What is methyl ethyl ketone?

Methyl ethyl ketone, also known as butanone, is a colorless, highly volatile ketone with a characteristic sweet, pungent odor. It is mainly used as a solvent in the paint, adhesive, printing ink, and plastics industries. MEK has good solvency properties for many plastics, resins, and oils and, due to its fast evaporation rate, is particularly used in processes with short drying times.

Formation

MEK is mainly produced industrially by the dehydrogenation of 2-butanol, which produces water as a by-product. Other production processes include the catalytic oxidation of n-butane or butenes. MEK also occurs naturally in small quantities in foods such as butter and some fruits.

Detection

MEK is a clear, colorless liquid with a distinctive, sweetish-pungent odor that is noticeable even in low concentrations. It is highly flammable, miscible with water, and dissolves many organic materials. Due to its high volatility, MEK evaporates quickly at room temperature, which can lead to rapid accumulation in the air if ventilation is inadequate.

Limit values

The occupational exposure limit (OEL) for MEK in the EU is 200 ppm (600 mg/m³) as a time-weighted average over eight hours. Short-term values must not exceed 300 ppm (900 mg/m³). Due to its volatile and irritating properties, good technical ventilation is required when working with MEK.

Hazards

MEK is irritating to the eyes and respiratory tract. Prolonged or repeated exposure may cause headaches, dizziness, drowsiness, and, in high concentrations, central nervous system disorders. Skin contact may cause dryness and cracking. MEK is highly flammable and forms explosive mixtures with air. It is biodegradable in the environment but may harm aquatic organisms at high concentrations.