Linuron

Dear Ms. St. Clair: The following comments on the Preliminary Ecological and Human Health Risk Assessments for Linuron are offered on behalf of the National Potato Council (NPC). NPC represents potato growers who produce more than ninety-five percent of the potatoes grown in the United States. That potato production is valued at nearly $4 billion dollars at farm gate. Production costs for potatoes range from $3500 to more than $4000 an acre. Reduced yields or crop losses due to the impacts of pests and weeds can result in serious economic losses to growers and increase the cost of potatoes to consumers. Access to herbicides that are effective in managing weeds is critical to maintaining potato yields. Linuron has proven to be a safe, effective herbicide that meets the needs of potato growers in all the major growing areas. The development of resistance to herbicides is a growing concern for potato growers. Growers actively rotate classes of herbicides to prevent the development of resistance. Linuron is an important herbicide used by potato growers as a part of their resistance management programs. Based on a review of the Preliminary Risk Assessment documents, it seems clear that EPA has determined broadly that the existing data and available studies support the continued registration of Linuron. Based on their history of safe use of this product, potato growers also support that conclusion. The Health Risk Assessment for Linuron, like some other risk assessments conducted by the Agency, relies too heavily on water modeling at the expense of using actual monitoring data. Water modeling is valuable when there is no access to actual monitoring data. We suggest that when actual monitoring data is available risk assessments should be based predominately on that data. We would encourage the Agency to consider comments submitted by the registrant that offer opportunities to improve the Risk Assessments. In particular, the Agency should thoughtfully consider refinements to aquatic exposure modeling, the estimation of residues related to chronic exposure for birds and mammals, the need for additional fish chronic toxicity data, additional studies on toxicity to pollinators and the need for an additional 10X FQPA safety factor. On behalf of U.S. potato growers, we appreciate the opportunity to participate in the registration review process for Linuron. We support science-based decision making for pesticides and are committed to working with EPA to reach sound regulatory decisions. We are glad to provide any information that the Agency might require on product use patterns or other information on Linuron use that might inform your decision making. Sincerely, John Keeling Executive Vice President and CEO National Potato Council