a chemical which, at a required temperature and pressure, can exist in the gaseous state in sufficient concentration to be lethal to a given pest organism. This definition implies that a fumigant acts as a gas in the strictest sense of the word.
Dried aromatic herbs, spices and vegetable seasonings are frequently contaminated and/or infested with organisms and their metabolites which are harmful to public health. Such contamination and/or infestation can no longer be treated with fumigants such as ethylene oxide because of the toxic potential of their residues.