Agricultural contaminants, environmental contaminants and adulterants, these can be considered as the three main sources of food contaminants. The agricultural contaminants include pesticides and veterinary drugs. Environmental contaminants are those chemicals transferred to food during growing, processing, packaging, storage or distribution; these include heavy metals, mycotoxins, histamine and chemical toxins. Adulterants are substances intentionally added to foodstuffs that are either harmful to the consumer, illegal present or constitute food fraud.