not specified

Details on inhalation exposure:

Exposures were conducted in a 37.5 L glass exposure chanber. Air flow through the chamber was provided with a wet test meter, and vacum pump. An air tube containing a desiccate was connected into the line of the air flow system between the exhaust port of the chamber and the wet test meter. This collected or filtered out the test material which was contained within the atmosphere that was exhausted from the chamber. The test material was administered into the chamber near the junction of the air inlet port, which usually allows the test material and incoming air to mix evenly within the chamber at the top before being drawn down and around the animals.

Analytical verification of test atmosphere concentrations:

no

Duration of exposure:

1 h

Concentrations:

Target 2 mg/L. Nominal 3.1 and 2.8 mg/L.

No. of animals per sex per dose:

5 males per group

Control animals:

no

Details on study design:

Animals were examined during the 1 hour exposure and for 2 days therefater. Body weight was recorded prior to exposure and on days 2 and 3. No necropsy was performed.

Statistics:

None

Results and discussion

Effect levels

Sex:

male

Dose descriptor:

LC50

Effect level:

> 2 mg/L air (nominal)

Exp. duration:

1 h

Remarks on result:

other: target concentration

Mortality:

No mortality occurred.

Clinical signs:

other: Reactions during exposure included lacrimation, clear nasal discharge, inactivity, and rapid, shallow breathing. All animals appeared normal in the afternoon following exposure and during the 2-day observation period.

Body weight:

Mean body weights showed an increase in both groups during the 3 days of test. Individual values showed minimal body weight losses in 3 rats of the first group on day 2, followed by body weight gains on day 3.

Gross pathology:

Not applicable

Applicant's summary and conclusion

Interpretation of results:

other: not a Class "B" poison

Remarks:

Criteria used for interpretation of results: other: Regulations of MTB, Code of Federal regulations, Vol. 49, Part 173.343(2), 1976

Conclusions:

The acute inhalation LC50 (1 hour) of dibromostyrene was higher than 2 mg/L (target concentration).

Executive summary:

In an acute inhalation study, two groups of 5 male rats were exposed whole-body to a target concentration of 2 mg/L. Nominal concetrations were 3.1 and 2.8 mg/L, respectively, for the first and second group. Animals were observed during exposure and for 2 days thereafter. Body weight was recoded prior to exposure and on days 2 and 3. No necropsy was performed.

No mortality occurred. Reactions during exposure included lacrimation, clear nasal discharge, inactivity, and rapid, shallow breathing. All animals appeared normal in the afternoon following exposure and during the two days after exposure. Mean body weight increased duirng the 3 days of test.

The LC50 (1 hour) of dibromostyrene was greater than 2 mg/L (target concentration).