BISMARCK, N.D. — Environmental regulators in the United States and Canada have developed a joint label for farm chemicals that officials say could save American farmers millions of dollars.

The Environmental Protection Agency and its Canadian counterpart announced last week the first North American Free Trade Agreement label — for a herbicide, marketed as Far-GO in the United States and as Avadex in Canada, that can be used for weed control for a wide range of crops.

U.S. farmers have long wanted to import chemicals from Canada because they say those are often cheaper north of the border, but so-called "harmonization" bills have failed in Congress. One impediment to getting legislation was the perception that a joint U.S.-Canadian label would be too cumbersome to create, said North Dakota agriculture commissioner Roger Johnson

"We have proven that NAFTA labels are possible," said Johnson, who worked on the initiative with federal regulators and chemical industry representatives.

"U.S. farmers could save $178 million a year if they had free access to similar pesticides on the Canadian side of the border," he said, citing a 2005 study by North Dakota State University researchers.

Jim Gulliford, an assistant EPA administrator, said 12 additional chemicals are in line for labels.

"Joint U.S.-Canadian pesticide labels are a reality," he said. "We can use this as a strategy to reduce trade barriers between our two countries."

Dean Wanner, a spokesman for Arizona-based Gowan Company LLC, which makes Far-GO and Avadex, said the NAFTA label process will benefit chemical manufacturers because it means their product can move freely across the border. That eliminates the expense of different packaging and labeling, he said.

"It's a matter of efficiency," Wanner said.

He said industry competition would stop companies from raising chemical prices in Canada rather than reducing them in the United States. Farm chemical companies also say prices reflect the cost of different labeling requirements in the two countries, which must be added to the cost of the herbicide.

NAFTA labeling for farm chemicals is voluntary and there are other factors companies must weigh, said Jay Vroom, president of CropLife America, a pesticide trade association based in Washington, D.C. For example, he said, one company found it would be quicker to get a U.S. label than a NAFTA label for its product, a decision that he said ultimately benefited American farmers.

"I think there will be more" NAFTA labels, he said, but added "there's not going to be a landslide of dozens and dozens of products that are going to get NAFTA labels overnight."