"In any amount? Then I'm not sure anything is safe by that definition. Also you'd likely need to define "adverse". > proving that is impossible with any current method of testing food safety. Irrelevant. We're not talking about current methods, we're talking about what's possible which allows for any method. > at that level of pedantry It's simple logic which parent got wrong, not mere pedantry. It matters in part because it affects many more situations than just this one. It's basic reasoning which is what we're supposed to be doing better than most. It may require crazy resources we don't have to pull off in the near future, but it needn't be done in the near future." - Tanath