The FDA has issued the first warning letters to e-cigarette companies for illegal claims on their websites, according to an article published in JAMA.

According to the article, the FDA says it has the authority to issue the warning letters because e-cigarettes “are made or derived from tobacco and are intended for human consumption.”

On their websites, the 3 companies—2 in the United States and 1 in the United Kingdom—mislead consumers into believing that their e-cigarettes are approved by the FDA, safe for use, or less harmful because they are manufactured under FDA oversight, the agency said. For example, the letter to the UK company said its website featured a graphic image of a “Certificate of FDA Registration.”