The Science

Methyl iodide, is a fumigant pesticide used primarily on strawberries. It is manufactured and promoted primarily by Arysta LifeScience, the largest private chemical company in the world.
Also known as iodomethane, methyl iodide was proposed for agricultural use as an alternative to methyl bromide, which has been phased-out under the Montreal Protocol because it is depletes the ozone layer. Arysta LifeScience is using this phase-out as a political opportunity to push methyl iodide as a drop-in replacement that will be very expensive for farmers as well as public health.
The science on methyl iodide's public health impacts is so clear that leading chemists and doctors are taking a stand against it's use in agriculture. Their verdict? methyl iodide causes cancer, late term spontaneous miscarriages and is a neurotoxin. It has no place in agriculture.
Scientists are "Astonished"
The U.S. Environmental Protection Agency (EPA) first proposed the registration of methyl iodide as a pesticide in 2007. Scientists from around the country who use this chemical in their labs were shocked, and responded with a forceful letter from more than 50 scientists, including five Nobel laureates stating,
It is astonishing then that the Office of Pesticide Programs is working to legalize broadcast releases of one of the more toxic chemicals used in manufacturing into the environment.
National approval was granted at the end of the Bush administration despite these objections. Then, in 2010, it was the California Department of Pesticide Regulation’s (DPR) turn to investigate possible registration.
As California grows upwards of 85% of the nation's strawberries, DPR established an independent scientific review committee composed of some of the best scientists in the nation. The findings of the Scientific Review Committee are clear: “any anticipated scenario for the agricultural...use of the agent would...have a significant adverse effect on the public health” saying methyl iodide would be, “difficult, if not impossible to control.” Committee chair, Dr. John Froines, called methyl iodide,“one of the most toxic chemicals on earth.”
History repeated itself as scientific evidence was once again ignored. In the final days of the Schwarzenegger administration, California agreed to open its strawberry fields to this new cancer-causing pesticide.
Our Health and Environment

Credit: Lauren Sommer, KQED; Adrienne Wollman, NPR
Scientists using this chemical in the lab to induce cancer in cells take serious precautions — using a ventilation hood and protective gear when handling small amounts. If approved for agricultural use, methyl iodide would be applied, as a gas, at rates of up to 100 lbs per acre. In addition to the threat posed to farmworkers and communities living next to strawberry fields, methyl iodide would likely contaminate groundwater.
Humans exposed to methyl iodide experience dizziness, sleepiness, nausea, diarrhea, slurred speech, lack of coordination, muscle convulsions — and in some cases, pulmonary edema. Listed as an EPA Hazardous Air Pollutant, methyl iodide also affects the the lungs, liver, and kidneys.
- Cancer: Known to cause thyroid and lung tumors, methyl iodide is on the California Proposition 65 list of carcinogens. The fumigant's mutagenic properties reaffirm its cancer-causing potential.
- Developmental & Reproductive Toxicity: In addition to increasing the risk of miscarriage, methyl iodide compromises healthy development of fetal organs including the heart, liver, and brain -- causing permanent damage. (See: CDPR's Assessment)
- Neurotoxiciy: Methyl iodide is a potent neurotoxin — four times more toxic than methyl bromide. Both chronic and acute exposure to methyl iodide can cause permanent damage to the central nervous system.
- Thyroid Toxicity: Methyl iodide is toxic to the thyroid gland and interferes in thyroid hormone levels. Research shows that when methyl iodide compromises these hormones during critical windows of fetal development, exposure can increase risk of miscarriage.
Safe Alternatives
Strawberries can be grown without methyl iodide or other toxic pesticides. Innovative farms large and small are already successfully delivering on this commitment.
Farming without Methyl Bromide
Strawberry production in California has been consistently growing since the 1970’s, without this chemical on the market. Meanwhile, methyl bromide use in the United States has decreased 90% since 1995, dropping from 25,500 metric tons in the early 1990s to 2,200 metric tons in 2009. California farmers have innovated and kept their yields high - and growing – without methyl bromide. “Over 50% of California strawberries are now produced without the use of methyl bromide and that percent likely will increase yearly,” according to the EPA.
Organic strawberries in California
Organic strawberry production has a superior economic profile than conventional production, generating $41,250 in revenue per acre of organic strawberry production and $14,908 profit per acre. With price premiums that range from 40% to 176%, California farmers would therefore benefit from organic production [United States Department of Agriculture, Economic Research Service.].
Real Life Examples in Santa Cruz, CA
Organic strawberry farmer Jim Cochran has been growing strawberries in the central coast of California for nearly thirty years. He does not use dangerous pesticides like cancer-causing methyl iodide or ozone depleting methyl bromide. Instead he uses agroecological methods of pest management. -- http://www.swantonberryfarm.com/
Swanton Berry farm strawberries are seasonally available at New Leaf Community Markets, one of the first retailers to sign our Safe Strawberry pledge.




