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California Environmental Protection Agency

Department of Pesticide Regulation

Release No. 94-24
Date: June 30, 1994

Media Contact:
Veda Federighi
(916) 445-3974


SACRAMENTO -- Cal/EPA's Department of Pesticide Regulation expressed support today for the proposed voluntary cancellation of the pesticide mevinphos by its manufacturer. At the same time, DPR also imposed strict restrictions on use of the chemical for the next eight months, until cancellation is complete.

"If the registrant had not voluntarily withdrawn from the market, both DPR and the U.S. Environmental Protection Agency would have taken regulatory action," said DPR Director James W. Wells. "We are pleased that the manufacturer has helped us avoid the costly and potentially lengthy legal proceedings involved in a cancellation action. These proceedings could have well dragged out into next year. During that period, the registrant would have been free to continue to manufacture and sell mevinphos."

Under the terms of the proposed cancellation agreement between Amvac Chemical Corp. and USEPA, mevinphos use will be allowed only through February 1995 to use up existing stocks. In California during that interim period, DPR and the county agricultural commissioners are imposing additional safety measures, over and above the highly restrictive use requirements already in place, said Wells. These precautionary measures will provide added protection to workers.

"We support this voluntary decision by the manufacturer to cancel the registration of mevinphos," said Wells. "Over the past several weeks, we have been working closely with USEPA on this issue, sharing data and evaluations. As a result, both agencies concluded that even when properly used, mevinphos is detrimental to the public health and safety of agricultural workers, and its registration should be cancelled.

"This kind of cooperative effort is part of a wide- ranging program of harmonization that DPR and USEPA began last year to cut through unnecessary bureaucratic obstacles without in any way compromising California's tough environmental standards," said Wells.

"A key goal was to encourage the use of safer pest control methods," said Wells. "This process has worked as we hoped it would, helping to remove from the market a chemical which, although still useful to agriculture, was found to present an unacceptable risk to workers over the long term."

Today, USEPA announced that Amvac has proposed a voluntary cancellation of all uses. Under the proposed agreement, Amvac will agree to immediately stop production of mevinphos products for sale and distribution in the U.S. Existing stocks can be sold through December 1994, when Amvac must recall all unsold product. After February 1995, all mevinphos use must end.

Until mevinphos use ends, DPR and the county agricultural commissioners are placing new restrictions on the chemical. Among the new requirements are that applications be made only after a farmer receives a written "prescription" from a DPR-licensed pest control advisor, and that applications be made only by a DPR-licensed pest control business. Aerial applications are also prohibited within a half-mile of field workers, and this buffer zone must remain monitored throughout the application.

"We expect the stringent interim conditions to reduce risk to workers significantly," said Wells. "In addition, the restrictions are so demanding that we believe that farmers will go to alternatives where they are available, greatly reducing mevinphos use."

Mevinphos, also known by the trade name, Phosdrin, is a broad-spectrum organophosphate insecticide. It is used to control aphids, leaf miners, mites, grasshoppers, caterpillars, and many other insects. It can be used on 48 food and nonfood crops in California.

Total reported mevinphos use in California in 1992 was 228,290 pounds, 294,441 pounds in 1991, and 333,793 pounds in 1990. During these three years, more than 60 percent was used on head and leaf lettuce and broccoli. Substantial amounts were also used on celery, grapes, and cauliflower. Mevinphos is used only in production agriculture.

Because of its toxicity, mevinphos has been a restricted-use pesticide for many years. Restricted-use products may be possessed and used only by persons who have demonstrated knowledge on safe use and handling of the product, and who have obtained a permit for use from the county agricultural commissioner.

Effective immediately, county agricultural commissioners will cancel existing mevinphos permits for some uses and place additional restrictions on others. Permits will be cancelled for mevinphos use in greenhouses and on tree crops and grapes. These crops involve particularly high contact by workers with mevinphos-treated foliage. For other crops, the commissioners will place new conditions on existing permits to mandate certain precautionary use practices until February 28, 1995, when use will end.

These conditions include:
  1. Applications can be made only by a licensed pest control business. (Previously, farmers or their employees who had received county certification could also apply mevinphos.) A written recommendation by a licensed pest control advisor is required.
  2. Aerial applications are prohibited within a half-mile of field workers. A person with authority to stop the operation must be present to monitor the buffer zone.
  3. The use of hand-held application equipment and air- blast sprayers also is prohibited.
  4. Tank mixes combining mevinphos with other cholinesterase-inhibiting pesticides are prohibited.
  5. Persons using mevinphos will be required to participate in a medical monitoring program, which includes cholinesterase blood tests for signs of mevinphos exposure every 30 days or more often if ordered by the supervising physician.
  6. The only applications allowed are those between 2 and 14 days before harvest. This ensures that only the most critically needed late-season uses are allowed. (As a result of recent federal regulations, some mevinphos product labels now have a 72-hour minimum between application and when workers may reenter fields. In those cases, the mevinphos applications can occur no later than 3 days before harvest.)

Mevinphos can be used close to harvest because it breaks down rapidly. The major use of mevinphos for which no alternative is currently available is for insect and worm control on certain crops just before harvest. For example, aphid populations can flare up dramatically at any point in the growing season. If an infestation occurs close to harvest, growers use mevinphos because it is effective and dissipates rapidly. Quality standards imposed by packers, processors, and other buyers--ultimately standards imposed by consumers reluctant to purchase fruits and vegetables with insects or insect damage--make it critical for growers to control insects just before harvest.