I think you need to have a regulatory regime that periodically comes back to these reviews of substances, particularly where we have found them to be non-toxic on the basis of not very good evidence or not enough evidence. It's something you might have with respect to the pesticides management regime, where there's a periodic review that happens every few years so that we can get the benefit of the emerging knowledge.
On June 9th, 2016. See this statement in context.