Syngenta, a Swiss chemicals company, produces one of America’s most popular herbicides. It is called atrazine, and 73.7 million pounds of the chemical compound were applied in the United States in 2013. It was used on more than half of all corn crops, two-thirds of sorghum and up to 90 percent of sugar cane.
But Syngenta cannot sell atrazine to farms in its own backyard. The weed killer is banned as a pesticide in the European Union as well as in Switzerland over concerns that it is a groundwater contaminant. Syngenta, however, did not get the memo.
Even though the European Union banned atrazine over a decade ago, the company has long insisted that the pesticide was not banned. On one corporate website, Syngenta points to “anti-atrazine activists” who “claim that ‘atrazine’ is banned in the European Union. This is patently false.”
Another Syngenta-backed site, “Saving the Oasis,” also blames “anti-atrazine activists.” And another such site, AGSense, says, “We’ve known it all along, and now you know it too: Atrazine is not banned in the European Union.”
The company has repeated its assertion to reporters.
“It is not banned,” Ann Bryan, a spokeswoman for the company, said in an email, though she acknowledged that “countries in the E.U. currently do not use atrazine.”
Companies are perhaps understandably sensitive about revealing too much about the gulf that exists between American and European regulation of pesticides and other chemicals.
Generally speaking, the European approach incorporates the so-called precautionary principle and requires companies to establish that new chemicals are safe before they are put on the market. The American approach puts the onus on regulators to show some evidence of danger before taking action against new chemicals.
Scores of chemicals that are banned or tightly restricted in the European Union are allowed in the United States. One recent analysis by the Center for International Environmental Law, a Washington-based advocacy group, found 82 instances of pesticides allowed in the United States but barred or restricted in Europe.
This disparity can make selling products on one side of the Atlantic that are banned on the other uncomfortable, though few companies have tried a semantic maneuver quite like Syngenta’s.
“The use of atrazine as a herbicide/pesticide is banned in the E.U.,” Mikko Vaananen, a spokesman for the European Chemicals Agency, said in an email, adding that it was still allowed as an intermediate substance used in industry to create new chemicals. European Union government documents, from formal filings to informal newsletters, also use the term “banned.”
Sensitivity over regulatory gaps between the United States and Europe has flared during trans-Atlantic trade talks, which have been underway since 2013 in hopes of reaching a broad deal that they say could save businesses tens of billions of dollars a year.
The talks are considered more of a priority for Europe, which is mired in deflation and high unemployment, than the United States, where the economy is recovering. But both sides have made reaching an agreement a cornerstone of trade policy.
Finding commonalities in trans-Atlantic regulations is one of the main efforts of the talks, since much work has already been done to reduce tariffs. As a result, though, an increasing number of critics of the process are concerned that the outcome could favor corporations more than consumers. Advocacy groups have particularly focused on chemicals, given the disparities in policy.
Government negotiators on both sides, however, call concerns misguided and say they have released documents and provided assurances aimed at clarifying their intentions.
Trevor Kincaid, a spokesman for the United States trade representative, said in a statement: “We have made it clear privately and publicly, in Europe and the U.S. in multiple languages, and in a variety of formats: Neither one of us is looking to abandon our unique, high-standard, approaches to chemical regulation. Period.”
Daniel Rosario, a spokesman for the European Commission, said in his own statement: “We have made clear since the beginning of the negotiations that neither full harmonization nor mutual recognition are feasible on the basis of the existing framework legislations,” adding, “It is therefore equally clear that we are not aiming at a convergence of E.U. and U.S. chemicals regulations.”
Such statements have done little to quell critics of the talks.
In a letter to trade officials last year, more than 100 advocacy groups accused American officials of “promoting an approach to regulatory cooperation that would export to the E.U.” an American regulatory approach that “has proved to thwart the timely promulgation of important regulations.”
Baskut O. Tuncak, a senior lawyer at the Center for International Environmental Law, said that in his view the chemical proposals that have surfaced so far “reflect a lot of industry’s demands and their concerns with more protective E.U. policies.” He added that proposed changes could “slow or stop and possibly weaken efforts to develop stronger chemical regulation in either the E.U. or the U.S.”
In some cases it is European companies that have benefited from American chemical policy, and few have been as vigilant in protecting their brands as Syngenta.
The company’s feud with Tyrone Hayes, a professor at the University of California, Berkeley, whose research it initially underwrote, has reached extraordinary levels, and its fight with Mr. Hayes was the subject of a lengthy New Yorker article last year.
Mr. Hayes’s research found that atrazine chemically castrates male frogs and even changes the sex of some of them.
“I’m not surprised at anything they say/do,” Mr. Hayes said in an email.
In Europe, the principal concern with atrazine was that it was showing up in groundwater at concentrations above what was allowed.
It was banned because of its “long-term persistence in the environment, together with toxicity for wildlife and possible link to effects on human health,” according to one recent publication from the commission.
In the United States, atrazine is undergoing a periodic review process that is expected to wrap up in 2016. The Environmental Protection Agency said in a statement that the policy difference stemmed from Europe’s decision to set a limit “for all pesticides in water, regardless of the level of risk.”
“The E.U. banned atrazine because of monitoring data showing that levels of atrazine might exceed” that limit, the E.P.A. said.
Ms. Bryan of Syngenta said atrazine’s safety record had been established by thousands of studies and called it “one of the most closely examined pesticides in the world.” She added that Syngenta did not manufacture it in Europe.
Critics cite Mr. Hayes’s work and other studies that have linked atrazine to birth defects and identified it as a contaminant of American drinking water. The company paid $105 million in 2012 to settle a class-action lawsuit from Midwestern water utilities over atrazine levels in the water supply.
Asked several times to explain her company’s understanding of European Union policy, Ms. Bryan referred a reporter to a frequently asked questions page on the website of a government agency in Australia, where atrazine is also used. The passage said that atrazine was not banned in Europe.
Asked about the passage and why it said atrazine was not banned in Europe, a spokeswoman for the Australian Pesticides and Veterinary Medicines Authority said her agency was reviewing it “to reduce confusion.”