Marijuana oils, many illegal or of suspect origin, used in nicotine vaping devices ("e-cigarette" devices) have cause numerous health issues and even deaths recently, and so the U.S.

Environmental Protection Agency has told consumers who are putting marijuana juice into nicotine vaping devices to stop immediately.

To help toxicologists narrow down what is causing these illnesses and deaths, and why so many occurred in a cluster this year, the EPA Computational Toxicology group has published a list of 37 chemicals found in the marijuana plant that give strains their aromatic and flavor profiles. 

These terpenes, Geranyl acetate, Linalool, et al. are now being isolated and concentrated into oils for individual vaping, which means they have to be studied and evaluated individually and in combination to determine what is causing harm. 

People with vaping devices using marijuana oils are again urged to discontinue immediately.