Washington ? New government guidelines allowing limited use of pesticides and antibiotics in organic farming have provoked a backlash from farmers and consumer groups who say they devalue the federal organic label.

With a weakening of the standards, “consumers and farmers could lose confidence in the USDA label,” said Pam Riesgraf, who owns a 60-cow organic dairy farm in Jordan, Minn., about 35 miles outside Minneapolis.

The guidelines, announced last month by the Agriculture Department, were in response to questions from government certifiers, said Barbara Robinson, a deputy administrator in charge of the USDA’s National Organic Program, which oversees certification of the organic label. The fast-growing organic food industry has sales of about $10.8 billion a year.

“We want them to apply the standards consistently,” she said. “It’s ludicrous to assume that the department said, ‘The heck with the law, let’s change the regulations.”‘

That’s what some critics think happened.

“They are new interpretations that are contrary to the regulations as written, and they contradict previous policy 100 percent,” said Jim Riddle of Winona, Minn., vice chairman of the 15-member National Organic Standards Board, which recommends policy to the Agriculture Department.

Sen. Pat Leahy, a Vermont Democrat who wrote the 1990 Organic Food Productions Act, plans to circulate a letter this week to urge Agriculture Secretary Ann Veneman to rescind the new guidelines.

At issue are several guidance statements and enforcement directives issued last month. Specifically, they allow:

l Organic producers to use pesticides that may contain inert chemical ingredients even if a “reasonable effort” fails to determine what the ingredients are. Pesticide makers are not required to list all inactive ingredients in their products.

l Milk from a cow that has been treated with antibiotics to be sold under the USDA organic seal as long as the cow has been antibiotic-free for 12 months.

Pam Riesgraf and her husband, Jeff, are shown on their organic dairy farm in Jordan, Minn. The Riesgrafs say new U.S. Department of Agriculture guidelines, allowing the limited use of pesticides and antibiotics, are making a sham of the federal organic label.

l Ground fish to be used as a protein supplement in livestock feed.

Consumer and organic groups are angry at both the end result and the process, saying the department should have consulted with the standards board before issuing its guidance statements.

“It was always our view this was a public-private partnership,” said Michael Sligh, the board’s founding chairman, which helped develop original guidelines in the 1990s for the federal program. “We’re worried about a breakdown.”

Robinson said agency officials didn’t consult with the organic standards board because they believed they were simply implementing the regulations.

“I suppose we’ll give them more of a heads-up (next time),” Robinson said.

Urvashi Rangan, a scientist at Consumers Union in Yonkers, N.Y., said the new directives weakened the value of the organic label. She cited guidelines allowing fishmeal in cattle feed as an example.

“We have some questions as to whether cows eat fish to begin with,” she said. “The second issue is that fish are not certified as organic. And we already know that fish have some problems like PCPs and mercury.”

As for the antibiotics in cows, Rangan said the issue wasn’t that people would be exposed to the hormones 12 months after the cow has been antibiotic-free.

“It’s a question of adding value, and is the milk worth the premium?” she said. “Organic is a program that says you don’t use antibiotics.”