BHT (Butylated Hydroxytoluene): Uses and Safety
BHT (butylated hydroxytoluene) is a white crystalline antioxidant that slows oils and fats from going rancid. It is added in small amounts to cosmetics, soaps, oil blends, fuels, rubber and plastics. Typical cosmetic use levels are well under 1%, and it dissolves in oils, not water.
Last updated 7 Nov 2026
Specifications
- Formula
- C15H24O
- CAS number
- 128-37-0
- Grades
- Cosmetic
Products and pack sizes
| Product | Grade | Pack | Price (incl. GST) | ₹ per kg |
|---|---|---|---|---|
| Butylated Hydroxytoluene (BHT) | Cosmetic | — | ₹199 | — |
What is BHT?
BHT, short for butylated hydroxytoluene, is a synthetic antioxidant. It reacts with the free radicals that start rancidity in oils, so oils and products made with them keep their smell and colour for longer. It protects the product, not the skin.
- Chemical name: 2,6-di-tert-butyl-4-methylphenol
- Formula: C15H24O
- CAS number: 128-37-0
- Molar mass: 220.35 g/mol
- Melting point: about 70 °C; boiling point about 265 °C
- Solubility: practically insoluble in water; dissolves in oils and alcohol
Grades and pack sizes at Azlok
Azlok lists BHT in its cosmetic raw ingredients range, for soap makers, lotion and balm makers and small oil-blending units. The pack size is shown on the product page. It is not sold as food grade, so it is not for adding to edible oils or food. See today's price per kg.
Common uses
- Cosmetics and soap: protecting oils in lip balms, body butters, creams, hair oils and cold process soap from going rancid
- Fragrance and oil blends: slowing oxidation of essential oils and fragrance oils
- Industry: antioxidant in fuels, lubricants, rubber, plastics and some adhesives
- Food (food grade only): permitted antioxidant E321 in some foods within set limits
Oils high in polyunsaturated fats, such as sunflower, grapeseed, rosehip and flaxseed, go rancid fastest and gain most from it. Hard butters like cocoa butter are more stable. Rancid oil smells like old crayons or stale namkeen, and in handmade soap it shows up as small orange spots.
How to use it
In cosmetics BHT is typically used at about 0.01 to 0.1% of the formula. For a 1 kg batch, that is 0.1 to 1 g, so you need a scale that reads to 0.01 g.
- Weigh it into the oil phase.
- Warm the oils gently, around 70 °C, and stir until the crystals fully dissolve.
- Carry on with your normal recipe.
BHT only slows rancidity in oils. It does not stop mould or bacteria in water-based products, which need a proper preservative. Add it to fresh oils; it can't undo rancidity that has already started.
Finished cosmetics sold in India need to meet BIS and CDSCO requirements, so if you sell what you make, keep batch records and check the rules that apply to your product.
Safety and storage
- Avoid breathing the dust and avoid eye contact; wear gloves and safety glasses when weighing.
- Keep it away from strong oxidisers.
- Store in a closed container away from heat and light.
- Keep away from children and away from kitchen stores.
- Patch test finished cosmetics on the inner arm for 24 hours before regular use.
Choosing the right grade and pack
Because you use so little per batch, even a small pack lasts home makers a long time. Good BHT is white and free-flowing; yellowed or lumpy material has been exposed to heat or moisture. Buy larger packs only if you run regular batches or blend oils commercially. For food use, buy a food-grade product from an FSSAI-licensed source instead. For 25 kg and more, use the bulk inquiry form.
Frequently asked questions
- How much BHT should I add to lip balm or body butter?
- A typical range is about 0.01 to 0.1% of the total batch, which is 0.1 to 1 g per kg. Dissolve it in the warm oil phase. Use a fine scale, as these amounts are too small to measure by spoon.
- Is BHT a preservative?
- BHT is an antioxidant, not a broad preservative. It slows oils from going rancid but does not stop mould or bacteria. Creams, lotions and anything with water still need a suitable cosmetic preservative.
- What is the difference between BHT and vitamin E for oils?
- Both slow oil rancidity. Vitamin E (tocopherol) is often chosen for label appeal, while BHT is cheaper and effective at very low levels. Some makers use both. Neither replaces a preservative in water-based products.
- Does BHT dissolve in water?
- No. BHT is practically insoluble in water. Dissolve it in oils, butters or alcohol, warming oils to around 70 °C so the crystals melt in fully. In water-based products it has to go in through the oil phase.
- Can I add this BHT to cooking oil?
- No. This pack is a cosmetic raw ingredient and is not labelled food grade. Food use needs a food-grade product used within FSSAI limits. Keep this pack stored away from kitchen items so nobody uses it by mistake.
- How should I store BHT powder?
- Keep BHT in a tightly closed container in a cool, dry place away from sunlight and heat. Close the pack straight after weighing. If the crystals turn yellow or form hard lumps, they have been exposed to heat or moisture.