Aniline

Endpoint summary

Key value for chemical safety assessment

Skin sensitisation

Endpoint conclusion

Additional information:

The skin sensitizaton potential of aniline was investigated in a study using three different protocols with 10 guinea pis in each treatment and 4 in each control group (Goodwin et al., 1981). No skin sensitization could be detected in a modified Draize test. A positive reaction in 1 of 10 animals was seen in the Magnusson Kligman test. The strongest response was observed in a Single Injection Adjuvant test (SIAT). Following repeated challenges, positive reactions were reported for 5 of 10 guinea pigs. A high sensitization rate of 90% was observed in a guinea pig maximization test when 0.5% aniline was used for intradermal induction and undiluted aniline for topical induction and for challenge (Basketter and Scholes, 1992).

In the mouse LLNA no (Haneke et al., 2001) or only weak skin sensitization potential (Basketter and Scholes, 1992, Gerberick et al., 2005) was observed for aniline. The concentration (EC3) necessary to induce a threefold stimulation index (SI) was determined with > 50 and 89% aniline, respectively.

In humans a mild positive response has been reported in a maximization test on 25 volunteers (Kligman, 1966), and in patch tests in patients suffering from eczematous dermatitis (Angelini et al., 1975, ECB, 2004). The positive reactions are often associated with para-group compound cross reactivity. This was also shown in a retrospective analysis of clinical data collected in a contact allergy surveillance network (IVDK, www.ivdk.org) between 01/1992 and 06/2004 and review of pertinent literature (Uter et al., 2007). The authors draw the conclusion that based on clinical data it is unlikely that aniline is an independent sensitizer of current importance. However, it may elicit allergic reactions in subjects pre-sensitized of para-substituted amino compounds. They summarised that is appears probable on the available animal data that aniline is a weak allergen.

Justification for classification or non-classification

According to a weight of evidence analysis of skin sensitization data aniline can be regarded as a weak skin sensitizer. Positive reactions in humans are often associated with para-group compound cross reactivity.

In accordance with the criteria for classification and labelling in Annex VI to 67/548/EEC, based on animal and human data, aniline is classified as skin sensitizer and labelled with the R-phrase R 43 “May cause sensitisation by skin contact”.

In accordance with the criteria for classification in the 2nd ATP of the CLP regulation (EC) 1272/2008 (286/2011) aniline is classified as skin sensitizer category 1B.