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Toxicological information

Acute Toxicity: dermal

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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:
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

Reference
Name:
Unnamed
Type:
Constituent
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 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:
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.

Body weight:
Animals gained weight normally.
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.