Nov. 8 (UPI) -- Vitamin E acetate, a petroleum-derived oil used in cosmetics, has been named by the government as a "toxicant of concern" in the vaping-related illness outbreak that has killed at least 39 people and sickened more than 2,000.
Researchers pointed to that substance as suspect in a report released Friday in the Center for Disease Control and Prevention's Morbidity and Mortality Weekly Report.
Vitamin E acetate is safe when consumed in foods or used on the skin, but has adverse effects on the lungs when inhaled, scientists said.
The liquid appeared on the illicit THC market this spring, being used as a thickening cutting agent for THC vaping cartridges. It was sold under different names such as "Honey Cut" and "Uber Thick" diluent agent.
"Vitamin E acetate is enormously sticky. You can think of it just like honey," medical officer James Pirkle, of the CDC's Environmental Health Laboratory, said in a media telephone call.
The report analyzed toxic chemicals found in lung fluids from patients suffering from e-cigarette, or vaping, product use-associated lung injury, or EVALI.
In bronchoscopy and bronchoalveolar lavage fluids, researchers found traces of vitamin E acetate in all 29 samples from patients in 10 states with EVALI. Two of the patients died, the agency said.
Researchers used fluid collected during patient treatment from patients using a bronchioscope that squirts a saline solution into the lungs and withdraws a sample of the lining.
Researchers from the CDC's labs also tested for plant oils, other petroleum oils such as mineral oil, medium-chain triglyceride oils and terpenes. They found none of those other substances in lung fluids, the agency said.
Evidence of THC was found in the lung fluids of only 23 of the patients, but researchers said THC does not remain in the lungs.
The national vaping crisis may also be caused by other compounds or substances, said Anne Schuchat, the CDC's principal deputy director. Officials there said more research was needed, and they still advised people to avoid THC vaping cartridges, especially from informal sources such as friends, dealers or online sales.
The Food and Drug Administration is telling people to avoid any vape products until more research has been completed.
Large concentrations of vitamin E acetate first were identified by the New York State Department of Health as being present in THC cartridges used by patients who suffered from the mysterious lung injury.
Earlier, the CDC had said that vitamin E acetate was being used as a cutting agent to expand the profitability of illicit THC vape cartridges, and that internet videos were spreading the strategy.