What are alcohol compounds?

Alcohol compounds are organic compounds that contain one or more hydroxyl groups (–OH) attached to a saturated carbon atom. They are among the most important and versatile chemical groups and occur both in nature and in a variety of industrial processes. Alcohols are used as solvents, disinfectants, starting materials for chemical syntheses, and as energy sources.

Formation

Alcohol compounds are produced industrially in various ways. Methanol is usually produced by catalytic hydrogenation of carbon monoxide (syngas process), ethanol by fermentation of sugar-containing raw materials or by hydration of ethene. Higher alcohols are often produced by oxo synthesis or by reduction of aldehydes and ketones. Many alcohols are also produced as by-products of other chemical reactions.

Identification

Alcohol compounds usually occur as colorless, clear liquids, many of which have a characteristic, slightly pungent or alcoholic odor. They are often highly soluble in water and form homogeneous mixtures with many organic solvents. Volatility and flammability depend on chain length and structure—short-chain alcohols such as methanol and ethanol are highly volatile and flammable, while long-chain alcohols are less volatile.

Limit values

Permissible occupational exposure limits vary widely. In the EU, the OEL for methanol is 200 ppm (260 mg/m³), for ethanol 1000 ppm (1900 mg/m³) and for isopropanol 200 ppm (500 mg/m³). These values apply to an average exposure time of eight hours and serve to protect against acute and chronic health damage.

Hazards

The hazards of alcohol compounds depend heavily on the specific compound. Methanol is highly toxic and can cause blindness or death even in small amounts. Ethanol is relatively non-toxic in moderate amounts, but can be harmful to health in high concentrations. Isopropanol is irritating and can cause dizziness, lightheadedness, and headaches if inhaled or swallowed. All short-chain alcohols are highly flammable and pose a fire and explosion hazard.