Butylated hydroxytoluene

• BPButylated Hydroxytoluene
• JPDibutylhydroxytoluene
• Ph. Eur.Butylhydroxytoluene
• USP–NFButylated Hydroxytoluene

BHT; 2,6-di-tert-butyl-p-cresol; dibutylated hydroxytoluene; butylhydroxytoluenum; Ionol CP; Nipanox BHT; Tenox BHT; Topanol; E321

2,6-Di-tert-butyl-4-methylphenol · [128-37-0]

UNII 1P9D0Z171K · PubChem CID 31404

C15H24O · 220.35

Antioxidant, chelating agent

Typical concentrations: 0.0075–0.1% topical · Dosage forms: Semi-solid

An antioxidant used to delay or prevent oxidative rancidity of fats and oils and loss of activity of oil-soluble vitamins in pharmaceuticals, cosmetics and foods. Typical concentrations are 0.0075–0.1% in topical preparations and about 0.01–0.02% of the fat or oil in oils and foods; low concentrations are also used in some injections and in vitamin A preparations. It is commonly combined with BHA, propyl gallate or citric acid.

White or pale yellow crystals or crystalline powder with a faint characteristic phenolic odour.

Melting point

about 70 °C

Boiling point

about 265 °C

Flash point

about 127 °C (open cup)

Solubility

practically insoluble in water, glycerol, propylene glycol and dilute alkali solutions; freely soluble in acetone, ethanol, methanol, toluene, fixed oils and mineral oil

Exposure to light, moisture and heat causes discolouration and loss of activity. Store in a well-closed container, protected from light, in a cool, dry place.

Incompatible with strong oxidising agents such as peroxides and permanganates, which may cause it to ignite. Iron salts produce discolouration with loss of activity, and heating with catalytic amounts of acid causes rapid decomposition with release of isobutene.

Prepared by reacting p-cresol with isobutene in the presence of an acid catalyst such as sulfuric acid.

Generally regarded as non-toxic and non-irritant at the levels used as an antioxidant, although occasional skin reactions have been reported with topical use. EFSA has set an ADI of 0.25 mg/kg body weight and JECFA an ADI of 0–0.3 mg/kg. Large oral doses are harmful.

Observe normal precautions for the quantity handled. BHT may irritate the eyes and skin; eye protection and gloves are recommended, and dust generation should be minimised.

GRAS listed. Accepted as a food additive in Europe (E321). Included in the FDA Inactive Ingredient Database (oral capsules and tablets, topical, rectal and vaginal preparations, and some injections) and in medicines licensed in Europe.

Butylated hydroxyanisole; propyl gallate; tert-butylhydroquinone; tocopherol.

BHT is less volatile in steam than BHA and is more effective in vegetable oils, while BHA performs better in animal fats; mixtures of the two are therefore common. It is also used to stabilise polymers and packaging materials, from which it may migrate into products.