Vitamin E acetate is used in a variety of foods and hygiene items, such as skin creams, and can inhibit lung function when inhaled. It can also be used to bind fluid and make oils thicker, which can then be smoked in e-cigarettes.

This applies especially to oils containing THC, an active ingredient in cannabis.

The fact that the lung damage is likely to be due to vitamin E-actate was found after samples were taken on 29 patients who had damage caused by e-cigarettes.

Anne Schuchat, Deputy Director of the United States CDC, calls the discovery a "breakthrough" and says no other poisons have been found so far in the tests.

The damage is reminiscent of mustard gas

In September, The New England Journal of Medicine published a study by the Mayo Clinic in which it appears that some of the patients have ulcers similar to chemical burns, as reported by the New York Times. The researchers likened the damage to those you get from inhaling mustard gas.

The study was conducted on 17 people, two of whom have died. About 70 percent of them have previously used marijuana or cannabis oil.

Looks like chemical burns

Brandon T. Larsen, one of the doctors behind the study, says the diseased lungs look like "a worker in an industrial accident where a large amount of thin chemicals were spilled and that person was exposed to it and suffered a chemical burn to the lungs."

He goes on to say that the injuries can cause swelling on the lungs and fluid can leak in, which makes it impossible to breathe. According to him, it is not possible to say whether the sick survivors will be fully restored.