Nicotine is the addictive substance present in tobacco crops. Benzoic acid can be naturally found in plants, 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 scientific research from 2018 that found that the compounds changed vapers’ sputum—the mucosal lining that covers the internal respiratory tract—to specific totally different immune proteins. Some of those protein adjustments have been linked to asthma. Sign up for our Health Tip of the Day publication, and receive daily ideas that can assist you to live your healthiest life.