What Is BHT?
BHT stands for butylated hydroxytoluene, it is a preservative and antioxidant that is used in skincare and cosmetic formulations to stabilize the formulation and prevent oxidation.
BHT is a lipophilic or fat-soluble ingredient that is generally synthetically produced. While BHT is produced naturally by phytoplankton, green algae, and three different types of cyanobacteria, it is more sustainable and cost-effective to synthetically produce the ingredient.
BHT is used in several cosmetic and skincare products, particularly formulations containing oil and fats in a water base. As BHT is an antioxidant it is used to stabilize and protect the key ingredients from deterioration. Unlike many other natural antioxidants, BHT can resist high temperatures, making it useful in the manufacturing process of products as well.
You’ll find BHT primarily in makeup products such as eyeliner, lipstick, blush, and foundation, but you can also find it in various other cosmetic products like moisturizers, cleansers, and perfume. BHT also has applications as an antioxidant in foods that contain fats and oils, or in packaging material for fat-containing foods.
the good:BHT is an antioxidant that helps to stabilize the formulation and reduce contamination of the product through use.
the not so good:While BHT is considered to be safe. There have been some studies that have linked BHT with hormone disruption. However, this link has not been well established.
Who is it for?All skin types except those that have an identified allergy to it.
Synergetic ingredients:Works well with most ingredients including most other antioxidants, helping to boost their effectiveness.
Keep an eye on:More research into this ingredient.
Why Is BHT Used in Skincare?
As an antioxidant, BHT helps fight against the deterioration of cosmetic products caused by free radicals. Oxygen molecules are normally stable and unreactive because they have an even number of electrons. However, when reactions occur that leave the oxygen molecule with an odd number of electrons, the molecule becomes unstable and highly reactive. Since they are highly reactive, they want to either donate that single electron to another molecule or accept an electron from another molecule so that they can become stabilized. This can lead to the degradation of cosmetic products, so ingredients such as BHT are used to maintain product integrity.
In order to combat free radicals, BHT functions as a synthetic analog of vitamin E. Similar to vitamin E, BHT prevents autoxidation. Autoxidation is a process whereby unsaturated organic compounds are attacked by atmospheric oxygen. This can cause changes in color, texture and efficacy of your product. BHT prevents this from occurring.
Why Does BHT Have a Bad Reputation?
BHT is often considered a controversial ingredient. This is because many blogs and skincare articles have presented a link between BHT and cancer. This is a case of misinformation and probably relates to another ingredient, BHA. However, this misinformation has been perpetuated throughout a number of blogs and articles. Studies have actually found that BHT may have a protective ability against cancer in mice. Given that BHT has little to no evidence with being linked to cancer outside of these blogs and skincare articles, BHT is considered to be safe and undeserving of this bad reputation.
Is BHT Safe?
The safety of BHT has been assessed by the Cosmetic Ingredient Review (CIR) Expert Panel. The Cosmetic Ingredient Review Expert Panel is a group responsible for evaluating the safety of skincare and cosmetic ingredients. The Expert Panel reviewed the available data and concluded that BHT was safe for use in cosmetics and skincare products.
The CIR Expert Panel noted that only limited studies evaluated the effects of BHT on skin.
BHT was found to cause effects to the liver and kidneys when taken orally at large doses. This is where the link between BHT and hormone disruption is generally made. However, the Expert Panel argued that this is outside the scope of BHT used in skincare, as the concentrations used in skincare usually range between 0.01 and 0.1%. The FDA considers BHT as Generally Recognized As Safe (GRAS) to use as a food additive up to concentrations of 0.02%. BHT is also not well absorbed through the skin, further mitigating this risk of hormone disruption
BHT is also considered a controversial ingredient because some blogs and skincare articles have presented a link between BHT and cancer. This is a case of misinformation and probably relates to another ingredient, BHA. Studies have actually found that BHT may have a protective ability against cancer in mice. Given that BHT has little to no evidence with being linked to cancer outside of these blogs and skincare articles, BHT is still considered to be safe.
Panico, A, et al., 2019. ‘Skin Safety and Health Prevention: An overview of chemicals in cosmetic products’, Journal of Preventative Medicine and Hygiene, vol. 60, is.1, pp. E50-E57. Lanigan, R & Yamarik, T, 2002. ‘Final report on the safety assessment of BHT’, International Journal of Toxicology, vol. 21, is. 2. Ribeiro, A, Estanqueiro, M, Oliveira, B & Lobo, J, 2015. ‘Main Benefits and Applicability of Plant Extracts in Skin Care Products, Cosmetics, vol. 2, is. 2.