Resin acids and Rosin acids, reaction products with formaldehyde, calcium salts

Endpoint summary

Key value for chemical safety assessment

Skin sensitisation

Endpoint conclusion

Endpoint conclusion:

adverse effect observed (sensitising)

Additional information:

The test item Resin acids and rosin acids, reaction products with formaldehyde, calcium salts was assessed for its skin sensitizing potential using the Local Lymph Node Assay (LLNA) in mice (OECD 442B, GLP). Test item suspension at different concentrations

was prepared in the vehicle methyl ethyl ketone (MEK). The local lymph node assay is recommended by international test guidelines (e.g. OECD) as an animal test for predicting skin sensitization in humans and provides a rational basis for risk assessment. The basic principle underlying the LLNA is that sensitizers induce a primary proliferation of lymphocytes in the lymph node draining the application site. The ratio of proliferation in test item treated groups compared to that in vehicle controls is termed the Stimulation Index (S.I.). BrdU labeling is used to measure cell proliferation. For this purpose a local lymph node assay was performed using test item concentrations of 1, 2 and 5% (w/w; weight per weight). Doses based on previously performed two pretests in the same animal strain in which 12 mice in total were used. In the pre-tests the highest concentration that could be technically used was 25% (w/w).

Signs of systemic toxicity were not observed in the pre-tests. At the tested concentrations of 10 and 25% the animals showed signs of local irritation as confirmed by the ear weight measurements or ear thickness measurements, respectively. At least one of two animals in dose group 25% showed both increased ear weights > 25% and ear swellings > 25%. One animal in dose group 10% showed also ear swellings > 25%. In addition scaling and white test item residues were noted in both dose groups, while incrustations were only noted in dose group 25%. Animals in dose group 2.5 and 5% didn`t show increased ear weights or ear swellings > 25%. Scaling was observed in both dose groups prior sacrifice. Therefore the following dose levels were selected for the main study: 5%, 2% and 1% (w/w) in the vehicle MEK. A statistically significant and biologically relevant increase in BrdU labeling was observed for the high (5%) dose group. A statistically significant increase was also observed for the 2% and 5% dose groups in lymph node weights and lymph node cell count, while only the 5% dose group reached biological relevance. Furthermore, the cut-off-value for a positive response regarding the lymph node cell count index of 1.55 reported for BALB/c mice was exceeded in the 5% dose group (index of 2.4). As expected, a statistical and biological relevant increase in BrdU labelling, lymph node weight, lymph node cell count and ear weight measurement was determined in the positive control.

Migrated from Short description of key information:
A local lymph node assay performed with the substance showed a moderate potential for the induction of skin sensitization.

Respiratory sensitisation

Endpoint conclusion

Endpoint conclusion:

no study available

Justification for classification or non-classification

Dangerous Substance Directive (67/548/EEC)

The available studies are considered reliable and suitable for classification purposes under 67/548/EEC. As a result the substance is considered to be classified for skin sensitization under Directive 67/548/EEC, as amended for the 31st time in Directive2009/2/EG.

 

Classification, Labelling, and Packaging Regulation (EC) No. 1272/2008

The available experimental test data are reliable and suitable for classification purposes under Regulation 1272/2008. The effective threshold concentration is higher than 2%. As a result the substance is considered to be classified for skin sensitization under Regulation (EC) No. 1272/2008 in Category 1B (moderate potency), as amended for the third time in Directive (EC 618/2012).