Tolerance Reassessment Advisory Committee

Note: This information is provided for reference purposes only. Although the information provided here was accurate and current when first created, it is now outdated.

TRAC 5/27/98

Staff Background Paper # 5.1

Summary of Organophosphate Pesticide Usage

Number of OPs: Of the 39 registered organophosphate pesticides, 37 are insecticides and 2 (bensulide and tribufos) are herbicides. There are an additional 8 OPs that have been canceled, but still have tolerances on the books (import tolerances).

OPs Relative to All Pesticides: Organophosphate pesticides account for 8% of the total pesticide use in the U.S. (in terms of pounds of active ingredient)

OPs Relative to Other Insecticides: Organophosphate insecticides account for approximately 50% of the total insecticide-treated acres in the U.S. and about 65% of the pounds of insecticide active ingredient applied to agricultural settings.

OP Agricultural Usage: 60 million lbs. of OPs are applied to 38 million acres of agricultural crops in the U.S. annually (about 10% of the total area of agricultural crops in the U.S.). Each acre is treated an average of 1.6 times. The agricultural use sites are as follows:

million lbs. applied

field corn 19

cotton 15

other field crops 10

fruits and nuts 9

vegetables 7

OP Non-Agricultural Usage: 17 million pounds are applied to non-agricultural sites:

million lbs. applied

termiticide applications 4

livestock and pets 4

mosquito control & noncrop 3

residential & commercial indoor 3

grain storage facilities 2

turf and ornamental 1

Most Used OPs: 5 OPs (chlorpyrifos, terbufos, profenofos, tribufos, and malathion) account for 60% of all OPs applied (lbs of active ingredient basis).

OP Tolerances: OP tolerances account for 14% of the total number of tolerances established.

Residential Use: 17 OPs are registered for residential uses (applied in or around residential settings, including home pest control, lawns, gardens, and mosquito control), accounting for approximately 10% of the OPs used annually, or a total of almost 8 million pounds.

Public Health Use: 22 OPs are registered for public health uses (e.g., mosquito control and control of other disease-spreading pests).

Why OPs? OPs are popular because they: are inexpensive, have broad-spectrum pest control, are registered on many crops, are very effective, and generally have not developed resistance problems.