The United States has stockpiled millions of pounds of methyl bromide, a pesticide that depletes the ozone layer, according to newly public documents -- information that could create a stir during international negotiations next month, when the Bush administration seeks permission to produce more.
Methyl bromide has been banned for almost two years under the United Nations' Montreal Protocol. Under that pact -- designed to stop the thinning of the ozone layer, which shields the planet from harmful ultraviolet radiation -- the United States is granted annual exemptions to use the chemical at farms that grow California strawberries, Florida tomatoes and other crops deemed "critical."
The new Environmental Protection Agency data, which show that the stockpile is big enough to provide those farmers more than a year's supply, are likely to put the Bush administration in the position of defending the size of the U.S. reserve while seeking approval for chemical companies to manufacture more.
In a negotiating process that already has been highly contentious, nations that ratified the U.N.'s 1987 treaty meet yearly to allocate how much methyl bromide each can use and produce. When the parties convene in New Delhi in late October to set 2008 allocations, it will be the first time they have had access to information about the size of the U.S. stockpile.
Under the treaty, nations are allowed to produce more only if "methyl bromide is not available in sufficient quantity and quality from existing stocks."
In 2004, nearly 29 million pounds were stockpiled by U.S. chemical companies, but the Bush administration received permission from the United Nations to produce an additional 17 million pounds that year, according to newly released EPA data. That amounts to twice as much as U.S. farmers needed last year.
Last year, the inventory dropped to 22 million pounds, but an additional 15 million pounds were produced -- again totaling twice as much as farmers will use.
Methyl bromide, a highly toxic gas used to sterilize soil and kill pests, is considered the most powerful ozone destroyer currently in large-scale use. Scientists say the thinned ozone layer has increased the rate of skin cancers and cataracts, and has damaged ocean plankton, coral reefs and wildlife.
Environmental groups say the United States is hoarding tons of the chemical while convincing other U.N. countries that it must produce more every year. They say the stockpile should be reduced before new production is allowed or else its use will be prolonged.
"If we were following the treaty's rules, we wouldn't be producing any new material until the stockpile was drawn down. But for three years, the EPA has kept authorizing new production and adding to the stockpile," said David D. Doniger, a policy director of the Natural Resources Defense Council, a national environmental group.
But Drusilla Hufford, director of the EPA's stratospheric protection division, said an ample inventory was needed to provide a "cushion" to protect U.S. food growers from a "shock to the system" if production was interrupted.
The stock of methyl bromide, which has dropped 75% since 1991, continues to decline about 20% per year, which Hufford said allowed an "orderly reduction" as farmers and federal officials collaborated to find safer pest-killing alternatives.
"We need to have enough in the pipeline to ensure we don't have a sudden shortage," she said.
The EPA data also show for the first time that growers other than U.N.-designated "critical users" -- those whose market would be disrupted and that have no viable pest-killing alternatives -- are drawing from the U.S. stock.
U.S. tomato and strawberry growers and others deemed critical used 21 million pounds last year, but the total used exceeded 23 million pounds.
It is unknown which farms are using the 2.5 million pounds or what crops they grow. Because the stockpile was produced before the 2005 U.N. ban, EPA officials say, farmers can legally buy methyl bromide from chemical companies without seeking U.N. and EPA authority.
Chemtura Corp. of Middlebury, Conn., is the only U.S. methyl bromide producer. Its manager of fumigant product issues, David McAllister, said Wednesday that the stockpile was being "managed very responsibly" by the EPA and had dropped by nearly half in three years.
He said maintaining at least a year's reserve was critical for agriculture in case "there were a catastrophic interruption in supply or some sort of pest infestation that was unanticipated."
"Clearly if economically and technically viable alternatives were available, growers would be using them instead," McAllister said.
The EPA's Hufford said that unlike most countries, the U.S. agricultural sector was huge and diverse and faced a variety of pests, making its crops more vulnerable than those in the European Union and consequently more dependent on methyl bromide.