Phenyl bis(2,4,6-trimethylbenzoyl)-phosphine oxide

Endpoint summary

Key value for chemical safety assessment

Skin sensitisation

Endpoint conclusion

Endpoint conclusion:

adverse effect observed (sensitising)

Additional information:

The test substance was investigated 1997 for sensitisation in the GPMT according to the OECD TG 406 (Huntingdon Life Sciences Ltd 964057). To account for the light sensitivity of the test substance, the test formulations were prepared under safelight and the formulation containers wrapped in aluminium foil. Aluminium foil was incorporated in the dressings to minimise photoinduced degradation of the test material. The test substance was prepared in 5% acetone in Alembicol D" (product of coconut oil) and acetone alone.
The concentrations of test substance used for the main study were selected based on the results of a range-finding test as follows: 1% w/v in 5% acetone in Alembicol D for intradermal induction, 70% w/v in acetone for epicutaneous induction, and 70 and 35 % w/v in acetone for epicutaneous challenge. In the main test, following intradermal and epicutaneous induction, the animals were challenged epicutaneously after 2 weeks. After challenge, 3/10 test animals gave positive responses. A further 4 animals gave inconclusive responses and the remaining 3 gave negative responses.

Another GPMT according to the OECD TG 406 (Ciba-Geigy Ltd 954087) was performed without the above prerequisites of light sensitivity and led to a stronger response, categorizing the substance as an extreme sensitizer.

Migrated from Short description of key information:
The test substance was investigated in two Guinea Pig maximization Tests (GPMT) according to the OECD TG 406 (1992); both studies were GLP-conform (Ciba-Geigy Ltd 954087 conducted 1996 and Huntingdon Life Sciences Ltd 964057 conducted 1997). In both studies, positive skin reactions following challenge were reported, indicating that the test substance has skin sensitizing properties.

Respiratory sensitisation

Endpoint conclusion

Endpoint conclusion:

no study available

Justification for classification or non-classification

In two Guinea pig maximization tests performed according to the OECD TG 406 (1992) the test substance induced skin sensitizing effects. In both studies, the percentage of positive responses was greater than 60% at intadermal induction concentrations of less or equal to 1%. Thus, the test substance has to be classified as R43 according to the EU Directive 67/548/EEC and as Category 1A “sensitizing” according to the European GHS Regulation (EC) No. 1272/2008 as amended for the fifth time in Directive EC944/2013.