Are BHA and BHT in Cosmetics Safe? What You Should Know About These Antioxidants

What Are BHA and BHT?

BHA (Butylated Hydroxyanisole) and BHT (Butylated Hydroxytoluene) are synthetic antioxidants used widely in both the food industry (E320, E321) and in cosmetics. In cosmetic formulations they act as stabilisers — they slow the oxidation of active ingredients, fats and oils, significantly extending a product's shelf life.

You'll find them in body creams and lotions, makeup products, shampoos, and even crisps and other foods. Their ubiquity in both diet and cosmetics means that a consumer's combined exposure to these substances is considerable — and it is precisely this aspect that draws the greatest interest from researchers.

You can browse the full list of products containing BHA and BHT in the PurScore ingredient database.

BHA and BHT — Regulatory Status in the EU

In the European Union, both ingredients are permitted for use in cosmetics under Regulation (EC) No 1223/2009. They appear in Annex III (substances subject to restrictions). BHA and BHT may be used as antioxidants, with restrictions covering specific product categories and concentrations.

The SCCS has assessed both ingredients on numerous occasions. Recent opinions indicate that BHT is safe at the concentrations currently used in cosmetics. BHA is evaluated more cautiously — in 2021 the European Commission classified BHA as a potential endocrine disruptor (category 1 on the list of EDC candidate substances for regulation). This is an important signal, although being added to the list does not in itself mean an immediate ban.

BHT — What Does the Research Say?

BHT has been the subject of hundreds of studies over the past 50 years. The findings are mixed:

• Protective action — Some studies suggest BHT may act as an antioxidant and have protective properties for cells. In animal studies, potential anti-cancer effects have been observed in certain experimental models.
• Carcinogenic action? — Other studies in rodents have shown the promotion of certain tumours at very high, long-term doses. The IARC has classified BHT as not classifiable as to its carcinogenicity to humans (Group 3).
• Skin penetration — BHT shows the capacity for transdermal absorption, although lower than that of many UV filters. BHT metabolites are detectable in urine.
• Hormonal activity — Individual studies have suggested weak oestrogenic activity for BHT. The data are less consistent than for BHA.

BHA — More Serious Concerns

BHA raises somewhat greater concern than BHT. Toxicological data point to:

• Endocrine activity — BHA interferes with sex hormone receptors in in vitro and in vivo studies. It is precisely this mechanism that lay behind the EDC classification in the EU.
• Irritant effects — Higher concentrations of BHA can cause skin and eye irritation.
• Carcinogenicity — The International Agency for Research on Cancer (IARC) has classified BHA in Group 2B (possibly carcinogenic to humans) — the same category as, for example, whole-leaf aloe extract or certain nickel compounds, which requires context when interpreting it.

The key distinction here, however, is this: the IARC classification and other assessments are based largely on studies using doses significantly higher than the realistic exposure of a consumer using cosmetics. In body lotions, BHA is used at concentrations in the order of 0.01-0.1%.

Browse body lotions on PurScore is easily filter for products free from BHA or BHT.

Cumulative Exposure — An Often Overlooked Aspect

One of the challenges in assessing BHA and BHT is combined exposure: the same substances are found in food, packaging and cosmetics. Once we add dietary intake, the exposure level can be significantly higher than would follow from analysing cosmetics alone. EU regulations assess each product category separately — there is no systematic assessment of the cumulative risk across food and cosmetics.

Who Should Avoid BHA and BHT?

• People with sensitive or reactive skin — BHT and BHA can cause irritation.
• People applying the precautionary principle towards potential endocrine-disrupting substances — particularly with regard to BHA.
• Pregnant women who prefer to minimise exposure to EDC ingredients.
• Children — because of their lower body weight, the same ingredient concentration results in relatively higher exposure.

The information in this article is educational in nature and does not constitute medical advice. If you have health concerns, consult a doctor or dermatologist.

Alternatives — Without BHA and BHT

Natural and synthetic alternative antioxidants include vitamin E (tocopherol), vitamin C (ascorbic acid), rosemary extract (Rosmarinus Officinalis Extract) and astaxanthin. Products using these ingredients as stabilisers are available on the market and increasingly popular in the "clean beauty" segment. You'll find rundowns of products free from BHA and BHT in the PurScore best-products section.

Summary: BHA and BHT in Cosmetics

BHT in cosmetics, at the concentrations used by the industry, is considered safe by the SCCS. BHA warrants caution because of its EDC classification in the EU and the data on potential hormonal activity. Neither of these ingredients is banned, but the informed consumer has the right — and the means — to choose products without these substances. The key is reading ingredient lists and using tools to analyse them.

Check the ingredients in your cosmetic →