Trichlorfon Pesticide Risks And Regulatory Decisions.pdf

EPA has assessed the risks of trichlorfon and reached a decision presented in the "Report on FQPA Tolerance Reassessment Progress and Interim Risk Management Decision for Trichlorfon". With the risk mitigation measures required, trichlorfon fits within its own "risk cup"; its individual, aggregate risks are within acceptable levels. EPA's next step under the Food Quality Protection Act (FQPA) is to consider the cumulative risks of all the OP pesticides, which share a common mechanism of toxicity. The interim decision on trichlorfon cannot be considered final until these cumulative risks are considered. Further risk mitigation may be required at that time.

Trichlorfon is used as an insecticide on golf course turf, home lawns, non-food contact areas of food and meat processing plants, ornamental shrubs and plants, and ornamental and bait fish ponds to control insects such as lepidopteran larvae, white grubs, mole crickets, cattle lice, and others. Average domestic usage of trichlorfon is about one million pounds active ingredient (a.i.) per year, mainly allocated to lawn care operators (74%) and golf courses (18%).

Trichlorfon can cause cholinesterase inhibition in humans, leading to overstimulation of the nervous system, nausea, dizziness, confusion, and at very high exposures, respiratory paralysis and death. Dietary risks from food alone for both acute and chronic exposure are not of concern to the Agency. However, when surface water is considered as the source of drinking water, dietary risks (food and water) exceed the Agency's level of concern for children 1 - 6 years.

The current occupational risk assessment indicates risk concerns for pond applicators, applicators using broadcast treatment to golf course fairways, and postapplication worker concerns following foliar treatments of ornamentals. However, the Agency believes that required mitigation will effectively reduce exposure and risk to a level that is not of concern to the Agency.

To mitigate risks to handlers and workers, EPA requires:

Prohibit broadcast treatment to golf course fairways; spot treatment to fairways is permitted.
Require 7-day application interval for application to turf, and limit applications to no more than 3 per calendar year.
Require applicators to use a truck-drawn spray rig for ornamental fish and bait ponds over 1 acre.
Prohibit foliar application to ornamentals; allow only direct soil spray application to base of plant.

EPA is encouraging the public to participate in the review of the OP pesticides through a six-phased pilot public participation process. The Agency is exchanging information with stakeholders and the public about the OPs, their uses, and risks through Technical Briefings, stakeholder meetings, and other fora.

Numerous opportunities for public comment were offered as this decision was being developed. The trichlorfon TRED is issued in final, without a formal public comment period. The docket remains open, however, and any comments submitted in the future will be placed in this public docket. When EPA has considered the cumulative risks for of the OP pesticides, the Agency will issue its final tolerance reassessment decision for trichlorfon and may require further risk mitigation measures.