Technical Specifications
| Property | Unit | Typical Value | Test Method |
|---|---|---|---|
| Appearance | Colorless crystalline particles | Visual | |
| Melting Point | °C | 75 | ASTM E324-23 |
| Purity | % | 99.9 | GC |
* Typical values from batch production. Batch-specific COA available on request.
Technical content reviewed by the CheMost additives team · Specifications last reviewed
Molecular Structure
Molecular structure · hindered phenol
C₁₅H₂₄O (MW 220.35)
2,6-Di-tert-butyl-4-methylphenol — a hindered phenolic primary antioxidant; the two tert-butyl groups shield the –OH that scavenges radicals.
What Is Butylated Hydroxytoluene (BHT)?
CheMost-BHT is 2,6-di-tert-butyl-4-methylphenol — the classic hindered-phenolic antioxidant, supplied as 99.9%-pure colourless crystalline granules. Widely known by the abbreviation BHT (and by the Chinese trade synonym T501), it is an oil-soluble free-radical scavenger that slows the oxidative ageing of lubricants, fuels and greases before it reaches a critical stage.
BHT is a primary antioxidant: the phenolic –OH, shielded by two bulky tert-butyl groups, donates a hydrogen atom to a propagating peroxy radical, halting the oxidation chain. It is the textbook example of the mechanism — a small, single-molecule phenol that is inexpensive, effective and easy to source, which is why it remains the baseline antioxidant across countless formulations.
Its limitation is temperature. Being a small molecule, BHT is relatively volatile and, in very hot service, its intermediates break down and it loses effectiveness. So BHT is the cost-effective choice for low-to-moderate-temperature oils; for hotter or longer-drain duty, formulators step up to a high-molecular-weight phenol (AO135) or an aminic antioxidant (AO57). Where a pourable phenol is wanted, the liquid blend AO52 is the BHT-based alternative.
How BHT Works
Hydrogen donation
The hindered phenolic –OH donates a hydrogen atom to a peroxy radical, converting the radical to a stable hydroperoxide and stopping it from propagating the oxidation chain.
Stable phenoxy radical
The two tert-butyl groups sterically stabilise the resulting phenoxy radical, so it does not itself start new chains; two phenoxy radicals can terminate together, regenerating one BHT molecule.
Broad, low-cost protection
At 99.9% purity and low cost, BHT delivers reliable baseline oxidation protection across a very wide range of lubricants, fuels and greases.
Temperature ceiling
As a small, volatile molecule its intermediates decompose under high heat, so BHT is best in low-to-moderate-temperature service; hotter duty calls for a high-MW phenol or an aminic.
Antioxidant Types Compared — Where BHT Fits
Lubricant antioxidants split into aminic and phenolic primary types plus liquid/solid forms. The table places BHT against CheMost’s other antioxidant grades so you can pick by temperature, form and cost. All figures are from each grade’s data sheet.
| Grade | Class | Form | Key spec | Temperature niche |
|---|---|---|---|---|
| BHT (this page) | Phenolic (simple) | Solid | Purity 99.9% | Low–moderate temperature |
| AO52 | Phenolic (mixed blend) | Liquid | Free phenol 0.5% | Low-end industrial / turbine |
| AO135 | Phenolic ester (HMW) | Liquid | 100% active | High-temp, low-volatility |
| AO57 | Aminic (alkylated diphenylamine) | Liquid | N 4.58% · TBN 198 | High-temperature primary AO |
BHT is the lowest-cost entry point. If solid handling is unwanted, the liquid blend AO52 delivers comparable phenolic protection in pourable form; for high temperature, move up to AO135 or AO57.
Applications
CheMost-BHT is used as the baseline phenolic antioxidant in formulations targeting the duties below:
Industrial & hydraulic oils
Cost-effective oxidation protection for general industrial, hydraulic and circulating oils running at low-to-moderate temperature.
Turbine oils
Baseline antioxidancy for turbine and other long-life industrial oils, often alongside an aminic for added high-temperature reserve.
Greases & specialty fluids
Oxidation protection for greases and specialty lubricants, where its solubility and low cost make it a workhorse antioxidant.
