Green Biologics nC4-OL (Renewable n-butanol)

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What is nC4-OL?

Green Biologics nC4-OL is a 100% bio-based, high purity n-butyl alcohol that is produced from fermentation of sugars by Green Biologics’ proprietary Clostridium microbial biocatalysts. Green Biologics nC4-OL is derived from renewable resources compared to traditional petrochemical-based n-butanol, which is made through a multi-step process starting from petroleum-derived propene. Green Biologics nC4-OL is selectively produced by bacteria as opposed to a multi-step process from crude petroleum distillates resulting in a higher purity product with no aldehydes and significantly lower iso-butanol. While Green Biologics nC4-OL is of higher purity and quality, the molecule is identical to n-butanol produced from petroleum feedstocks, allowing for direct ‘drop-in’ to existing applications and formulations.

n-butanol Basics

n-butanol (normal n-butanol or butyl alcohol) is a four-carbon alcohol that is a clear, colorless, flammable and neutral liquid with a characteristic banana-like odor. The medium volatility and restricted miscibility in water of n-butanol make it useful as both a solvent and a formulated ingredient in cosmetic and personal care products.


The robust solvent properties of n-butanol make it a versatile oxo-chemical with several direct applications. Additionally, n-butanol is a valuable feedstock for production of higher value chemicals, chiefly ethers and esters. Aside from its use as a solvent, alcohol plasticizer, and additive in formulated consumer products, n-butanol is commonly used for the manufacturing of esters utilized for fragrance, skincare and haircare products. Cosmetic products that utilize n-butanol in their formulations include eye makeup, foundations, lipsticks, nail care products, personal hygiene products, shaving creams, and moisturizers.

Health and Toxicity

Like the ubiquitous two-carbon alcohol ethanol, n-butanol is a relatively safe chemical for use in cosmetics, food additives, and personal care products. Acute overexposure to the chemical results in symptoms comparable to overexposure to other generally benign chemicals (i.e. ethanol or sodium chloride) and include irritation of the eyes, skin, and mucus membranes. Other effects of exposure to n-butanol mirror those of short-chain alcohols (i.e. ethanol and isopropanol) and include central nervous system depression. These concerns aside, n-butanol has not been shown to cause cancer or any DNA damage. In most cases, n-butanol is rapidly metabolized to carbon dioxide and readily excreted via respiration. n-butanol is also essentially non-toxic to aquatic life and birds with regards to acute exposure. Furthermore, n-butanol is readily biodegradable, which combined with our renewable process, makes the use of Green Biologics nC4-OL environmentally benign from start to finish.

Environmental Impacts

Several natural sources emit a significant amount of n-butanol into the environment. Plants (rye and grass), trees (beech, birch, and hornbeam), animal waste, microbes, and insects all naturally emit n-butanol into the environment. While less volatile than other chemicals, n-butanol is a volatile organic compound (VOC) with a boiling point of 243.3 °F (117.4 °C). However, n-butanol is readily degraded in water and in air (by photo-degradation). Despite its classification as a VOC, n-butanol is more likely to be dissolved in water than evaporate, where it is largely non-toxic to aquatic species and is rapidly degraded. Adsorption of n-butanol into soil is possible, however bioaccumulation and/or bio-concentration are unlikely considering the rapid degradation of the compound.