• Regulators with the US Food and Drug Administration sent a warning letter to e-cig company Juul on Monday.
  • The warning said Juul wrongly painted its devices as safer than cigarettes and marketed them intentionally to young people.
  • The letter comes on the heels of a media blitz by Juul in which its CEO first apologized to parents of kids addicted to Juul, then warned people against using them, and then said they were helping smokers quit.
  • FDA criticzed Juul for calling its products “totally safe” in a presentation to children at school.
  • Juul said in an e-mailed statement that it’s “reviewing the letters and will fully cooperate.”
  • Visit Business Insider’s homepage for more stories.

Federal regulators just put Juul on notice.

The $38 billion e-cig company, partially owned by tobacco giant Altria, received a warning letter on Monday from the US Food and Drug Administration saying that it wrongly portrayed its devices as safer than cigarettes and marketed them intentionally to youth, including at high schools.

E-cigarettes like the Juul are sometimes called “ENDS,” for electronic nicotine delivery systems.

“Referring to your 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 FDA letter reads.

"Our concern is amplified by the epidemic rate of increase in youth use of ENDS products, including JUUL's products," the letter said.

Juul said in an e-mailed statement that it's "reviewing the letters and will fully cooperate."

A teen vaping epidemic

The FDA warning is another setback for Juul amid months of bad news for the e-cig maker, and for vaping in general. Juul has embarked on a media tour over the last several months, as its sleek devices face increasing scrutiny over their role in sparking a teen vaping epidemic. Use of Juuls has also potentially been tied to seizures, Bloomberg News reported.

Meanwhile, regulators are also investigating five deaths and more than 450 cases of serious lung disease tied to vaping. For now, that investigation is mainly focused on people who said they vaped marijuana, but some reports included mention of nicotine as well.

Juul has conducted a series of media appearances over the last several months. In July, Juul CEO Kevin Burns apologized to parents of kids addicted to Juul. Last month, Burns warned people against using the Juul. In the same appearance, Burns also said his company was helping smokers quit.

Read more: Here's the real reason that Juul's CEO is warning people against using his e-cigs

Juul now has 15 working days to respond to the FDA and correct the problems identified by the agency.

This is a developing story. Please check back for updates.