2-Pyridinesulfonamide, N-[[(4,6-dimethoxy-2-pyrimidinyl)amino]carbonyl]-3-(2,2,2-trifluoroethoxy)-, sodium salt (1:1)

Endpoint summary

Key value for chemical safety assessment

Skin sensitisation

Endpoint conclusion

Endpoint conclusion:

no adverse effect observed (not sensitising)

Additional information:

The skin sensitisation potential of the test material was determined in accordance with standardised guidelines OECD 406, EU Method B.6 and EPA OPP 81-6. In the Maximization test, three groups of 20 guinea pigs (vehicle control, test material and positive control) were included. On day 0, the animals were given a set of intradermal injections, including 1.0% test material in physiological saline for the test material group and 1.0 % 2-mercaptobenzothiazole in peanut oil for the positive control group. The epidermal application was made on day 8; the vehicle control animals were treated with vehicle alone, the test material group with 50 % test material in physiological saline and the positive control group with 50% 2-mercaptobenzothiazole in petroleum jelly. The epidermal challenge application on day 21 consisted of a paired application of the vehicle alone and either 10% test material in physiological saline or 10 % 2-mercaptobenzothiazole in petroleum jelly. Skin reactions on both the vehicle and test flanks were scored 24 and 48 hours after completion of the challenge application, according to the Draize scale.

 

There were no positive skin responses among either the vehicle control or test group animals on either the vehicle flank of the test flank; the sensitization rate for the test material was therefore 0 %. Positive reactions were observed in 10 males and 9 females in the positive control group on the test flanks at both the 24 and 48 hour examinations, corresponding to a sensitization rate of 95 %. Scaling was seen in seven males and five females at the 48 hour observation. There was no mortality, and there were no remarkable clinical observations in any group. Bodyweights were not affected by treatment.

 

In the Buehler Test, four groups of guinea pigs (10 vehicle control, 10 naive control, 10 positive control, and 20 test material) were included. On days 0, 7 and 14, animals received one 6-hour epidermal application of the distilled water vehicle (vehicle control group), 50 % test material in distilled water (test group), or 60 % positive control in peanut oil (positive control group). Naive control group animals were not treated. The challenge application on day 28 consisted of a paired application of vehicle alone and either 10 % test material in distilled water (test group) or 30 % positive control in peanut oil (positive control group). Skin reactions on both the vehicle and test flanks were scored 24 and 48 hours after completion of the challenge application, according to a modified Draize scale.

 

There were no positive skin responses among the vehicle control, naive control or test group animals on either the vehicle flank of the test flank; the sensitization rate for the test material was therefore 0 %. Positive reactions were observed in five of 10 animals on the test flank at the 24 hour reading in the positive control group and three animals at the 48 hour reading, corresponding to a sensitization rate of 50 %. There were no positive reactions on the vehicle flanks of the positive control group animals. There was no mortality, and there were no remarkable clinical observations in any group. Bodyweights were not affected by treatment.

 

 

Both studies were performed in line with GLP and accepted standardised guidelines with a high standard of reporting. The studies were assigned a reliability score of 1 in accordance with the criteria for assessing data quality as outlined in Klimisch (1997) and considered suitable for assessment as an accurate reflection of the test material.

 

The available data are considered to be complete and the conclusion, not sensitising, was taken forward for risk assessment.

Respiratory sensitisation

Endpoint conclusion

Endpoint conclusion:

no study available

Justification for classification or non-classification

In accordance with the criteria for classification as defined in Annex I, Point 3.4, Regulation 1272/2008, the test material did not elicit a response in either the Maximization Test or the Buehler Test and therefore does not meet the criteria for classification as a skin sensitiser.