By MARY CLARE JALONICK, Associated Press

WASHINGTON (AP) — The Agriculture Department has developed a new government certification and labeling for foods that are free of genetically modified ingredients.

USDA's move comes as some consumer groups push for mandatory labeling of the genetically modified organisms, or GMOs.

The certification is the first of its kind, would be voluntary — and companies would have to pay for it. If approved, the foods would be able to carry a "USDA Process Verified" label along with a claim that they are free of GMOs.

Agriculture Secretary Tom Vilsack outlined the new certification in a May 1 letter to USDA employees, saying it was being done at the request of a "leading global company," which he did not identify. A copy of the letter was obtained by The Associated Press.

A USDA spokesman confirmed that Vilsack sent the letter but declined to comment on the certification program. Vilsack said in the letter that the certification "will be announced soon, and other companies are already lining up to take advantage of this service."

Companies can already put their own GMO-free labels on foods, but there are no government labels that only certify a food as GMO-free. Many companies use a private label developed by a nonprofit called the Non-GMO Project. The USDA organic label also certifies that foods are free of genetically modified ingredients, but many non-GMO foods aren't organic.

Vilsack said the USDA certification is being created through the department's Agriculture Marketing Service, which works with interested companies to certify the accuracy of the claims they are making on food packages — think "humanely raised" or "no antibiotics ever." Companies pay the Agricultural Marketing Service to verify a claim, and if approved, they can market the foods with the USDA process verified label.

"Recently, a leading global company asked AMS to help verify that the corn and soybeans it uses in its products are not genetically engineered so that the company could label the products as such," Vilsack wrote in the letter. "AMS worked with the company to develop testing and verification processes to verify the non-GE claim."

Genetically modified foods come from seeds that are originally engineered in laboratories to have certain traits, like resistance to herbicides. The majority of the country's corn and soybean crop is now genetically modified, with much of that going to animal feed. GMO corn and soybeans are also made into popular processed food ingredients like high-fructose corn syrup and soybean oil.

The government says GMOs on the market now are safe so mandatory labels aren't needed. Consumer advocates pushing for mandatory labeling say shoppers still have a right to know what is in their food, arguing that not enough is known about the effects of the technology. They have supported several state efforts to require labeling, with the eventual goal of having a federal mandatory label set by the Food and Drug Administration.

An Associated Press-GfK poll in December showed that two thirds of Americans support the labeling, while fewer said genetically modified ingredients are important in judging whether a food is healthy. Some of the respondents said their support of labeling was more about accountability in the food industry than the safety of GMOs.

Vermont became the first state to require the labeling in 2014, and that law will go into effect next year if it survives a legal challenge from the food industry.

The USDA label is similar to what is proposed in a GOP House bill introduced earlier this year that is designed to block such mandatory GMO labeling efforts around the country. The bill, introduced by Rep. Mike Pompeo, R-Kan., provides for voluntary USDA certification and would override any state laws that require the labeling. The food industry has strongly backed Pompeo's bill, arguing labels would be misleading because GMOs are safe.

Pompeo said USDA's move shows his approach is gathering support.

"I look forward to working with the secretary and with my colleagues in Congress to ensure that we come to the best possible policy to provide families in Kansas and America with clarity at the grocery store affordable and abundant food supply," he said.

Consumer advocates who are pushing for mandatory labeling say the voluntary USDA labels aren't sufficient to help consumers know what is in their food, arguing that labels that are on some foods but not others could just lead to more confusion.

Gary Hirshberg, chairman of the Just Label It campaign and co-founder of the organic yogurt company Stonyfield Farm, said the labels were a small step in the right direction but more is needed.

"Mandatory labeling of GMOs would allow consumers to vote with their dollars and have a say in the type of agriculture they would like to see in this country," Hirshberg said.

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