But E.P.A. scientists had concluded that these laminate products — millions of which are sold annually in the United States — posed a particular risk. They said that when thin layers of wood, also known as laminate or veneer, are added to furniture or flooring in the final stages of manufacturing, the resulting product can generate dangerous levels of fumes from often-used formaldehyde-based glues.

Industry executives, outraged by what they considered an unnecessary and financially burdensome level of testing, turned every lever within reach to get the requirement removed. It would be particularly onerous, they argued, for small manufacturers that would have to repeatedly interrupt their work to do expensive new testing. The E.P.A. estimated that the expanded requirements for laminate products would cost the furniture industry tens of millions of dollars annually, while the industry said that the proposed rule over all would cost its 7,000 American manufacturing facilities over $200 million each year.

“A lot of people don’t seem to appreciate what a lot of these requirements do to a small operation,” said Dick Titus, executive vice president of the Kitchen Cabinet Manufacturers Association, whose members are predominantly small businesses. “A 10-person shop, for example, just really isn’t equipped to handle that type of thing.”

Big industry players also weighed in. Executives from companies including La-Z-Boy, Hooker Furniture and Ashley Furniture all flew to Washington for a series of meetings with the offices of lawmakers including House Speaker John Boehner, Republican of Ohio, and about a dozen other lawmakers, asking several of them to sign a letter prepared by the industry to press the E.P.A. to back down, according to an industry report describing the lobbying visit.

Within a matter of weeks, two letters — using nearly identical language — were sent by House and Senate lawmakers to the E.P.A. — with the industry group forwarding copies of the letters to the agency as well, and then posting them on its website.

The industry lobbyists also held their own meeting at E.P.A. headquarters, and they urged Jim Jones, who oversaw the rule-making process as the assistant administrator for the agency’s Office of Chemical Safety and Pollution Prevention, to visit a North Carolina furniture manufacturing plant. According to the trade group, Mr. Jones told them that the visit had “helped the agency shift its thinking” about the rules and how laminated products should be treated.

Image Becky Gillette wants strong regulation of formaldehyde. Credit Beth Hall for The New York Times

The resistance was particularly intense from lawmakers like Mr. Wicker of Mississippi, whose state is home to major manufacturing plants owned by Ashley Furniture Industries, the world’s largest furniture maker, and who is one of the biggest recipients in Congress of donations from the industry’s trade association. Asked if the political support played a role, a spokesman for Mr. Wicker replied: “Thousands of Mississippians depend on the furniture manufacturing industry for their livelihoods. Senator Wicker is committed to defending all Mississippians from government overreach.”