Popular e-cigarette company Juul is facing a fine or even seizure of its products after federal health officials said the companys advertising violated federal regulations.

The Food and Drug Administration, in a warning letter issued to Juul Labs on Monday, declared that the company unlawfully branded its products as a safer alternative to cigarettes without gaining the FDAs approval. It also targeted children.

Regardless of where products like e-cigarettes fall on the continuum of tobacco product risk, the law is clear that, before marketing tobacco products for reduced risk, companies must demonstrate with scientific evidence that their specific product does in fact pose less risk or is less harmful, Acting FDA commissioner Ned Sharpless said in a statement.