Whole Foods is the first supermarket chain to require its suppliers to put GMO labels on their products, a mandate that must be met by 2018. (Carline Jean/Sun Sentinel/MCT via Getty Images)

By Carey Gillam and Lisa Baertlein

April 16 (Reuters) - The Vermont Senate passed a bill on Wednesday that would make the state the first in the United States to enact mandatory labeling of foods made with genetically modified crops.

"We are really excited that Vermont is going to be leading on this," said Falko Schilling, a spokesman for the Vermont Public Interest Research Group, which backed the bill.

The bill, approved 28-2 by the Senate, has already passed the Vermont House of Representatives. It now goes back to the House to see if members will approve changes made by the Senate.

The law is set to take effect July 1, 2016.

The move in Vermont comes as the developers of genetically modified crops and U.S. grocery manufacturers push for passage of an opposing bill, introduced in Congress last week, that would nullify any state law that requires labeling of foods made with genetically modified crops.

The Vermont law passed by the Senate would do just that - processed foods that contain genetically modified corn, soybeans or other GMO ingredients and sold at retail outlets would have to be labeled as having been produced or partially produced with "genetic engineering."

Andrea Stander, a spokesperson for the Vermont Right to Know GMOs coalition, said they expect the biotech industry to sue in an attempt to stop enactment of the bill. As such, the language of the bill includes formation of a fund that would pay legal bills.

"It's not just Vermont," said Stander. "This affects everyone who eats. Consumers all across the country have woken up to the fact that we've become an unregulated feeding experiment by the biotech industry. People want to know if their foods are made with these ingredients. This gives people the choice."

Consumer groups say labeling is needed because of questions both about the safety of GM crops - known as GMOs - for human health and the environment.

The language of the Vermont bill states that foods made with genetically engineered crops "potentially pose risks to health, safety, agriculture, and the environment" and should be labeled.

Last October, a group of 93 international scientists issued a statement saying there was a lack of empirical and scientific evidence to support what they said were false claims the biotech industry was making about a "consensus" on safety.

The group said there needed to be more independent research as studies showing safety tend to be funded and backed by the biotech industry.

But GMO crop developers like Monsanto, and their backers say genetically modified crops are proven safe.

"This debate isn't about food safety," said Karen Batra, spokeswoman for the Biotechnoloy Industry Organization. "Our science experts ... point to more than 1,700 credible peer-reviewed studies that find no legitimate concern."

Batra said mandatory labeling creates needless extra costs and complications for farmers and the food industry.

Ballot measures in California in 2012 and last year in Washington state narrowly lost after Monsanto and other GMO crop developers and members of the Grocery Manufacturers Association poured millions into campaigns to defeat the measures.

The Vermont bill makes it illegal to describe any food product containing GMOs as "natural" or "all natural." Unlike bills passed last year in Maine and Connecticut, which require other states to pass GMO labeling laws before they can be enacted, Vermont's law contains no such trigger clause. (Editing by Bernadette Baum)