Methyl Iodide - Use As A Pesticide

Use As A Pesticide

Methyl iodide had also been proposed for use as a fungicide, herbicide, insecticide, nematicide, and as a soil disinfectant, replacing methyl bromide (also known as bromomethane) (banned under the Montreal Protocol). Manufactured by Arysta LifeScience and sold under the brand name MIDAS, methyl iodide is registered as a pesticide in the U.S., Mexico, Morocco, Japan, Turkey, and New Zealand and registration is pending in Australia, Guatemala, Costa Rica, Chile, Egypt, Israel, South Africa and other countries. The first commercial applications of MIDAS soil fumigant in California began in Fresno County, in May, 2011.

The use of methyl iodide as a fumigant has drawn concern. For example, 54 chemists and physicians contacted the U.S. EPA in a letter, saying "We are skeptical of U.S. EPA’s conclusion that the high levels of exposure to methyl iodide that are likely to result from broadcast applications are “acceptable” risks. U.S. EPA has made many assumptions about toxicology and exposure in the risk assessment that have not been examined by independent scientific peer reviewers for adequacy or accuracy. Additionally, none of U.S. EPA’s calculations account for the extra vulnerability of the unborn fetus and children to toxic insults." EPA Assistant Administrator Jim Gulliford replied saying, "We are confident that by conducting such a rigorous analysis and developing highly restrictive provisions governing its use, there will be no risks of concern," and in October the EPA approved the use of methyl iodide as a soil fumigant in the United States.

The California Department of Pesticide Regulation (DPR) concluded that methyl iodide is "highly toxic," that "any anticipated scenario for the agricultural or structural fumigation use of this agent would result in exposures to a large number of the public and thus would have a significant adverse impact on the public health", and that adequate control of the chemical in these circumstances would be "difficult, if not impossible." Methyl iodide was approved as a pesticide in California that December. A lawsuit was filed on January 5, 2011, challenging California's approval of methyl iodide. Subsequently, the manufacturer withdrew the fumigant and requested that California Department of Pesticide Regulation cancel its California registration, citing its lack of market viability.