2-Propyn-1-ol, compd. with 2-methyloxirane (1:?)

Endpoint summary

Key value for chemical safety assessment

Skin sensitisation

Endpoint conclusion

Endpoint conclusion:

no adverse effect observed (not sensitising)

Additional information:

The test item 2-Propyn-1-ol, compd. with methyloxirane was assessed for its skin sensitising potential using the Local Lymph Node Assay (LLNA) in mice according to OECD guideline 429 and GLP (Harlan, 2012). Test item solution at different concentrations was prepared in the vehicle dimethylformamide. 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 sensitisers 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.). Radioactive labelling is used to measure cell proliferation. For this purpose a local lymph node assay was performed using test item concentrations of 25, 50% (w/w), and 100% (undiluted test item). The animals did not show any signs of systemic toxicity or local skin irritation during the course of the study and no cases of mortality were observed. A statistically significant or biologically relevant increase in ear weights was not observed in any treated group in comparison to the vehicle control group. Furthermore, the cutoff-value for a positive response regarding the ear weight index of 1.1 reported for BALB/c mice was not exceeded in any dose group. A test item is regarded as a sensitiser in the LLNA if exposure to one or more test item concentration results in a 3-fold or greater increase in incorporation of 3HTdR compared with concurrent controls, as indicated by the Stimulation Index (S.I.). The estimated test item concentration required to produce a S.I. of 3 is referred to as the EC3 value. In this study Stimulation Indices (S.I.) of 0.60, 1.14, and 0.71 were determined with the test item at concentrations of 25, 50% (w/w) and 100% in dimethylformamide, respectively. An outlier was identified in the mid dose group (DPM value determined for animal number 14). However, as exclusion of the outlier did not change the overall test result, the value in question was not excluded from calculation. A statistically significant increase in DPM value, lymph node weight and also in lymph node cell count was not observed in any of the tested dose groups in comparison to the vehicle control group. Furthermore, the cutoff-value for a positive response regarding the lymph node cell count index of 1.55 reported for BALB/c mice was not exceeded in any dose group. The test item 2-Propyn-1-ol, compd. with methyloxirane was thus not a skin sensitiser under the test conditions of this study.

Migrated from Short description of key information:
LLNA (Harland, 2012): not sensitizing

Respiratory sensitisation

Endpoint conclusion

Endpoint conclusion:

no study available

Justification for classification or non-classification

Based on the LLNA, classification for skin sensitization is not warranted according to EU directive 67/548/EEC and EU classification, Labelling and Packaging of Substances and Mixtures (CLP) Regulation (EC) No. 1272/2008.