The recent outbreak of vaping-related lung illness shows no sign of letting up. A recent report by the Centers for Disease Control and Prevention (CDC) has linked at least 12 deaths and 805 cases of acute lung damage to the use of cannabis or nicotine vapes. Health officials have proposed that Vitamin E additives could be responsible for this illness, but a new investigation is implicating that it’s myclobutanil, an illegal pesticide often used by black market weed growers.

The CDC reports that most of the individuals suffering from this illness have reported using cannabis vapes. Preliminary investigations have also linked many of these cases specifically to black market THC pens. To test the theory that illegally-produced cannabis vapes could be responsible for the crisis, NBC News purchased 15 black market vapes and 3 legal vapes and handed them over to CannaSafe, one of the country’s leading marijuana testing facilities.

Out of the fifteen black market vapes, 13 were found to contain Vitamin E acetate, the potentially deadly additive that’s previously been linked to this illness. But CannaSafe also tested ten of the black market cartridges for pesticides, and found that every single one of them was tainted with myclobutanil — a fungicide that releases hydrogen cyanide gas when burned or heated.

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“You certainly don’t want to be smoking cyanide,” said Antonio Frazier, vice president of operations at CannaSafe, to NBC. “I don’t think anyone would buy a cart that was labeled ‘hydrogen cyanide’ on it.” 

Dr. Melodi Pirzada, pediatric pulmonologist at NYU Winthrop Hospital in Mineola, New York, told NBC that myclobutanil contamination can “cause a very toxic effect on the lungs.” Pirzada was also concerned about the presence of Vitamin E, which can cause significant lung damage if inhaled.

CannaSafe also tested three vape carts purchased from licensed California cannabis stores, and found these products to be free of myclobutanil, Vitamin E, or other toxins. Like most other adult-use states, California imposes strict testing regulations on all legal weed products to ensure that they are free from toxins and contaminants. Illegal vape manufacturers often buy untested vape carts and additives from China, which could be contaminated with pesticides, solvents, and heavy metals.

Acting FDA Commissioner Ned Sharpless told a Congressional committee that his agency is working to identify where these toxic products are originating from. “FDA is not pursuing any actions associated with personal use of any vaping products, our interest is in the suppliers,” Sharpless said, NBC reports. “But to be clear, if we determine that someone is manufacturing or distributing illicit, adulterated vaping products that caused illness and death for personal profit, we would consider that to be a criminal act.”

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