9-Octadecenoic acid (Z)-, isooctyl ester, reaction products with glycerol trioleate and sulfur

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 following a methodology equivalent to that outlined in the standardised guideline OECD 406 using the Buehler Method. During the study, 0.3 mL test material was applied, unchanged, to the shaved backs of ten male guinea pigs once a week for three weeks. Ten control guinea pigs were handled in the same manner but were not treated with the test material. Two weeks following the induction period, the treated and control animals received a challenge dose of 0.3 mL of undiluted test material. All animals were scored for erythema 24 and 48 hours following the first application of induction dose and of the challenge dose. Erythema scores of 2 were observed in five treated and four control animals 24 hours after the challenge dose. An erythema score of 2 is usually considered a positive indication of a sensitisation response, however, since an erythema score of 2 was seen in approximately the same number of control animals as treated animals following challenge, the erythema was considered to have been caused by test material irritation, rather than indicating a true sensitisation response. The presence of test material-related dermal irritation therefore prevented the assessment of a weak sensitisation response, however, since moderate to severe erythema was seen in only one treated animal, the test material did not appear to induce a moderate or strong dermal sensitisation response during the study. Therefore, the test material is considered to be unlikely to be a skin sensitiser.

In a further study, the skin sensitisation potential of the test material was determined following a methodology equivalent to that outlined in standardised guidelines OECD 406, EPA OPP 81-6 and EPA OPPTS 798.4100 using the Buehler Method. During the study, 0.3 mL test material was applied, unchanged, to the shaved backs of 20 guinea pigs once a week for three weeks. Two groups of control guinea pigs were handled in the same manner but were not treated with the test material. Two weeks following the induction period, the treated and the challenge control animals received a challenge dose of 0.3 mL of undiluted test material. Six days after challenge exposure, the treated and the re-challenge control animals received a re-challenge dose of 0.3 mL test material. All animals were scored for erythema 24 and 48 hours following the first application of induction dose and following the challenge, and re-challenge, doses. Following primary challenge, the incidence of grade 1 responses in the test group (5 of 20) was compared to that of the control group (0 of 8). The incidence of these responses in the test group was greater than that produced in the control group suggesting that sensitisation might have been induced. However, it should be noted that the grade 1 responses in the test group were evident at the 24 hour reading only and had reduced to grade ± responses at the 48 hour reading. Therefore, a re-challenge was conducted to more clearly define if the grade 1 responses were indicative of sensitisation or a result of primary irritation.

Following re-challenge, the incidence of grade 1 responses in the test group (2 of 20) was compared to that of the control group (3 of 10). The incidence and severity of these responses in the test group were now less than those produced by the control group indicating that sensitisation had not been induced. Therefore, under the conditions of the study, the test material was determined to be not sensitising.

Both studies presented to assess the skin sensitisation potential of the test material were performed in line with GLP and to method equivalent to those outlined in accepted standardised guidelines with a high standard of reporting. Both studies were assigned a reliability score of 1 in accordance with the criteria for assessing data quality as outlined in Klimisch (1997).

Migrated from Short description of key information:
Not sensitising - Buehler Method, Johnson (1992) and Morris (1994).

Justification for selection of skin sensitisation endpoint:
The two studies that are available are considered to be acceptable and have been allocated a reliability score of 1 and so both are considered to be key studies.

Respiratory sensitisation

Endpoint conclusion

Endpoint conclusion:

no study available

Justification for classification or non-classification

In accordance with with criteria for classification as defined in Annex I, Regulation 1272/2008, the test material does not require classification for skin sensitisation.