Nitromethane

Acute Toxicity: dermal

Administrative data

Endpoint:

acute toxicity: dermal

Type of information:

experimental study

Adequacy of study:

key study

Study period:

23 June 1980 - 14 July 1980

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: The study was not conducted according to guidelines but was conducted according to GLPs and the report contains sufficient data for interpretation of study results

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

1982

Report date:

1982

Materials and methods

Test guideline

Qualifier:

equivalent or similar to guideline

Guideline:

OECD Guideline 402 (Acute Dermal Toxicity)

Deviations:

yes

Remarks:

test material was applied to abraded skin (one female tested with intact skin)

Principles of method if other than guideline:

Test material was applied to the skin for 24 hours under an impervious rubberized cloth. Animals were observed for 14 days following exposure.

GLP compliance:

no

Test type:

standard acute method

Limit test:

yes

Test material

Test material information

Constituent 1

Reference substance name:

Nitromethane

EC Number:

200-876-6

EC Name:

Nitromethane

Cas Number:

75-52-5

Molecular formula:

CH3NO2

IUPAC Name:

nitromethane

Details on test material:

Purity of the test material was 95.88%. The test material also contained 3.31% nitroethane, 0.55% 2-nitropropane and 0.023% water. Other minor impurities were not listed.

Test animals

Species:

rabbit

Strain:

New Zealand White

Sex:

male/female

Details on test animals or test system and environmental conditions:

The animals were at least 9 weeks old and weighed at least 2 kg. They were acclimated for 7 days before use. Twenty four hours before the test, each animal was examined. Only animals with no skin injury were used. The animals were given food and tap water ad libitum.

Administration / exposure

Type of coverage:

occlusive

Vehicle:

unchanged (no vehicle)

Details on dermal exposure:

The test material (at 2000 mg/kg) was applied over a shaved area of abdominal skin and covered with a gauze patch and an impervious rubberized cloth. The dressings were removed after 24 hours.

Duration of exposure:

24 hours

Doses:

2000 mg/kg

No. of animals per sex per dose:

Probe study had one maile with abraded skin and and one female with intact skin.

Main study had 10 males and 5 females with abraded skin .

Control animals:

not specified

Details on study design:

A preliminary test was conducted with one male with abraded skin and one female with intact skin. The test material (at 2000 mg/kg) was applied over a shaved area of abdominal skin and covered with a gauze patch and an impervious rubberized cloth. The dressings were removed after 24 hours, and the animals were observed for toxicity over 14 days.

Since neither of the animals died, the study was repeated with 5 animals/sex, with abraded skin. The dressings were removed after 24 hours, and the sites of application were examined for erythema and edema. The animals were observed for toxicity over 14 days. Body weights were recorded prior to application of material and at 7 and 14 days. Complete necropsies were performed on animals that died. Gross necropsies were performed on all rabbits euthanized on day 14. Since one of the males died early on in the study, a second group of 5 males was added to the study.

Statistics:

If possible, LD50 value, slope and 95% confidence limits were calculated using the probit analysis of Finney (Cambridge Press, 1979) adapted to a BASIC computer program.

Results and discussion

Preliminary study:

Both rabbits dermally exposed to nitromethane in the probe study survived.

Effect levels

Sex:

male/female

Dose descriptor:

LD50

Effect level:

> 2 000 mg/kg bw

Based on:

test mat.

Mortality:

In the main study, one of five male and zero of five female rabbits dosed with 2000 mg/kg died. The only death occurred on day 4. The animal that died had evidence of a lung infection and discharge around the nose. Therefore a second group of five male rabbits were dosed with test material at the same dose; zero of five male rabbits died.

Clinical signs:

other: There was no evidence of dermal irritation noted in male or female rabbits. Discharge around the nose was observed in one male and one female.

Gross pathology:

The animal that died had evidence of a lung infection.

Other findings:

None of the animals had evidence of skin irritation and the abrasions healed by 14 days.

Any other information on results incl. tables

No additional information available.

Applicant's summary and conclusion

Interpretation of results:

Category 4 based on GHS criteria

Remarks:

Migrated information

Conclusions:

The dermal LD50 is >2000 mg/kg.

Executive summary:

The acute dermal LD50 for nitromethane in rabbits was examined.

One of 11 male rabbits and 0 of 6 female rabbits died following dermal exposure for 24 hours. The dermal LD50 is >2000 mg/kg.