What is EVALI?

The outbreak peaked at more than 200 new cases a week in September 2019. Patients presented with cough, shortness of breath, chest pain, fever and gastrointestinal symptoms, and many required intensive care and mechanical ventilation. The median age was 24, two thirds were male, and 15 percent were under 18.

The cause was identified rather than guessed at. Vitamin E acetate — an oily compound used as a cheap thickening diluent to make illicit THC cartridges look and pour like higher-quality product — was found in product samples tested by the FDA and state laboratories, and in the lung fluid of EVALI patients from geographically diverse states. It was not found in the lung fluid of people without the condition.

The products involved were overwhelmingly THC-containing cartridges obtained from informal sources: friends, family, in-person dealers and online sellers. Nicotine vaping products from the regulated retail market were not the driver.

This distinction is the single most misreported thing about EVALI. It is routinely cited as evidence that nicotine vaping causes lung disease, and that is not what the investigation found. It was a contamination event in an unregulated illicit supply chain, and case numbers fell sharply once vitamin E acetate was publicized and removed from that supply.

The useful lesson is narrower and still relevant: the danger sat in the unregulated supply rather than in the act of vaping as such. That applies directly today to any THC or delta-8 cartridge from an informal source, where no one has verified what the diluent is — and to nicotine products that lack FDA authorization, whose composition no regulator has examined.

EVALI has not disappeared entirely. Sporadic cases continue to be reported, which is consistent with an illicit supply chain that was never fully cleaned up rather than eliminated.