Newport Beach-based Amvac volunteered to cancel some uses and add restrictions to others for a pesticide known as DDVP, which is commonly used to kill mosquitoes, fleas and other insects in households and businesses, the EPA said.
Amvac acted after EPA officials provided the firm with the results of an ongoing health assessment that raised questions about the risks associated with exposure to the chemical, which is related to World War II era nerve agents.
DDVP is listed by California as a known carcinogen and is part of a class of chemicals that has been linked to developmental damage in children. Exposure to DDVP can cause flu-like symptoms, including headaches, nausea and vomiting. In large doses, the chemical is fatal.
"If these changes [in usage] do occur, these products can be used safely," said James Jones, EPA's director of Office of Pesticide Programs.
Environmental groups, which consider DDVP one of the most dangerous pesticides on the market, said that the proposed restrictions do not go far enough. They noted that the EPA previously considered banning most residential uses of DDVP, and accused agency officials of "illegal" meetings with Amvac that did not allow adequate public participation.
"All of these uses inside the home are dangerous things. That's what is of most concern," said Aaron Colangelo, an attorney with the Natural Resources Defense Council. "They're allowing them to stay on the market."
There was no immediate coment from Amvac.
DDVP is used in numerous products, including pet collars, pest strips and aerosol sprays. It is sold under a number of names, including Alco No-Pest Strip, Amvac Insect Strip, and Swat Pest Strip.
The chemical has both residential and commercial uses, mostly in niche areas such as the fumigation of food storage areas for peanuts and pistachios, and mushroom farms.
Under Amvac's proposal, consumers will continue to be able to purchase pest strips, which release minute quantities of DDVP for months, killing insects by attacking the nervous system.
The size of some strips will be reduced. Labels will be modified to warn that larger strips should not be used in homes, except in garages, attics and crawl spaces occupied for less than 4 hours per day. Smaller strips will be limited for use in closets and cupboards, so long as children or the elderly are not present.
In addition, Amvac will cancel DDVP products used as home foggers, on the lawn and for treating cracks and crevices.
Once the EPA finalizes the proposal in coming months, the products will be allowed to remain on the shelves of stores for another 18 months. Jones said the EPA did not believe there was an immediate threat from using the products.
"We don't think people will be exposed in a way that will cause harm," Jones said.
DDVP has a long and contentious regulatory history. The EPA raised concerns about it as far back as 1982, and it has been undergoing a special safety review since 1988.
Amvac officials have fiercely defended the safety of their product, saying that DDVP has caused no long term damage to humans and that the product plays an important public health role in killing disease-carrying pests.
The company was at the center of a controversy in the late 1990s when it proposed demonstrating the safety of its product by testing human, rather than animal, subjects. Environmental groups raised ethical concerns over the tests.
After a drawn-out court battle, the EPA finalized a rule this year allowing limited consideration of human test data. Last month, the EPA's Human Studies Review Board delivered a mixed verdict for DDVP, saying that the tests allowed the EPA to loosen safety standards for short and medium term exposure, but not for chronic exposure, which is possible with pest strips, which remain potent for up to four months.