Butylated Hydroxy Toluene (BHT) is a synthetic antioxidant that’s used as a preservative (not to be confused with BHA). Even though BHT is not a new ingredient (in cosmetics and food) there is some controversy. Some have proposed it’s a carcinogen but studies have not demonstrated this conclusively and so the research continues. However, the fact is, most studies have focused on high doses that are ingested – which is different from the minuscule amounts used topically.
As for cosmetics, the CIR (Cosmetic Ingredient Review) concluded that the amount of BHT used in cosmetic products is low (usually around 0.01-0.1%), it does not penetrate skin far enough to be absorbed into the bloodstream and it is safe to use in cosmetics.
Related Reading:
- https://www.truthinaging.com/review/what-is-it-bht
- https://incidecoder.com/ingredients/bht
- https://www.paulaschoice.com/ingredient-dictionary/antioxidants/bht.html