Nicotine is the addictive substance found in tobacco vegetation. Benzoic acid can be naturally present in plants, and is used commercially in dyes, perfumes, insect repellants, and meals preservatives. Existing cell, animal, and scientific studies counsel that glycerin and propylene glycol irritate the lining of the lungs. One small medical study from 2018 that discovered that the compounds modified vapers’ sputum—the mucosal lining that covers the internal respiratory tract—to precise totally different immune proteins. Some of those protein modifications have been linked to asthma. Sign up for our Health Tip of the Day newsletter, and receive day by day ideas that can help you reside your healthiest life.