Methyl Ethyl Ketone (MEK) is a small, four-carbon organic compound widely produced and used in industry. This chemical belongs to the ketone family of molecules, characterized by a carbonyl group within the carbon chain. MEK is commercially significant and is commonly known as butanone, or 2-butanone.
Fundamental Characteristics
Methyl Ethyl Ketone is a clear, colorless liquid at room temperature. It is highly volatile, meaning it evaporates quickly, which contributes to its effectiveness as a solvent. MEK possesses a distinct, sharp, sweet odor often compared to acetone or butterscotch.
The compound is flammable, and its vapors are denser than air, allowing them to travel along the ground to an ignition source. MEK exhibits partial solubility in water, distinguishing it from many other organic solvents. Its chemical structure makes it an effective polar solvent capable of dissolving a variety of substances.
Primary Industrial and Consumer Applications
MEK is a highly effective solvent due to its ability to dissolve other materials. It is a preferred choice in industrial settings because it has a slower evaporation rate and a slightly higher boiling point than acetone, allowing it to work longer on a surface.
MEK is a primary component in lacquer thinners, varnishes, and paint removers, where it helps maintain a smooth application and proper adhesion. It is extensively used in the manufacturing of various plastics, synthetic rubber, and textiles.
The solvent power of MEK is also used to process materials like vinyl resins, cellulose acetate, and nitrocellulose coatings. Consumers may encounter MEK in products such as certain glues and dry-erase markers. Furthermore, it is a strong industrial cleaning agent used for degreasing machinery and removing adhesives and residues.
Handling and Exposure Safety
Exposure to MEK can occur through inhalation of its vapors, direct skin or eye contact, and accidental ingestion. Inhalation is the most common route of exposure, particularly in poorly ventilated areas.
Acute exposure to MEK vapors can cause irritation to the eyes, nose, and throat. Higher concentrations may lead to central nervous system effects, including headaches, dizziness, nausea, and drowsiness. If the liquid contacts the skin, it can cause irritation, redness, and a burning sensation, and repeated exposure can result in dryness and cracking.
Ingestion is particularly hazardous because the liquid can enter the lungs if swallowed or vomited, a condition known as aspiration, which can cause severe damage. Regulatory bodies, such as the Occupational Safety and Health Administration (OSHA), have established Permissible Exposure Limits (PELs) to protect workers. The OSHA PEL for MEK is 200 parts per million (ppm) averaged over an eight-hour workday, with a Short-Term Exposure Limit (STEL) of 300 ppm over a 15-minute period.
To minimize exposure, proper ventilation, such as local exhaust systems, is necessary to keep airborne concentrations below these limits. Workers must wear appropriate Personal Protective Equipment (PPE) to prevent direct contact. This includes solvent-resistant gloves, chemical safety goggles, and protective clothing.
Due to its flammability, MEK must be stored and handled far from ignition sources. Containers should be kept tightly closed in a cool, well-ventilated area to prevent vapor buildup. Following established safety protocols mitigates both the fire and health risks associated with working with MEK.