Finished-oil performance approvals belong to the fully formulated oil, not to an individual antioxidant component.
Treat Rate
The data sheet specifies the product but not a per-application dosage, so the figures below are indicative, derived from the chemistry and our formulating experience — confirm the final level.
First-order estimate. As a phenolic primary antioxidant, BHT is used at roughly 0.05–1% (commonly 0.1–0.5%), dosed to the oxidation target. Being solid, it is dissolved into the blend (maximum blending temperature 70 °C per the data sheet) before the rest of the package is added.
BHT is frequently combined with an aminic antioxidant such as AO57 (heterosynergism) so the pair covers a wider temperature range than BHT alone. Where the solid form is inconvenient, the liquid blend AO52 doses the same phenolic chemistry without melting. The exact level depends on the oxidation target, the base oil and the rest of the package.
Treat rates are indicative, not fixed dosages. CheMost can provide formulation and treat-rate support on request.
Formulating With BHT — Complementary Additives
Aminic antioxidant (AO57)
Pairing the phenolic BHT with an aminic gives heterosynergism — two radical-trapping mechanisms that regenerate one another and extend protection to higher temperature than BHT reaches alone.
ZDDP
ZDDP is a secondary antioxidant — it decomposes the peroxides that BHT’s radical-trapping leaves behind — and adds antiwear protection.
Metal deactivator (BTA)
Copper accelerates oxidation; a metal deactivator such as benzotriazole passivates yellow metals so the BHT is not consumed fighting metal-catalysed degradation.
High-MW phenolic (AO135)
For hot or long-drain service where BHT volatilises, a high-molecular-weight phenol such as AO135 supplements or replaces it while keeping the same phenolic mechanism.
Documentation, Qualification & Regulatory Support
Standard documentation — Certificate of Analysis (COA, per shipment), Technical Data Sheet (TDS) and Safety Data Sheet (SDS, GHS/CLP) — is provided. The full TDS is available on request rather than as a public download. Additional support is available on request:
Regulatory documentation
REACH, TSCA and country-specific market-registration documentation support available on request.
Third-party inspection
SGS / Intertek / BV pre-shipment inspection can be arranged on request.
Custom grades & packaging
Custom packaging and grades on request.
Formulation support
Antioxidant-system and treat-rate guidance from our technical team.
Packaging & Supply
CheMost-BHT is stocked and shipped worldwide, with a typical lead time of 1–15 days and a 36-month shelf life at ambient temperature. Samples and quotations are answered within 12 hours.
Packaging
25 kg bag (crystalline granules).
Minimum order
By bag or pallet — contact us for your quantity.
Incoterms
FOB · CIF · EXW, to suit your freight arrangement.
Loading ports
All major Chinese ports.
Frequently Asked Questions
What is butylated hydroxytoluene (BHT)?
BHT is 2,6-di-tert-butyl-4-methylphenol (CAS 128-37-0), a hindered phenolic primary antioxidant supplied as 99.9%-pure crystalline granules. The phenolic –OH scavenges free radicals to slow oxidative ageing in lubricants, fuels and greases. It is also known by the trade synonym T501.
Is BHT the same as T501?
Yes — T501 is a common Chinese-standard trade synonym for the same chemical, 2,6-di-tert-butyl-4-methylphenol. CheMost describes the product by its international chemical name (BHT) and supplies it to that specification.
When should I choose a different antioxidant?
BHT is the cost-effective baseline for low-to-moderate-temperature service. For hot or long-drain duty where BHT volatilises, use the high-molecular-weight phenol AO135 or the aminic AO57. If you want phenolic protection in pourable liquid form, use the blend AO52.
What treat rate should I use?
BHT in lubricants is typically used at about 0.05–1% (often 0.1–0.5%), dosed to the oxidation target. As a solid it is dissolved into the blend (max blending temperature 70 °C). The exact level depends on the base oil and the rest of the package; our technical team can assist.
How is it supplied, and how fast can I get a sample?
It is supplied as colourless crystalline granules in 25 kg bags with a 36-month shelf life, and shipped worldwide. As a manufacturer and sourcing partner (Est. 2013), CheMost answers sample and quotation requests within 12 hours.