According to the Montreal Protocol, methyl bromide (MeBr) is a volatile chemical that depletes the ozone layer and is planned for eventual phased out. MeBr is a vital tool in pre-plant pest and weed control and its loss would be detrimental to farmers if a viable substitute cannot be found. This research explores the fate of potential MeBr substitutes such as Vapam (metam-sodium) and K-pam (metam potassium). The objective of these studies is to evaluate the volatilization rates of K-pam and Vapam in different soil types and with varying organic matter levels in effort to minimize the volatilization loss of these chemicals. In one study K-pam and Vapam were injected into six columns filled with sandy soil and chemical volatilization was measured over time. A similar study was performed using a sandy clay loam soil. Volatilization of Vapam and K-pam's breakdown product, methyl isothiocyanate (MITC) was found to be similar for both chemicals. This same sandy clay loam soil was used in a third study where K-pam was injected into soils containing 4.3, 5.3, and 7.3 % organic matter. Volatilization of MITC was monitored in columns that were prepared to simulate two possible field conditions; one with organic matter evenly dispersed throughout the soil depth, and the other with organic matter in the upper 15 cm of soil (plow layer).