Abstract
Ethyl formate is an old liquid fumigant that has a boiling point of 54°C and vaporizes readily at normal temperatures. It occurs naturally in soil, water, vegetation, animal products, and a range of raw and processed foods. Therefore, ethyl formate is generally recognized as safe (GRAS) as a food additive and is used as a flavoring agent with no evidence that it is hazardous to the public. The work safety-related threshold limit value (TLV) is 100 ppm, which is the concentration that a worker can be exposed to day after day for a working lifetime without adverse health effects. Ethyl formate has a long history as a fumigant for stored products in general cargo, packaged foods, and dried fruits, in particular. Its vapor has been shown to be toxic to stored-product insects and has been used successfully to eliminate a broad range of insect pests without leaving poisonous residues. Ethyl formate was reevaluated for grain protection in the 1980s and has been useful as a rapid fumigant for grains and similar durable commodities. However, the concentration of ethyl formate required to control internal developmental stages of insects is higher than the lowest explosive limit (LEL). It is therefore necessary to reduce the flammability by mixing ethyl formate with an inert gas. Unlike most other fumigants, ethyl formate kills insects rapidly, and it breaks down to two naturally occurring products: formic acid and ethanol. Therefore, ethyl formate has great potential as an alternative fumigant for methyl bromide quarantine fumigation and management of phosphine resistance.