Last year $2.4 billion worth of products were sold with a label saying they do not contain ingredients from genetically modified organisms, but the claim wasn't backed by any government regulatory agency.
Instead, it came from the Non-GMO Project, a nonprofit organization that offers third-party verification that food products are not genetically modified.
Unlike items labeled organic, non-GMO products do not receive endorsement from the Department of Agriculture or the Food and Drug Administration. Those regulators have specific criteria for organic products, and consumers know that any food with an organic label has met those standards.
Brands such as Silk, Kashi and Simply Soy Yogurt have turned to the GMO Project for support to tout their products as non-GMO.
"Consumers want non-GMO choices, so we are working with food companies and retailers to make sure that [these options are] available," said Megan Westgate, executive director of the Non-GMO Project. "Our efforts do not hinge on government regulations or decisions about whether or not to label."
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Natural food retailers started the Non-GMO Project, according to Westgate.
"They were getting a lot of questions from shoppers about how to avoid GMOs. It became clear that in the absence of mandatory labeling we needed to have a third-party verification system," she said.
Since 2008 the organization has supplied a verification mark for products that have undergone its review process. More than 500 brands carry the Non-GMO seal.
The process of earning the label is rigorous, and ongoing testing is required for all ingredients that are at high risk of GMO contamination, Westgate said.