"Alternate Gas Fumigants"

Fumigants have been used worldwide for many years. To be effective, fumigation should be carried out in gastight storage. The standard of gastightness is consistent with a decay of an excess external pressure from 500 Pa to 250 Pa in not less than 5 minutes in filled storage (SCA Technical Report 1980). Because of their volatility, fumigants dissipate from foodstuffs upon exposure to the open air with minimal chemical residues. However, after ventilation there is no ongoing protection from insect re-infestation. The currently preferred fumigants are methyl bromide (liquefied gas) and phosphine (generated from solid phosphide which reacts with atmospheric moisture or liquefied gas). ECO2FUME (2 wt % PH3/CO2) a non-flammable gaseous phosphine fumigant was developed by BOC (Ryan and Latif, 1989) to eliminate phosphine's flammability hazard [LEL = 1.6%]. ECO2FUME has been patented (British Patent 2177004, US Patent 4.889,708) and is globally marketed by CYTEC Industries Inc. ECO2FUME will treat in excess of 12,000,000 tonne of grain in 2001 and most is used b