Introduction

Iso-amyl alcohol (3-Methyl-1-butanol; 3MB) is a clear, colourless alcohol with formula C5H12O. It is one of several isomers of amyl alcohol. Less dense than water, soluble in water. Hence, it floats on water. Produces an irritating vapor. Isoamyl alcohol is a natural product found in Ambrosiozyma monospora, Humulus lupulus, and other organisms with data available.

Uses

3MB is the primary constituent of the fusel oil (by-product of alcoholic carbohydrate fermentation). It is mainly used to manufacture photographic chemicals, pharmaceutical products, decorative cosmetics (shampoos, toilet soaps, etc.), and non-cosmetic products such as household cleaners and detergents. It also serves as a solvent for oil, fats, resins, and waxes, as a component of paint strippers and used in the plastic industry. In addition, 3MB is used as an intermediate of fragrance and herbicides. 3MB is also found in fruit, wine, and beer[1].

3-Methyl-1-butanol is one of the commonly reported Microbial volatile organic compounds (MVOCs) in buildings with moisture and microbial damage and occupational settings related to agriculture and composting. 3MB showed a weak but statistically significant correlation with mold status in a study by Schleibinger et al. (2008). It is one of the compounds described as an indicator of mold growth. The levels of 0.38–0.69 lg/m3 3MB, depending on house characteristics (e.g., structure and age of the house, renovation), have been measured indoors in family homes. In schools in Sweden (23 classrooms), the levels of 95 ng/m3 3MB (range < 1–560) have been reported.

Toxicity

Slight throat irritation was reported in human volunteers exposed to 3MB at 100 ppm for 3–5 min. Ocular and upper respiratory tract irritation was noted following exposure at 150 ppm. Irritation of the throat was also reported in a respiratory uptake study, in which volunteers were exposed through a mouthpiece to about 92 mg/m3 (25 ppm) for 10 min.