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Media Contact: Lea Brooks
July 29, 2009 (09-09)

Methyl Iodide Risk Assessment Will Undergo External Review

SACRAMENTO – The Department of Pesticide Regulation’s draft risk assessment for the fumigant methyl iodide will undergo an external peer review as planned, DPR Director Mary-Ann Warmerdam announced today. The intent of a risk assessment is to determine potential risks to human health and the environment and the circumstances under which a product can be used if it is registered.

"Although an external peer review is not required by law, we want to confirm that our draft risk assessment of methyl iodide is based on sound science," she said. "The risk assessment will serve as the basis for our decision on whether methyl iodide should be registered in California."

Because of budget uncertainties, there had been concern that various projects might have to be delayed. With resolution of the budget, DPR is continuing to move forward with the external peer review process.

Following standard procedure, DPR’s draft methyl iodide risk assessment has already undergone peer review by the Office of Environmental Health Hazard Assessment, also part of the California Environmental Protection Agency, and the U.S. Environmental Protection Agency (U.S. EPA). DPR is reviewing the comments received and will revise the document as appropriate before the external review begins.

The external review will be spearheaded by John Froines, Ph.D., director of the Center for Occupational and Environmental Health at the University of California, Los Angeles. He has convened a panel of eight nationally and internationally renowned experts in various scientific fields to evaluate DPR’s risk assessment of methyl iodide.

The panel will hold a workshop Sept. 24-25 that will be open to the public at a Sacramento location to be announced. The first day will be devoted to presentations by state scientists. The second day will provide opportunity for public comments.

Methyl iodide is among replacements being considered for methyl bromide, another fumigant. Methyl bromide is being phased out as part of the Montreal Protocol, an international treaty initially signed in 1987 to protect the ozone layer. Methyl iodide has been registered by U.S. EPA and is being used in other states.

Pesticides must be registered by DPR before they can be sold or used in California. "DPR will not register any pesticide unless we can determine it can be used safely," Warmerdam said.

This process includes scientific evaluation of the hazards of pesticides to ensure they can be used safely without harming people and the environment. On occasion, DPR chooses to conduct a full risk assessment of a new active ingredient before registration - this was the case with methyl iodide.

For additional information about the risk assessment process, please review this fact sheet on DPR’s Web site at:

One of six departments and boards within the California Environmental Protection Agency, DPR regulates the registration, sale and use of pesticides to protect people and the environment. Additional information about DPR is posted at