Decontamination of food itself will be attempted only in emergency situations when there is no alternative supply of food. Frying, roasting or boiling will not remove traces of nerve or blister agents from meats. In general, salvage of foods contaminated with droplets of the blister agents, especially the arsenical blister agents, is not practical. Contamination of water may lead to a toxic hazard when it is used for drinking, washing, and food preparation. Although many agents hydrolyse in water, this is not satisfactory as a method of decontamination.
Arsenical agents leave degradation products which are toxic even when hydrolysis is complete.
The appearance of water does not indicate contamination, and any water exposed to high concentrations of vapour, or any liquid contamination must be regarded as toxic until tests have been made. Water from deep wells will be safe provided that the well mouth is covered. Water in closed metal tanks will be safe provided that the tap and air inlet are decontaminated. Table 12-III gives the maximum allowable concentrations for certain agents in accordance with Stanag 2136. Water with a pH less than 3 is condemned since this high acidity may be due to contamination with mustard, but if free chlorine is present throughout 30 minutes mustard will be destroyed.