Non-graphitic carbon fibre

Endpoint summary

Key value for chemical safety assessment

Skin sensitisation

Link to relevant study records

Reference

Endpoint:

skin sensitisation: in vitro

Data waiving:

study scientifically not necessary / other information available

Justification for data waiving:

other:

Endpoint conclusion

Endpoint conclusion:

no study available

Respiratory sensitisation

Endpoint conclusion

Endpoint conclusion:

no study available

Justification for classification or non-classification

According to Annex XI(2) of the REACH Regulation "testing for a specific endpoint may be omitted if it is technically not possible to conduct the study as a consequence of the properties of the substance”. And furthermore, Annex VI, Note 1, of the REACH Regulation states: “If it is not technically possible or if it does not appear scientifically necessary to give information the reasons shall be clearly stated in accordance with the relevant provisions.” According to ECHA's Guidance on Information Requirements and Chemical Safety Assessment, Chapter R.7a: Endpoint specific guidance (May 2008), section R.7.3.1.3, “Mechanisms of immunologically-mediated hypersensitivity”, the following key steps are required for a chemical to induce sensitisation via skin contact: gaining access to the viable epidermis, protein binding, metabolic activation (if required), internalisation and processing by Langerhans cells (LC), transport of antigen by LC to draining lymph nodes, presentation to and recognition by T lymphocytes (cf. R.7a, p. 259). Non-graphitic carbon fibres within the scope of this registration are a relatively large solid material with a negligible solubility in water and as such they cannot penetrate the skin either by passive diffusion or active transport mechanisms. Consequently, gaining access to the viable epidermis, protein binding, and metabolic activation will not occur with carbon fibres covered by this registration, i.e. all other key steps mentioned above cannot be fulfilled. Therefore, skin sensitising properties of non-graphitic carbon fibres within the scope of this registration can be excluded based on scientific grounds. This assumption is supported by the results from a test with artificial body fluids (see IUCLID section 7.1.1). In this test, the carbon release from the substance was not distinguishable from the blank assuming that no carbon was released. The test substance (milled carbonised PAN based fibre) falls within the typical range of the substance definition including the impurities (in total < 0.3%) which in principle consist of metal and mixed metal oxides (mainly Al, Ca, Fe, Na, and Si oxides). These substances are of negligible concern regarding human health and the environment. In addition, no irritative properties to the skin have been found. The different manufacturing processes and precursor materials for non-graphitic carbon fibres within the scope of this registration lead to slightly different compositions. Accordingly, the choice of the test material is based on the substance with the highest content of nitrogen. Therefore, the obtained test results are regarded to also cover all other qualities of the substance non-graphitic carbon fibre within the scope of this registration. Based on the obtained test results, the explanation in ECHA's guidance document and following the provisions in Annex XI(2) and in Annex VI of the REACH Regulation the information requirement “skin sensitisation” is waived.