The canister cannot be used on a respirator after being used for this purpose. On a larger scale, a modified water purification unit in which the kieselguhr filter is supplemented by a bed of activated charcoal is under development. Small amounts of water, in units of one litre, may be superchlorinated. Simple chlorination, as is used to disinfect water from naturally occurring bacterial contaminants, is not sufficient to decontaminate water suspected of being contaminated with chemical agents. Larger quantities of water may be treated by flocculation with metal salts, after which the water is treated with chlorine.
Reverse osmosis is an effective method of removing contamination, including heavy metals.