Correction: This article incorrectly said the Food and Drug Administration has found that genetically modified salmon is not “materially” different from its conventional counterpart. FDA scientists reviewing genetically modified salmon from a company called AquaBounty Technologies said, “We have found no biologically relevant difference between food from [AquaBounty salmon] and conventional Atlantic salmon,” but the agency has not yet decided whether the genetically modified salmon is “materially” different from conventional salmon. A finding of no material difference would prohibit the FDA from requiring special labels on the modified salmon.

In the absence of a federal law requiring labels for genetically modified food, 14 states are debating whether to mandate labeling for modified foods sold within their borders.

The discussions, taking place from Albany, N.Y., to Sacramento, come as federal regulators weigh approval of the first genetically modified animal, a salmon, for human consumption.

In four states — California, Oregon, Vermont and Alaska — lawmakers are considering legislation that would pertain only to fish. The other states, including New York, are grappling with measures that would require all foods made from genetically modified ingredients to disclose that information on the label.

“The fact that you see these measures popping up is kind of a response to the vacuum in Washington,” said Jared Huffman, a Democratic member of the California State Assembly and sponsor of a bill to require labeling for genetically modified salmon. His measure was debated Wednesday by a key appropriations committee but fell three votes short of the number needed for passage. The committee chairman, who supports the bill, called for a second vote to be held May 25. If approved, it will head to the full assembly.

Genetically modified food is created when a plant or organism receives genetic material from a different source — sometimes a different species — to produce a desired trait. Creators of the genetically altered salmon took an Atlantic salmon and inserted a growth hormone from a Chinook salmon and a gene from an ocean pout. The result is a salmon that grows twice the normal rate. Critics have dismissed it as “Frank­enfish.”

The Food and Drug Administration says it cannot require a label once it determines the altered food is not “materially” different from its conventional counterpart, which it has done in the case of the salmon.

But Huffman said that the genetically modified salmon, which has not yet received FDA approval, is not the same as a wild salmon, and that consumers deserve to know the difference.

“If you’ve got a product on the shelf next to wild salmon and it’s genetically engineered, raised in pens in a factory facility — probably priced a lot less — and you don’t even label it, the consumer will think it’s salmon,” Huffman said, adding that the cheaper competitor would threaten California’s struggling wild salmon industry.

The controversy comes as Americans show increased interest in their food — where it is grown, how it is produced and what it contains.

“There’s been tremendous, overwhelming support from constituents on this,” Huffman said.

Since the FDA approved the first genetically altered material for use in food in 1992, the use of genetically engineered crops has skyrocketed; 93 percent of last year’s soybean crop was genetically engineered, according to the U.S. Agriculture Department.

By-products of those crops — soy lecithin, for example — are found in thousands of processed foods from chocolate bars to breakfast cereal. Genetically modified ingredients are present in about 80 percent of conventional processed food in the United States, according to the Grocery Manufacturers Association, a trade organization opposed to labeling measures.

National groups see the California debate as a proxy for a larger fight over genetically engineered food.

“It’s a big state, and a lot of trends start here, and so there’s a big imperative to try to move this California bill along,” said James Ferro, aquaculture policy analyst for the Ocean Conservancy, which is a co-sponsor of Huffman’s bill.

Opponents include the Biotechnology Industry Organization and agriculture groups such as the California Farm Bureau, which has little to do with fishing but plenty to do with genetically modified crops such as wheat, corn and soy.

“When it comes to food, this is a sensitive issue,” said Ab Basu of BIO. “We believe if you raise questions and think it’s okay to label in this particular instance, that argument could be used on other types of genetically engineered food.”

The labeling issue is being used by groups intent on restricting biotechnology, Basu said. He said a flurry of similar bills about a decade ago were largely defeated.

Alaska, with a sizable salmon-fishing industry, is the only state with an existing labeling law, which requires identification of genetically engineered fish in the marketplace.

Diana Urban, a Democratic lawmaker in Connecticut, filed legislation this year to require labeling for all genetically modified foods. Her measure stalled in committee, but a Democratic colleague, state Rep. Richard Roy, embraced the cause after seeing the documentary film “Food Inc.” and plans hearings when the legislature reconvenes.

Urban, who serves on the board of the National Caucus of Environmental Legislators, said the group is trying to pass slightly different labeling bills across the country, with an eye toward creating a patchwork of state rules that would frustrate the food industry to the point it would support a federal labeling law.

“If each state makes it different, then the big corporations will be begging the federal government to step in and do regulation,” Urban said. “That’s a strategy.”

On Capitol Hill, several bills are pending in the House and the Senate that would variously ban genetically altered salmon, require its labeling or require labeling of all genetically modified food. In the past, similar bills have not come close to passage.

Since the European Union rolled out the first labeling requirements for genetically modified foods in 1997, at least 15 countries have mandated it. In many of those countries, manufacturers have stopped using genetically modified ingredients in their foods because they fear the required label will hurt sales.