BHT

Good

Antioxidant

No known benefits

BHT at a glance

  • The abbreviation for butylated hydroxytoluene 
  • Potent synthetic antioxidant 
  • Helps keep delicate ingredients stable 
  • Considered safe as used in cosmetics

BHT description

BHT is Butylated hydroxytoluene, a potent synthetic antioxidant sometimes used to help stabilise light- and air-sensitive cosmetic ingredients such as retinol and unsaturated fatty acids. BHT is also globally approved for use as a food-grade preservative, where its antioxidant action keeps foods fresher longer. Amounts of 0.02% or less are considered safe for this use; however, controversial reports have been published since the 1970s that digestive metabolites of BHT could cause health problems. The amount of BHT uses in cosmetic products is typically 0.0002%-0.5%. Such low amounts do not pose a risk to skin (indeed, the safety assessment found BHT was non-irritating) nor does it penetrate skin far enough to be absorbed into the bloodstream. The European Union’s Scientific Committee on Consumer Safety concluded in December 2021 that “BHT is safe as an ingredient up to a maximum concentration of 0.8% in other leave-on and rinse-off products.”

BHT references

  • Environmental Science and Technology, October 2020, pages 11,706–11,719
  • Environment International, July 2019, pages 24–29
  • International Journal of Toxicology, Volume 21, Issue 2, October 2002, pages 19–94
  • https://ec.europa.eu/health/sites/default/files/scientific_committees/consumer_safety/docs/sccs_o_257.pdf

Peer-reviewed, substantiated scientific research is used to assess ingredients in this dictionary. Regulations regarding constraints, permitted concentration levels and availability vary by country and region.

Ingredient ratings

Best

Proven and supported by independent studies. Outstanding active ingredient for most skin types or concerns.

Good

Necessary to improve a formula's texture, stability, or penetration.

Average

Generally non-irritating but may have aesthetic, stability, or other issues that limit its usefulness.

Bad

There is a likelihood of irritation. Risk increases when combined with other problematic ingredients.

Worst

May cause irritation, inflammation, dryness, etc. May offer benefit in some capability but overall, proven to do more harm than good.

unknown

We couldn't find this in our ingredient dictionary. We log all missing ingredients and make continuous updates.

Not rated

We have not yet rated this ingredient because we have not had a chance to review the research on it.