Federal health authorities think they’ve identified a potential culprit for the vaping illness that’s sickened thousands of people across the country.

The head of the Centers for Disease Control and Prevention, Dr. Ann Schuchat, said Friday their labs found vitamin E acetate in all samples taken from 29 patients across 10 states.

“These new findings are significant because for the first time we have detected a potential toxic of concern, vitamin E acetate, in biologic samples,” Schuchat said.

She has not ruled out other chemicals as possible causes for the illness. For example, nicotine and the psychoactive ingredient in cannabis were found in many of the cases in the lab.

The Oregon Health Authority welcomed the new evidence but still recommends people not vape.

Vitamin E acetate is sometimes used to thicken the liquid in a vaping pen so it can be vaporized more efficiently.

This discovery comes after more than 2,000 people have been sickened and 39 killed, including two people in Oregon.