Precautionary principle leads to "may contain" clause for genetically modified foods.
Pinker
S
S
D005506:Food Contamination / Q000331:legislation & jurisprudence*; D005524:Food Technology / Q000331:legislation & jurisprudence*; D005818:Genetic Engineering / Q000331:legislation & jurisprudence*; D006801:Humans; D010945:Plants, Edible / Q000235:genetics*; D014480:United Nations