The researchers uncovered that PG and PEG400 are more prone to be harmful than natural ingredients like MCT and VG. From The 2, PEG400 was the worst offender; the researchers discovered that it may expose vapers to harmful levels of formaldehyde when it's damaged down in the vape pen. http://cashlsxbf.bloggactif.com/2514693/5-simple-statements-about-cbd-rob-gronkowski-company-explained