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:
Migrated from Short description of key information:
Skin sensitization in vivo was tested using the local lymph node assay in the mouse for FLL Samples 3 and 4. According to the test results, both samples would be considered weak sensitizers with a Stimulation Index (SI) > 3 at 50% and 100% test concentrations. However, based on the following discussion, it is expected that these results were likely to have been “false-positives”.
Briefly, FLL Samples 3 and 4 produced maximum SI values of 4.81 and 3.85, respectively. While these are both ≥ 3 and could warrant a label of skin sensitization, guidance from OECD (2002) and EC (2008) state that a weight-of-evidence approach is warranted. The fatty acid components of FLL Samples 3 and 4 are naturally occurring compounds, and linoleic acid is an essential human fatty acid (Burr et al. 1932). FLL Sample 4 showed a weak dose-response relationship, where the 100% concentration produced less of a response than the 50% concentration. Several of the raw (unreacted) oils for both of these compounds have been shown to produce a positive result with LLNA and a negative result with GPMT (Kreiling et al. 2008). Given the addition of a sulfonate group is not a chemical predictor for skin sensitization (Barratt et al. 1994), the false positive findings of the oils tested by Kreiling et al. (2008) are applicable to the sulfonated components of the FLL Substances.
Therefore, the weakly positive responses for these tests should not result in a classification as a skin sensitizer for the FLL Substances.

Justification for classification or non-classification

Skin sensitizationin vivowas tested using the local lymph node assay in the mouse for FLL Samples 3 and 4. According to the test results, both samples would be considered weak sensitizers with a Stimulation Index (SI) > 3 at 50% and 100% test concentrations. However, based on the following discussion, it is expected that these results were likely to have been “false-positives”.

Briefly, FLL Samples 3 and 4 produced maximum SI values of 4.81 and 3.85, respectively. While these are both≥3 and could warrant a label of skin sensitization, guidance from OECD (2002) and EC (2008) state that a weight-of-evidence approach is warranted. The fatty acid components of FLL Samples 3 and 4 are naturally occurring compounds, and linoleic acid is an essential human fatty acid (Burret al. 1932). FLL Sample 4 showed a weak dose-response relationship, where the 100% concentration produced less of a response than the 50% concentration. Several of the raw (unreacted) oils for both of these compounds have been shown to produce a positive result with LLNA and a negative result with GPMT (Kreilinget al.2008). Given the addition of a sulfonate group is not a chemical predictor for skin sensitization (Barrattet al.1994), the false positive findings of the oils tested by Kreilinget al.(2008) are applicable to the sulfonated components of the FLL Substances.

Therefore, the weakly positive responses for these tests should not result in a classification as a skin sensitizer for the FLL Substances.