The U.S. Food and Drug Administration admonished the electric cigarette company Juul Labs last week for claims that its products are safer than conventional cigarettes.

In a letter dated September 9, the FDA warned the company over its assertions that the Juul is “much safer than cigarettes,” and that the “FDA would approve it any day,” among other claims that the FDA says it didn’t authorize.

The agency said it determined that the company claimed, in presentations to students made by Juul representatives, that its e-cigarettes constituted “modified risk tobacco products without an FDA order in effect that permits such sale or distribution.”

“Referring to your [electronic nicotine delivery system, or “ENDS,”] products as ‘99% safer’ than cigarettes, ‘much safer’ than cigarettes, ‘totally safe,’ and ‘a safer alternative than smoking cigarettes’ is particularly concerning because these statements were made directly to children in school,” the letter said. “Our concern is amplified by the epidemic rate of increase in youth use of ENDS products, including JUUL’s products, and evidence that ENDS products contribute to youth use of, and addiction to, nicotine, to which youth are especially vulnerable.”

The FDA asked Juul for a written response to the letter within 15 days of its receipt detailing how it intends to comply with the law going forward.

The letter marks the latest brushback against the e-cigarette industry in the wake of a string of hospitalizations and deaths linked to the products. A California man this week became the seventh person to die from a vaping-related illness, following fatalities in Oregon, Minnesota, Indiana, Illinois and Kansas. In addition, there are 450 cases of people being admitted to the hospital for illnesses potentially caused by e-cigarette use currently under investigation.

Those incidents prompted the Trump administration to announce last week plans to impose a ban on flavored e-cigarette products, which are seen as attempts to market to children.

“The Trump Administration is making it clear that we intend to clear the market of flavored e-cigarettes to reverse the deeply concerning epidemic of youth e-cigarette use that is impacting children, families, schools, and communities,” Alex M. Azar II, the secretary of Health and Human Services, said at the Oval Office announcement. “We will not stand idly by as these products become an on-ramp to combustible cigarettes or nicotine addiction for a generation of youth.”

President Trump, appearing at the announcement alongside Azar, noted that “vaping has become a very big business, as I understand it, like a giant business in a very short period of time.”

“But we can’t allow people to get sick and we can’t have our youth be so affected,” Trump said.

“We’re going to have to do something about it,” he added.