B.H.T. (butylated hydroxytoluene)

BHT (Butylated Hydroxytoluene) is a widely used ingredient in perfumery and cosmetic formulations, valued primarily for its role as a powerful antioxidant and stabilizer rather than for its odour, which is very faint, slightly phenolic, and practically negligible in finished compositions.

The material typically appears as a white crystalline solid, and is highly effective at preventing oxidation of fragrance materials, especially those prone to degradation such as citrus oils, aldehydes, and unsaturated compounds. By inhibiting oxidation, BHT helps maintain the original scent profile, color, and overall quality of a formulation over time.

In practical perfumery, BHT is used in very small concentrations, as its function is purely technical:

• In fragrance concentrates (perfume oils): typically around 0.01% – 0.1%

• In finished products (e.g., alcohol-based perfumes, cosmetics): usually 0.001% – 0.01% depending on the formula

• In systems containing highly oxidation-sensitive materials (especially citrus-heavy compositions), usage may be adjusted slightly within safe limits to ensure stability

It is generally added during the formulation stage, often dissolved in a small portion of solvent (such as ethanol or DPG) to ensure uniform distribution throughout the composition.

BHT is especially important in formulas where long shelf life, color stability, and resistance to air and light exposure are critical. It works synergistically with other stabilizing strategies such as proper storage, use of UV absorbers, and airtight packaging.

Because of its neutral odour and high efficiency, BHT has become a standard technical component in many fragrance systems, ensuring that the perfume remains stable, consistent, and true to its intended profile over time.