Fumigant

1. A liquid or solid substance that forms vapors which destroy pathogens, insects, etc. Fumigants are usually used in soils or closed structures such as under a tent.


This is a field covered with plastic tarp for 24-48 hours after fumigation to prevent the escape of volatile chemiclas.
Source:http://www.apsnet.org/education/IllustratedGlossary/PhotosE-H/fumigant.htm