State agency resumes review of fumigant


Facing accusations that they were fast tracking approval of a known carcinogen, state pesticide regulators have resumed a review of the fumigant methyl iodide for use on strawberry fields.

A peer review of methyl iodide had been suspended during the state budget crisis, prompting concern from legislators and environmentalists that the agency and the governor were bowing to industry pressure to approve the chemical as a substitute for the banned fumigant methyl bromide.

In a letter sent last Monday to Gov. Arnold Schwarzenegger and the state Department of Pesticide Regulation, 27 state legislators urged state officials to look more closely at the risks of methyl iodide, a compound listed under a provision of 1986’s Proposition 65 as a carcinogen.


Laboratory tests on animals have linked methyl iodide to miscarriages, cognitive impairment and thyroid toxicity.

“We were surprised to learn that your administration has begun to explore the possibility of ‘fast tracking’ the approval of methyl iodide through an abbreviated process that could make it available for use as early as this fall,” wrote Assemblyman Bill Monning (D-Carmel) and state Sen. Mark Leno (D-San Francisco) in the letter.

On Wednesday, the Department of Pesticide Regulation announced plans to resume a peer review and denied that any plan had been afoot to fast track the chemical. It also announced plans for a public hearing in September.

Methyl iodide, manufactured by Tokyo-based Arysta LifeScience Corp. under the brand name Midas, would provide a replacement for methyl bromide, an ozone-depleting fumigant that is being phased out through an international agreement.

“Growers are anxious for a replacement for methyl bromide, but DPR is committed to following the scientific process before making a decision on the registration of methyl iodide,” said a representative of the Department of Pesticide Regulation in an e-mail.

Monning said he was encouraged by the state’s “apparent change of course.”

The chemical has been approved for use in every state except California, Washington and New York, and the chemical industry has been closely watching developments in Sacramento.


The Environmental Protection Agency in 2007 approved the use of methyl iodide for one year and extended its registration in 2009, despite risks such as thyroid cancer that the agency identified in its own study.

“The exposures that we would expect would be well below anything that we would see in a laboratory study where that effect was produced,” EPA scientist Lois Rossi said in a telephone interview.

The approval came despite a letter from more than 50 scientists, including five Nobel laureates, calling methyl iodide “one of the most toxic chemicals used in manufacturing.”

“As chemists and physicians familiar with the effects of this chemical, we are concerned that pregnant women and the fetus, children, the elderly, farmworkers and other people living near application sites would be at serious risk if methyl iodide is permitted for use in agriculture,” the letter stated.

Federal law requires growers to set up buffer zones and prohibits workers from entering the field for 48 hours after methyl iodide is applied.

But critics said such precautions don’t always protect people living or working near the plots, as evidenced in the 1999 metam sodium drift that sickened dozens in Earlimart, Calif., north of Bakersfield.


“There’s a gap between warning labels and what happens in the real world,” Monning said. “We have to balance crop yields versus human health and safety.”