William Waren, a trade policy analyst with the environmental group Friend of the Earth, said the issue is sensitive as a growing body of scientific research links exposure to toxic chemicals to rising rates of cancer, learning disabilities, asthma, fertility problems, Alzheimer’s disease and Parkinson’s disease.

The talks on the proposed Transatlantic Trade and Investment Partnership promise to move slowly. They’re not expected to wrap up until the end of next year, at the earliest, and it won’t come as much of a surprise if they’re pushed into 2015. Froman said the substance of the talks will dictate when they end. But he noted that the terms of the current European Commission expire at the end of 2014; he said that will provide “a useful timetable” for negotiators.

As a result, no one expected any big developments during the first five days of negotiations.

Eric Shimp, a former U.S. trade negotiator who’s now a policy adviser on global trade with Alston & Bird, a Washington law firm, called the first round of talks with the 28-member European Union “an elaborate exercise in jockeying for position.”

“Even though it’s the first round, it’s really just the horses being put into the chutes,” he said. “The gates aren’t really open.”

On the European side, the jockeying began last month, with France making the most noise.

First Paris threatened to block the talks until the country won assurance that the negotiations would exclude France’s entertainment and cultural sectors. And then last week, the French government argued for a temporary suspension of the talks in response to reports that the U.S. government had been spying on European countries.

While negotiators spent the bulk of the week meeting privately at the White House Conference Center next to Lafayette Square, they got an earful Wednesday when they opened the doors for three hours of “stakeholder presentations,” meeting with more than 350 people who had registered in advance.

The interest groups presented a long and diverse list of demands, reflecting the deal’s broad scope.

Oceana, a group seeking to protect oceans, wants a pact that ends European fishing subsidies and cracks down on illegal fishing.

The National Association of Manufacturers wants to make sure that an agreement protects trade secrets of companies.

The AFL-CIO wants to protect “Buy America” laws that allow the federal government and states to give preferential treatment to U.S. companies over foreign competition in awarding contracts.

PhRMA, the Pharmaceutical Research and Manufacturers of America, wants to make sure that U.S. drug patents are protected.

And the Sierra Club wants to make sure that environmental laws don’t get overlooked if the United States begins exporting more natural gas.

Some of the toughest issues will involve food standards, with Europeans wary of Americans’ genetically modified products, hormone-injected meat and cleaning methods at processing plants, including the common practice of dipping chicken in chlorine to get rid of contamination.

U.S. officials sought to assuage the concerns.

“Nothing being negotiated would prevent the United States or the EU from regulating in its own citizens’ public interest – in the financial sector, in the health sector, or with regard to safety or the environment or any other regulatory area,” said Andrea Mead, spokeswoman for the Office of the U.S. Trade Representative. “We wouldn’t negotiate this away.”