As lung injuries from vaping have exploded across the country in the last month, the CDC has been scrambling to figure out what exactly is causing the injuries when vaping has long been touted as a safer alternative to smoking. It turns out, many of the injuries may be related to solvents used in black market THC cartridges.

The findings have linked back to vitamin E acetate and myclobutanil, both found in the bootleg cartridges that the CDC tested, but notably not found in the legal and regulated cartridges from dispensaries. Vitamin E acetate is used to cut cannabis for use in vape pens. Myclobutanil, a fungicide, turns into hydrogen cyanide when burned. Testing on patients has also found vitamin E.

Sales of marijuana vape products are down as much as 60% in some states due to the lung illnesses.

Many patients reported using Dank Vape cartridges, and easily accessible, unregulated counterfeit brand. Officials have said there is no specific product or brand that has been linked to the outbreak.

“We are in the midst of a complex investigation that is encompassing nearly all states, and involves serious, life-threatening disease in young health people who have reported the use of a wide variety of substances and products,” said Anne Schuchat, CDC’s principal deputy director.

Kaylee Huntley