Methyl Iodide to Be Registered by DPR

Date:05-26-2010


Department of Pesticide Regulation Director Mary-Ann Warmerdam has proposed registration of methyl iodide with a comprehensive set of use restrictions that are much more stringent than those required by the federal government. Methyl iodide products are made by Arysta LifeScience Corp. and sold under the brand name, Midas. The comment period is extended to June 29, 2010.

The U.S. EPA registered methyl iodide in 2007 as a replacement for methyl bromide, which causes damage to ozone in the upper atmosphere. Methyl iodide does not harm the ozone layer.

The major uses of methyl bromide in California are to treat soil where strawberries, nursery plants and nut trees are to be planted. Since U.S. EPA considers methyl iodide a feasible alternative to methyl bromide, the federal agency is expected to approve far fewer exemptions for methyl bromide in California.

"By law, we cannot register a pesticide unless it can be used safely," says DPR Director Mary-Ann Warmerdam. "After extensive reviews, we have determined methyl iodide can be used safely - with the extra, health-protective use restrictions we are proposing that are much stricter than those imposed anywhere else in the U.S. My department considered a wide range of scientific input and followed protocols of both U.S. EPA and the World Health Organization to develop use restrictions to prevent potentially unsafe exposures."

DPRs proposed methyl iodide registration takes a much more health-protective stance than U.S. EPA. For example, Californias allowable exposure of 96 parts per billion (ppb) for licensed professionals who apply or handle methyl iodide will be half of what U.S. EPA allows. For others (those not handling or using methyl iodide), DPR will not allow exposures above 32 ppb averaged over 24 hours. This level is five times lower than the U.S. EPA level.

Restrictions include:

* Larger buffer zones around all applications.
* A minimum of a half-mile buffer around schools, hospitals, nursing homes and similar sites. 
* Reduced application rates and acreage that can be treated. 
* Application limits to protect groundwater.

DPR also will make methyl iodide a California-restricted material, meaning users will be required to have special training and a permit from the county agricultural commissioner, who can impose added use controls tailored to the application site.

Methyl iodide, also called iodomethane, is licensed for use in 47 other states. Injected into soil before crops are planted, the fumigant spreads through the soil to kill insects, weed seeds, plant diseases and nematodes. It can be applied by drip irrigation under a special protective tarp or injected into the soil using a tractor that automatically places a tarp over the ground after application.

DPRs proposed decision to register methyl iodide products is posted at www.cdpr.ca.gov, click on "Decisions Pending" link.