Formaldehyde and hexamethylenetetramine as food additives: chemical interactions and toxicology.

Formaldehyde (FA) and hexamethylenetetramine (HMT) are used in cheese production to control gas-forming clostridia; FA also occurs naturally in some foods at levels of 1-20 mg/kg. The toxicology of FA and HMT are briefly discussed together with their reaction in foods. The most abundant end-product of FA in cheese is spinacine derived from the N-terminal histidine residue in gamma 2-casein. Acute and short term toxicological studies on spinacine enable a No Observed Effect Level of 300 mg/kg body weight/day to be determined, leading to an Acceptable Daily Intake (ADI) for man of 3 mg/kg body weight/day. From these data a Tolerance Level (TL) of 1800 mg spinacine/kg cheese can be derived, leading to a Safety Margin (SM) of 12.9. It is concluded that there is no appreciable health risk from consumption of cheese made using formaldehyde (Grana Padano) or hexamethylenetetramine (Provolone).