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:

A local nymph node assay (LLNA) study was carried out with Silicon Nitride according to OECD Guideline 429 and EC method B.42 and in accordance with GLP (Huntingdon Life Sciences, 2012). The study comprised 3 treatment groups each of 4 female rats receiving Silicon Nitride at concentrations of 10, 25 or 50% w/v. Similar groups received vehicle (dimethylformamide) or positive control substance. Mice were treated by the daily application of 25 µL of the appropriate concentration or control to the dorsal surface of both ears for three consecutive days. The proliferative response of the lymph node cells (LNC) from the draining auricular lymph nodes was assessed five days following the initial application by measurement of the incorporation of 3H-methyl thymidine (3HTdR) by scintillation counting of LNC suspensions. The response was expressed as radioactive disintegrations per minute per lymph node (dpm/node) and as the ration of 3HTdR incorporation into LNC of test nodes relative to that recorded for control nodes (test/control ratio), termed as Stimulation Index (SI). The test substance is regarded as sensitiser if at least one concentration of the chemical has a SI of 3 or more. The SI obtained for 10, 25 & 50% w/v of Silicon Nitride were 0.8, 1.2 & 1.5 respectively which indicates that Silicon Nitride did not show the potential to induce skin sensitisation.


Migrated from Short description of key information:
The Stimulation Index (SI) for 10, 25 & 50% of test substance were 0.8, 1.2 and 1.5 respectively which indicates that Silicon Nitride did not show the potential for skin sensitisation.

Justification for selection of skin sensitisation endpoint:
The study was undertaken to internationally accepted guidelines and to GLP.

Respiratory sensitisation

Endpoint conclusion
Endpoint conclusion:
no study available

Justification for classification or non-classification

According to the local lymph node assay conducted, Silicon Nitride shoudl not be classified for skin sensitisation.