Health groups are calling on the Food and Drug Administration (FDA) to investigate the therapeutic claims electronic cigarette manufacturers are allegedly making in reference to their products.

The American Cancer Society’s Cancer Action Network, the American Lung Association, the American Heart Association, the Campaign for Tobacco-Free Kids and Truth Initiative sent a letter to Janet Woodcock, the director of FDA’s Center for Drug Evaluation and Research, calling for action last week.

The groups said Truth in Advertising (TINA) reviewed more than 150 manufacturer and seller websites and found claims that e-cigarettes helped smokers stop smoking. To make these claims, the groups said FDA has to sign off on them first.

“The TINA Survey suggests that violations of federal law on a massive scale are taking place in the marketing of e-cigarettes,” the groups said in their letter. “We therefore urge FDA to immediately commence an investigation of the claims being made by these companies and take prompt and appropriate enforcement action against those found to be violating the law.”