That claim could be an issue for Juul because it might not be fully truthful.

Under the Food, Drug and Cosmetic Act of 1938, the F.D.A. can pursue a civil case if the labeling of a product does not provide “adequate warnings against use in those pathological conditions or by children where its use may be dangerous to health.” Last month, the F.D.A. issued a warning letter to Juul, asserting that the company marketed its e-cigarettes “as modified risk tobacco products without an F.D.A. order in effect that permits such sale or distribution.”

The letter said Juul’s products “are tobacco products because they are made or derived from tobacco and intended for human consumption.” The agency added that Juul’s claim that its products are “‘99 percent safer’ than cigarettes, ‘much safer’ than cigarettes, ‘totally safe’ and ‘a safer alternative than smoking cigarettes’ was particularly concerning because these statements were made directly to children in school.”

Section 331 of the Food, Drug and Cosmetic Act prohibits the “receipt in interstate commerce of any food, drug, device, tobacco product or cosmetic that is adulterated or misbranded.” If Juul were found to have shipped a misbranded product, or one that was not approved by the F.D.A. as a tobacco product, it may be subject to criminal prosecution.

Because that is a misdemeanor, the government would not be required to prove any intent to violate the act. The penalty is imprisonment for up to one year and a fine of $1,000. In other words, it is a strict liability provision that can be brought against the company and any individuals responsible for marketing to children.

In addition, the F.D.A. can impose a civil penalty of $15,000 for each violation, not to exceed $1 million, and can seek an injunction to stop sales of products that are found to have violated Section 331.