Below is page 1 of the article "The Trouble with Carbaryl" by Warren Schultz Jr., from the October 1984 issue of Organic Gardening magazine. It outlines the history of carbaryl in the United States, at least up to 1984.
Carbaryl may be America's most popular pesticide. Commonly sold under the trade name Sevin, 25 million pounds of it are used annually. If you hunt through basements and garages across the country, you'll find carbaryl in over 5 million households. It's in over 1.500 products and used on over 100 crops to control more than 500 insect pests. It's been sprayed over hundreds of thousands of acres to battle gypsy moth, dusted on cats and dogs to control fleas, and used in gardens to kill Colorado potato beetles and flea beetles. Because it's a broad-spectrum insecticide, Sevin is also extremely toxic to honeybees and many beneficial insects.
Carbaryl is a contact nerve toxin. It works by inhibiting cholinesterase, an enzyme found in insects and mammals. The result is a disruption of nerve-impulse transmissions. If the dosage is high enough, it shuts down bodily function.
The pesticide was first introduced to the U.S. by Union Carbide in 1956, and that company is still the exclusive manufacturer here. In its literature the company proudly states that "almost every person in the U.S. A. has come into contact with either the chemical itself or with the products of its degradation." That's a major reason - widespread use - why carbaryl may be one of America's most dangerous pesticides.
You wouldn't know it from reading the label. The recommendations and precautionary statements make Sevin sound about as safe as baby powder. Inspect a canister or bottle of Sevin at the local hardware store, and you won't find the words "Poison" or even "Danger" anywhere on the package.
But Clinical Toxicology of Commercial Products gives carbaryl a rating of 4 on a scale of 1 to 6 with the highest number being the most toxic. Recent studies, though, suggest that the long-term effects of carbaryl exposure may be more hazardous than the acute toxicity. In fact, as long ago as 1969, a U.S. Department of Health, Education and Welfare report recommended that the use of carbaryl "should be immediately restricted to prevent risk of human exposure." The reason? Studies showing carbaryl could cause birth defects in mammals. So far, the HEW warning has been ignored.
In the mid-1970's the Environmental Protection Agency, which registers pesticides, decided to rethink its position on carbaryl. The pesticide was made a candidate for the Rebuttable Presumption Against Registration procedure. Under the RPAR process, when questions arise about the risks of a certain pesticide, the public is permitted to submit evidence to make a case against its registration The pesticide manufacturers then have an opportunity to rebut the evidence. If they can, the pesticide is returned to registration. If they can't the pesticide is either restricted, taken off the market, or changes are made in allowed uses and labeling.
Carbaryl was on the road to RPAR when it was abruptly withdrawn from the process in 1980. Never before had a pesticide candidate gone that far into the process without being taken all the way through the RPAR proceedings. Despite the fact that working groups from the EPA's Office of Pesticide Protection twice recommended that carbaryl be taken through RPAR, and despite several scientific studies that raised serious health questions, the director of the EPA's Office of Pesticide Programs decided that there was not enough evidence. Instead, the EPA elected to conduct a review outside of the RPAR process.
Now, 4 years later [1984], the EPA has requested two scientific studies and made a few minor label changes for carbaryl.
That still leaves the home gardener in the dark about the possible dangers of carbaryl. Of course, organic gardeners don't use Sevin - they know it's not necessary and it may not be safe. But for those who may still be wondering ir it's OK to use a little hare's an ORGANIC GARDENING commentary on a carbaryl label.
back to the rest of the story (page 2).