1,2-dihydro-5-nitro-3H-1,2,4-triazol-3-one

Endpoint summary

Key value for chemical safety assessment

Skin sensitisation

Link to relevant study records

Reference

Endpoint:

skin sensitisation: in vivo (non-LLNA)

Remarks:

in vivo

Type of information:

experimental study

Adequacy of study:

weight of evidence

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: Study run to a detailed method. Not GLP.

Qualifier:

no guideline followed

Principles of method if other than guideline:

Ten female guinea pigs were used in the treatment group. The compound was administered in a series of ten "sensitizing" injections into the lower back and flanks of the guinea pigs. Two weeks after administration of the tenth sensitizing injection, a challenge injection of 0.05 mL was administered. The volume of the first injection was 0.05 mL and that of the other nine was 0.10 mL.

GLP compliance:

not specified

Type of study:

other: K. Landsteiner and J. Jacobs, "Studies on the Sensitization of Animals with Simple Chemical Compounds," J. Exp. Med. 61, 643-656 (1935).

Justification for non-LLNA method:

Study conducted in 1985 prior to adoption of the LLNA test as the default testing method.

Specific details on test material used for the study:

Batch No.: not specified
Purity: not specified

Species:

guinea pig

Strain:

not specified

Sex:

female

Details on test animals and environmental conditions:

TEST ANIMALS
- Weight at study initiation: 363-438 g
- Housing: The animals were housed individually.
- Diet (e.g. ad libitum): The animals were fed commercial laboratory stock diet ad libitum supplemented by daily lettuce, cabbage, or apples because of their need for dietary fiber.

No additional data

Route:

intradermal

Vehicle:

corn oil

Concentration / amount:

0.1%

Route:

intradermal

Vehicle:

corn oil

Concentration / amount:

0.1%

No. of animals per dose:

10

Details on study design:

MAIN STUDY
A. INDUCTION EXPOSURE
- No. of exposures: 10
- Test groups: ten female animals
- Site: lower back and flanks
- Duration: 24 hours
- Concentrations: The volume of the first injection was 0.05 mL and that of the other nine was 0.10 mL .

B. CHALLENGE EXPOSURE
- No. of exposures: 1
- Day(s) of challenge: Two weeks after the topical induction.
- Exposure period: 24 hours
- Test groups: ten female animals
- Site: lower back and flanks
- Concentrations: 0.05 mL

No additional data

Challenge controls:

None stated

Positive control substance(s):

not specified

Key result

Group:

test chemical

Dose level:

0.1%

Total no. in group:

10

Remarks on result:

other: Review of the data collected for each guinea pig in the treatment group indicates that all challenge injections were within the limits of the reactions recorded during the sensitizing period.

Remarks:

The guinea pig skin sensitization study did not show NTO to be a sensitizer.

Review of the data collected for each guinea pig in the treatment group indicates that all challenge injections were within the limits of the reactions recorded during the sensitizing period. The guinea pig skin sensitization study did not show the test substance to be a sensitizer.

Interpretation of results:

not sensitising

Remarks:

Migrated information Criteria used for interpretation of results: EU

Conclusions:

The material did not induce sensitization in the intradermal guinea pig assay.

Endpoint conclusion

Endpoint conclusion:

no adverse effect observed (not sensitising)

Additional information:

An intradermal guinea pig assay on NTO was carried out (London and Smith, 1985). Ten female guinea pigs were treated with concentrations of 0.1% NTO in corn oil. The compound was administered in a series of ten sensitizing injections into the lower back and flanks of the guinea pigs. Injections were made randomly over the test area. Twenty four hours after injection the reaction was scored for erythema and swelling. Two weeks after administration of the tenth sensitizing injection, the lower back and flanks of each guinea pig were clipped free of hair and a challenge injection of 0.05 mL was administered. The reaction of each animal was graded 24 hr later and compared with those from the sensitising injections. All challenge injections were within the limits of the reactions recorded during the sensitizing period. Therefore NTO was not shown to be a skin sensitizer.

Migrated from Short description of key information:

The guinea pig skin sensitisation study did not show NTO to be a skin sensitiser.

Justification for selection of skin sensitisation endpoint:

The study was run to a detailed, scientific method though not to GLP.

Respiratory sensitisation

Endpoint conclusion

Endpoint conclusion:

no study available

Justification for classification or non-classification

NTO is not classified as a skin sensitizer as the skin sensitization study provided a negative result.