The European Food Safety Authority (EFSA) released a draft opinion, titled, “Reflection on interpretation of some aspects related to genotoxicity assessments,” and launched a public consultation on the draft opinion.

EFSA developed the draft opinion in response to a request from the European Commission (EC) for advice on the following:

1. The suitability of the unscheduled DNA synthesis in vivo assay to follow-up positive results in in vitro gene mutation tests;
2. The adequacy to demonstrate target tissue exposure in in vivo studies, particularly in the Mammalian Erythrocyte Micronucleus test; and
3. The use of data in a weight of evidence approach to conclude on the genotoxic potential of substances and the consequent setting of health-based guidance values.

For the first question, EFSA’s Scientific Committee (SC) concluded that the UDS test would not be recommended for future assessments; however, for re-assessments where there are negative results, other more reliable tests such as Transgenic Rodent assay or in vivo comet assay should be performed to complete the assessment.

Regarding the second question, the SC concluded that target tissue exposures should be addressed in both direct and indirect lines of evidence of bone marrow exposure, and that “[a]ll other direct or indirect lines of evidence of target tissue exposure should be assessed within a weight-of-evidence approach.”

Regarding the third question, the SC concluded that “any available data that may assist in reducing the uncertainty in the assessment of the genotoxic potential of a substance should be taken into consideration.”

Written comments should be submitted by September 6, 2017.