Butylated Hydroxytoluene (BHT, E321)
BHT is a synthetic antioxidant that delays products containing fats from being spoiled by oxygen and going rancid. It is used at very low levels in cosmetics and within permitted limits in food. It is considered of less concern than its close relative BHA; even so, regulators continue to monitor it.
Risk range
1 is the lowest and 10 the highest risk. The range depends on the amount used, whether the product is rinsed off and how it is used. The Temiz İçerik app uses the same ranges.
In cosmetics it is usually used at well below one part in a thousand; the lower end is for rinse-off products, the upper end for products with long contact, such as lip and face products.
In food, the upper end is set by the fact that BHT can be taken in from several frequently eaten processed products together (crisps, chewing gum, instant soup).
What is BHT and what is it used for?
Butylated hydroxytoluene is a synthetic antioxidant with a phenolic structure. When fats and fat-soluble substances react with oxygen in the air, they go rancid and their smell and colour deteriorate. BHT slows this chain reaction of oxidation, extending the product's shelf life.
Being an antioxidant does not mean BHT is a skin “care” ingredient; its job is to protect the product itself. This is why it usually appears near the end of the label, among the ingredients present at low levels.
Which products contain it?
- Oil-based cosmetics such as lipstick, lip balm, foundation and eye make-up
- Moisturising creams, sun products and perfumes
- Chewing gum, crisps, instant soup, breakfast cereals and some fats (as E321)
- As an additive in food packaging and some plastics
Is it harmful? The scientific assessment
The European Food Safety Authority (EFSA) re-evaluated BHT and set an acceptable daily intake (ADI), reporting that this limit is not expected to be exceeded with a normal diet. Turkish food additive legislation is aligned with the EU; E321 may be used only in permitted foods and up to set amounts.
On the cosmetics side, the SCCS, the EU's scientific committee, found BHT safe within certain concentration limits; following this, the EU introduced maximum limits according to the type of cosmetic product. Effects on the liver and thyroid have been seen in high-dose animal experiments; however, these doses are far above the amounts taken in from products.
BHT is not classified by IARC as carcinogenic to humans (Group 3: not classifiable). Possible effects on the hormone system are being studied; at present, no clear risk has been shown for consumer use.
The difference between BHT and BHA
The two substances do the same job and are often mentioned together. However, while BHA has been classified by IARC in Group 2B (possibly carcinogenic to humans), there is no such classification for BHT. This is why the app rates BHT in a lower risk range.
Who should be careful?
- People sensitive to antioxidant additives: Skin redness or itching has been reported very rarely.
- People who eat processed food very often: The overall nutritional value of these products matters more than the BHT itself; variety reduces the risk.
- Young children: Because they can take in more additives relative to their body weight, limiting processed snacks is generally recommended.
What to do when you see it on a label
If a cosmetic or food containing BHT has been produced in line with the regulations, there is no strong reason for concern. If you would like a more natural option, you can choose products preserved with antioxidants such as tocopherol (vitamin E), rosemary extract or ascorbic acid.
Frequently asked questions
Does BHT cause cancer?
BHT is not classified by IARC as carcinogenic to humans. The carcinogenicity debate relates mainly to its relative BHA.
Is E321 halal or vegan?
BHT is produced synthetically and is not of animal origin. However, whether the product as a whole is suitable depends on its other ingredients.
Is it safe to use lipstick containing BHT?
It is considered safe when used within the limits set in the EU for lip products. If your lips become irritated, simply switching products is enough.
Sources
Updated: 2026-10-11 · How we score
This page is for general information and is not personal medical advice. Warnings on the product label and the advice of a health professional always come first.