in order to crack down on the illegal addition of non-edible substances in food production, circulation and catering services, and protect consumers' health, the relevant state departments have published the List of Non-edible Substances and Food Additives that may be added illegally in food. In the list, melamine, industrial sulfur, Sudan red, sodium formaldehyde sulfoxylate, waste edible oil, malachite green, hair water and fluorescent whitening substances are classified as non-edible substances but not food additives.