BHT aka butylated hydroxytoluene. BHT is an antioxidant often used to preserve skincare products, usually in a concentration ranging from 0.0002% to 0.5%.
Why use BHT in skincare
Free radicals are highly reactive molecules with unpaired electrons that are known to damage various cellular structural membranes, lipids, proteins, and DNA. It is one of the widely accepted mechanisms that lead to skin ageing. The body can be exposed to free radicals from environmental exposures (as well as intrinsic exposures), such as cigarette smoke, air pollution, and ultraviolet radiation from the sun. In addition, free radicals can easily degrade skincare products, rendering them ineffective. This is where antioxidants come in handy – they aim to protect cells or skincare products from the damaging effects of free radicals.
BHT is a popular antioxidant used in skincare products. When skincare products are exposed to free radicals (through the air or UV radiation) this can lead to their degradation. To quench these free radicals or stop them forming, BHT is often incorporated into skincare products. BHT isn’t an active component of the skincare product itself, but rather one that protects the active ingredients from free radicals so that they can do their job as intended.
Is BHT safe?
As helpful as BHT is in preserving our skincare products, it is however, under investigation due to concerns regarding its safety. BHT is accused of being an endocrine disruptor (natural or man-made chemicals that may mimic or interfere with the body’s hormones, potentially having a negative effect) but it is still frequently used in skincare formulations.
The toxicity accusations concerned with BHT come generally from oral toxicity studies, whereby animals ingested significant quantities. However, studies show that when BHT is applied to the skin topically as part of a skincare formulation (ranging from 0.0002-0.5%) that the antioxidant penetrates the skin, but the relatively low amount absorbed remains primarily in the skin. This study found that the total amount that penetrated the skin was 0.07% of the applied dose.
Overall outlook – should I use products containing BHT?
Animal or human studies evaluating the effects of BHT on skin are limited and as a result, the topic of whether BHT is safe in skincare products remains controversial. However, whilst we know that dermal application of BHT results in some absorption into the skin, it appears to remain primarily in the skin and does not produce systemic exposures to BHT (or its metabolites) of the magnitude seen in oral studies. In addition, the European Union’s Scientific Committee on Consumer Safety concluded in December 2021 “On the basis of a safety assessment, and considering the concerns related to potential endocrine disrupting properties of BHT, the SCCS is of the opinion that BHT is safe as an ingredient up to a maximum concentration of 0.8% in other leave-on and rinse-off products.”
In light of this, we’d recommend not to steer away from an A-game product just because of the presence of BHT. Top products often perform so well because of their formulation, and that includes making sure the formulation is resistant to free radicals so that it can perform at its best for longer.
For more on whether a chemical can be determined as safe (or non-safe) visit: https://insidemyproducts.com/natural-beauty-products/
Lanigan, R. S., & Yamarik, T. A. (2002). Final report on the safety assessment of BHT(1). International journal of toxicology, 21 Suppl 2, 19–94.
Martiniaková,S.,Ácsová,A.,Hojerová,J.,Krepsová,Z. & Kreps,F.(2022).Ceylon cinnamon and clove essential oils as promising free radical scavengers for skin care products. Acta Chimica Slovaca,15(1) 1-11.
Ghosh, C., Singh, V., Grandy, J., & Pawliszyn, J. (2020). Development and validation of a headspace needle-trap method for rapid quantitative estimation of butylated hydroxytoluene from cosmetics by hand-portable GC-MS. RSC Advances, 10(11), 6671-6677.