Registration Dossier

Administrative data

Description of key information

The result of SENS-IS test is clearly positive and no further investigation is deemed necessary.

Key value for chemical safety assessment

Skin sensitisation

Endpoint conclusion
Endpoint conclusion:
adverse effect observed (sensitising)
Additional information:

The potential of Tetraphosphorus trisulphide to induce the expression of specific irritation and sensitization biomarkers in a 3D-reconstructed epidermis model was evaluated according to SENS-IS method. Considering the number of over-expressed gene in "ARE" gene groups, the test item " gave positive results (more than 6 genes induced) after application of crude powder onto the epidermis. In conclusion, under the experimental conditions of the SENS-IS assay, the test item Tetraphosphorus trisulphide was classified as skin sensitiser. Since the test item could not be tested at the classical concentrations of the assay (not soluble), it was not possible to evaluate the degree of sensitization in this assay.

Even though the OECD Guideline of SENS-IS method is under validation, SENS-IS method is already included among the in vitro tests to investigated the skin sensitisation potential of a substance in ECHA guidance R7a (July 2017). SENS-IS has the potential to serve as a stand-alone method regarding the classification of test item as skin sensitiser. It was not possible to test the skin sensitisation of this substance according to other validated OECD methods due to the low solubility of the test item in the common solvents used for biological tests. With SENS-IS assay was possible to test Tetraphosphorus trisulphide as solid substance.

Respiratory sensitisation

Endpoint conclusion
Endpoint conclusion:
no study available

Justification for classification or non-classification

According to the CLP Regulation (EC. n.1272/2008), Skin sensitiser means a substance that may trigger an allergic response following skin contact. The skin sensitisation potential of Tetraphosphorus trisulphide was investigated according to EU Regulation 2016/1688 - updated regarding skin sensitisation requirement of annex VII of the REACH regulation (EC. n. 1907/2006) in force since 11th October 2016. The biological mechanisms of skin sensitisation is a stepwise mechanism (Adverse Outcome Pathway -AOP) that follows these starting key events: (a) molecular interaction with skin proteins; (b) inflammatory response in keratinocytes; (c) activation of dendritic cells. SENS-IS test investigates the activation of keratinocytes . The result of SENS-IS on the substance was clearly positive and considering also some cases of sensitisation on humans the classification H317 is suggested for this substance. Since the test item could not be tested at the classical concentrations of the assay (not soluble), it was not possible to evaluate the degree of sensitization in this assay.