Registration Dossier

Administrative data

Description of key information

Key value for chemical safety assessment

Skin sensitisation

Endpoint conclusion
Endpoint conclusion:
no adverse effect observed (not sensitising)
Additional information:

TNPP (purity >99%) was tested in a local lymph node assay (LLNA) study (Sanders 2010) and none of the tested concentrations (25, 50, and 100%) produced a positive response (a three-fold increase in test/control ratio). These results are further supported by a OECD 406 Buehler assay of TNPP (purity >99%) conducted by Tay et al. (2001), which also found that TNPP is not a skin sensitiser.

The proposed Annex XV C&L harmonisation dossier for TNPP developed by France (December 2009) proposed that TNPP be classified as skin sensitiser based solely on the positive result in an older Guinea Pig Maximisation Test (GPMT) study conducted by Ciba-Geigy (Hagemann 1992). However, as discussed in the comments submitted by Dover Chemical (April 2010) during the consultation process, it has been well established that the GPMT can produce false positives and thusly the LLNA study was selected as primary study for the skin sensitisation endpoint under REACH. With the negative results of the LLNA study for TNPP now available, it clearly is inappropriate to classify TNPP as a skin sensitiser.


Migrated from Short description of key information:
The results of a new local lymph node assay (LLNA) study of TNPP (Sanders 2010) indicate that it is not a skin sensitiser.

Justification for classification or non-classification