ECHA’s Member State Committee has agreed to request a combined comet assay (OECD TG 489) and micronucleus test (OECD TG 474) for substances registered above one tonne per year under Annex VII to REACH.
The combination study will be requested if there is:
- a positive Ames test – which checks the potential of chemicals to create mutations in bacteria;
- an indication of a chromosomal aberration concern; and
- no other adequate and appropriate in vivo genotoxicity data available in the dossier.
This approach already applies to compliance checks and testing proposal examinations to fulfil information requirements for higher tonnage bands under REACH annexes VIII, IX and X. From now on, registrants can expect requests for a combination study also for Annex VII dossiers.
The combined study can help to reduce animal testing while providing useful information on the potential of substances to induce chromosomal aberrations or gene mutation in vivo.