“These findings provide direct evidence of vitamin E acetate at the primary site of injury within the lungs,” said Anne Schuchat, principal deputy director at the Centers for Disease Control and Prevention. The latest findings point to growing evidence of vitamin E acetate as “a very strong culprit of concern,” she said.
The findings announced Friday do not rule out other possible compounds or ingredients that may be causing the lung injuries. But Schuchat described the lab results as a “breakthrough” in the investigation. CDC tested for a wide range of substances that might be found in patients’ lung fluids, including plant oils and petroleum distillates, such as mineral oil.
But, she said, “No other potential toxins were detected.”
CDC officials found vitamin E acetate, an oil derived from the vitamin, in all 29 samples of lung fluid collected from patients who had fallen ill or died from lung injuries. THC, the psychoactive ingredient in marijuana, was also found in 23 patients, including three who said they had not used THC products. Nicotine was detected in 16 of 26 patients. Most patients who have fallen ill in the outbreak have vaped THC, officials have said.
Vitamin E acetate, an oil derived from the vitamin, has already been identified in previous testing by federal and state laboratories in vape products that contain THC. Many of those products were obtained on the illicit market, officials have said. Vitamin E acetate has been used in recent months as a cutting agent or additive on the cannabis black market to stretch the amount of THC in vape cartridges, officials and industry experts have said. Vitamin E acetate is a popular additive because it is colorless and odorless, has similar viscosity to THC oil and is much cheaper.
The findings are significant because for the first time, scientists have been able to connect results from product testing with clinical specimens from patients, she said. The 29 patients are from 10 states, representing a diverse geographical area, making the findings “much more robust” than if all the patients were from a single location.
“They help us better understand the potential compounds” that may contribute to the injuries, Schuchat said. “They tell us what entered the lungs of some of these patients.”
Vitamin E acetate is found in many foods and in cosmetics, especially skin care products. It’s not known to cause harm when swallowed or applied to the skin, Schuchat said. But when it is heated and inhaled, it may interfere with normal lung function. Its properties could be associated with the kinds of respiratory symptoms that many patients have reported: cough, shortness of breath and chest pain, officials and experts have said.
Chemistry professor Michelle Francl has described vitamin E acetate as basically grease. Its molecular structure means that “you have to heat it up pretty hot” for it to vaporize, said Francl, a professor at Bryn Mawr College. The substance’s boiling point is 363 degrees Fahrenheit, which is well above the 212 degrees F boiling point for water.
Once the oil is heated enough to vaporize, it can potentially decompose, and “now you’re breathing in who-knows-what,” Francl has said.
But officials still need to conduct more testing of the substance, including in other people who vaped and who did not experience these injuries, Schuchat said. Officials also want to test a broader number of lung fluid samples from patients in different locations, she said.
Animal studies also need to be undertaken to better understand how vitamin E acetate might cause the disease to develop, she said.
The findings, which were also detailed in a CDC report released Friday, also reinforced health official warnings against using e-cigarette or vaping products that contain THC, especially those bought off the street.
CDC is maintaining its recommendation that consumers consider refraining from using all vaping and e-cigarette products, including those containing nicotine. That’s because a small proportion of patients continue to report exclusive use of nicotine-containing products, Schuchat said.