What Is Butyl Acetate?
Butyl acetate, also called n-butyl acetate or acetic acid butyl ester, is an ester with the CAS number 123-86-4 and the molecular formula C6H12O2. It is a transparent liquid with a characteristic fruity odour and a typical assay of 99.5 % minimum. Butyl acetate is produced by the esterification of acetic acid with n-butanol. Its primary commercial role is as a fast-evaporating industrial solvent, but a food-grade quality is also accepted in several jurisdictions for use as a synthetic flavouring substance.
Butyl Acetate in Food: Flavour Applications
In the food industry, food-grade butyl acetate is approved for use as a synthetic flavouring agent in regulated quantities. Its fruity odour is used to build artificial fruit flavours, most commonly banana, pineapple, apricot and pear notes. These flavours are incorporated into a wide range of food and drink products, including sweets, cakes, biscuits, soft drinks, ice cream and chewing gum. The substance is used at very low levels to provide aroma, and it is not used as a nutritional ingredient.
Regulatory Status and Grade Selection
Food-grade butyl acetate must comply with food additive specifications, and only material produced and certified for food use may be added to food products. In the United States, n-butyl acetate is listed among synthetic flavouring substances permitted for use in food when used in accordance with good manufacturing practice. Industrial-grade butyl acetate, sold as a solvent for coatings, inks and adhesives, must never be used in food, beverages or flavouring applications. Buyers should verify the grade, the documentation package and the intended end use with their supplier, and follow the maximum permitted levels and labelling requirements that apply in their market.
Key Physical and Chemical Properties
| Property | Value |
|---|---|
| Chemical name | n-Butyl acetate |
| Synonyms | Acetic acid butyl ester |
| CAS number | 123-86-4 |
| Molecular formula | C6H12O2 |
| Molecular weight | 116.16 g/mol |
| Appearance | Transparent liquid, no visible impurities |
| Boiling point | About 126 °C |
| Flash point | About 22 °C |
| Density | About 0.88 g/cm3 |
| Odour | Fruity |
Industrial Solvent Applications
Beyond flavouring, the largest use of butyl acetate is as an industrial solvent. It is widely used in paints, coatings, printing inks and adhesives because of its strong solvency and balanced evaporation rate. The solvent dissolves cellulose esters, vinyl resins and chlorinated rubber, which supports lacquer formulation, and it also appears in cleaning formulations and as an extraction medium for oils and natural products. In all of these uses the appropriate industrial grade is selected, and the material is not intended for human consumption.
Coatings, lacquers and printing inks
Adhesives and artificial leather
Extraction and reaction media
Cleaning and care formulations
Safety and Handling
Butyl acetate is a flammable liquid and should be kept away from heat, sparks and open flames. Its vapour can irritate the eyes and the respiratory tract, so it should be used in well-ventilated areas, with suitable protective gloves and eye protection worn when large quantities are handled. Food-grade flavouring uses involve very small amounts and are strictly controlled by flavouring regulations, while bulk handling of the solvent-grade product requires normal industrial hygiene measures. The current safety data sheet for the specific grade in use should always be consulted before handling.
Frequently Asked Questions
Q: What is butyl acetate used for in food?
Food-grade butyl acetate is used as a synthetic flavouring to create fruit notes such as banana, pineapple, apricot and pear in sweets, cakes, biscuits, soft drinks, ice cream and chewing gum.
Q: Is butyl acetate safe in food?
Food-grade butyl acetate is permitted as a synthetic flavouring in regulated quantities in several jurisdictions, and it must be used in accordance with the applicable food additive specifications and good manufacturing practice.
Q: What is the CAS number of butyl acetate?
The CAS number of butyl acetate is 123-86-4, and its molecular formula is C6H12O2.
Q: Can industrial butyl acetate be used in food?
No. Industrial-grade butyl acetate sold as a solvent must never be used in food, beverages or flavouring applications; only certified food-grade material is permitted.
Q: Why does butyl acetate smell fruity?
Butyl acetate is an ester, and esters typically have pleasant fruity odours. This characteristic is the basis for its use in artificial fruit flavour formulations.
Q: What is the main industrial use of butyl acetate?
The main industrial use of butyl acetate is as a solvent in paints, coatings, printing inks and adhesives, where its strong solvency and moderate evaporation rate are valued.