As Silicon Carbide is mentioned in the ECHA report “Assessment of Regulatory Needs - Group Name: Simple inorganic Silicon (Si) compounds”, published 6 January 2023 SiCMa has carefully assessed this document.
From our point of view the report contains some obviously wrong statements and necessary distinctions are missing. We have communicated these shortcomings to ECHA and expect a correction in the coming weeks.
The main mistake concerns the missing distinction between SiC crude and grain on one side and SiC fibres on the other side.
The REACH registration for SiC concerns SiC crude and grain which is placed on the markets worldwide in high volumes. There is no scientific investigation that has identified any risk with SiC crude and grains. There is no classification for SiC crude and grains. There is no need for any regulatory action concerning SiC crude and grain.
Silicon Carbide fibres are excluded from the registration dossier, and they are - to our knowledge - not placed on the market. SiC fibres are classified as carc 1B concerning the risk for causing cancer. (see Annex VI of the REACH regulation). As SiC fibres do not occur on the market there is as well no need for regulatory action.
In the report also aquatic toxicity is addressed. Please be informed that for SiC aquatic toxicity tests have been done. Following these tests SiC is officially classified as non-hazardous to water in Germany.
No classification for SiC products (CAS 409-21-2)
Since March 2022, silicon carbide (SiC) fibres have a harmonized classification under the CLP Regulation. SiC fibres and cleavage fragments which fall within the World Health Organization (WHO) definition of a ‘fibre’ are classified as carcinogenic 1B. The WHO defines ‘fibres’ as particles with a length of >5µm, a diameter of <3µm and an aspect ratio (length/diameter) of >3:1.
This new classification does not concern SiC crude and grain (CAS 409-21-2). Customers of SiCMa members buying SiC crude and grain are therefore not affected by the new classification of SiC fibres.
SiC crude and grain has been extensively tested for the REACH registration dossier and is clearly classified as non-hazardous material.
The decision on the classification of fibres is based on scientific studies for whiskers. Nevertheless, ECHA and the EU Commission took a decision for all particles falling under the WHO definition, irrespective whether or not they showed adverse effects. SiCMa disagrees with this decision from a scientific perspective. Scientific studies undertaken by SiCMa and other publicly available information indicate that a differentiated view on SiC fibres is required. None of the scientific studies, to our knowledge, showed evidence that cleavage fragments and short fibres have carcinogenic effects. Only very long fibres, so-called ‘whiskers’ (diameter <1µm, length >10µm; aspect ratio >10) which are produced in a different way than SiC crude and grains may be considered carcinogenic.
Unfortunately, a source of confusion might be that SiC fibres have the same CAS number (CAS N° 409-21-2) as SiC crude and grain, although, this is a completely different material.
Please contact your SiC supplier in case of any further questions.