Nicotine is the addictive substance present in tobacco vegetation. Benzoic acid can also be naturally present in crops, and is used commercially in dyes, perfumes, insect repellants, and meals preservatives. Existing cell, animal, and scientific studies suggest that glycerin and propylene glycol irritate the liner of the lungs. One small clinical research from 2018 that discovered that the compounds changed vapers’ sputum—the mucosal lining that covers the internal respiratory tract—to express totally different immune proteins. Some of those protein adjustments have been linked to bronchial asthma. Sign up for our Health Tip of the Day newsletter, and obtain day by day tips that can assist you to reside your healthiest life.