Methyl ethyl ketone is used as a solvent for lacquers, adhesives, cleaning materials to be electroplated, degreasing, rubber and rubber cement, printing inks, and paints, wood stains and varnishes, paint removers, in cleaning solutions, as a catalyst, and as a carrier.
Substance name: Methyl ethyl ketone
CASR number: 78-93-3
Molecular formula: C4H8O
Synonyms: 2-Butanone; MEK; Ethyl methyl ketone; Butanone; methyl acetone; butan-2-one
Methyl ethyl ketone is a colourless liquid with a faint sweet odour.
Melting Point: -86.3°C
Boiling Point: 79.6°C
Vapour Density: 2.5
Specific Gravity: 0.805
Methyl ethyl ketone is a flammable liquid. It is partially soluble in water, and soluble in most other organic solvents. It will float on water while it rapidly dissolves in it.
The National Pollutant Inventory (NPI) holds data for all sources of methyl ethyl ketone emissions in Australia.
Breathing methyl ethyl ketone for short periods of time (i.e. painting in a poorly ventilated area) can affect the nervous system. The effects may be headaches, dizziness, fatigue, narcosis (acts like a narcotic), nausea, vomiting, and cause you to pass out. Methyl ethyl ketone vapour irritates the eyes, nose, and throat. Prolonged contact with the skin will cause irritation. Contact with the eyes can permanently damage them. Repeated exposure may damage the nervous system and may affect the brain.
Entering the body
Methyl ethyl ketone will enter the body if we breathe in contaminated air, or consume food or water that has been contaminated. It can also pass through the skin.
Workers in the industries that use or produce methyl ethyl ketone are at risk of exposure. Consumers can be exposed to methyl ethyl ketone by exposure to air from production and processing facilities using methyl ethyl ketone, or drinking water from contaminated bores. Consumers may also be exposed to methyl ethyl ketone when using consumer products containing methyl ethyl ketone, especially if there is not good ventilation, or by skin contact. Smoking tobacco products and sniffing glues are also ways to be exposed to methyl ethyl ketone.
Workplace exposure standards
Safe Work Australia sets the workplace exposure standard for methyl ethyl ketone through the workplace exposure standards for airborne contaminants:
- Maximum eight hour time weighted average (TWA): 150 parts per million (445 mg/m3)
- Maximum short term exposure limit (STEL): 300 parts per million (890 mg/m3)
These standards are only appropriate for use in workplaces and are not limited to any specific industry or operation. Make sure you understand how to interpret the standards before you use them.
Drinking water guidelines
There is no guideline for methyl ethyl ketone in the Australian Drinking Water Guidelines.
Methyl ethyl ketone will exist as a gas if released to the atmosphere. It dissolves when mixed with water. In the air it quickly is reacted into other chemicals, in the water and soil bacteria break it down. It has slight acute (short-term) toxicity on aquatic life. It has slight chronic (long-term) toxicity to aquatic life. Chronic and acute effects on plants, birds or land animals have not been determined. Methyl ethyl ketone is not expected to bioaccumulate.
Entering the environment
Industrial emissions of methyl ethyl ketone can produce elevated, but still low level concentrations in the atmosphere around the source. Because of its short life expectancy in the atmosphere methyl ethyl ketone is expected to be confined to the local area within which it is emitted. Since it does not bind to soil well, methyl ethyl ketone that makes its way into the ground may move through the ground and enter groundwater (bore water). Because methyl ethyl ketone is used in many consumer products, including tobacco smoke, short-term indoor concentrations may be elevated above the levels considered safe for workers.
Where it ends up
Methyl ethyl ketone enters the air during production, use and transporting it. In the air sunlight will break it down into other chemicals in a day or less. It dissolves when mixed with water. In water it will be broken down into other chemicals in about two weeks. In the soil and water, bacteria will break it down. It does not deposit on the bottom of rivers or lakes.
No national guidelines.
The primary sources of Methyl ethyl ketone emissions are the industries that manufacture it or use it in production, such as the chemical industry, rubber manufacturers, pharmaceutical industry, the semiconductor industry, heavy equipment manufacturing, manufacturers of millwork, veneer and plywood and the manufacturers of paints, inks, varnishes and lacquers. These are emissions to the air unless there is a spill.
Diffuse sources, and industry sources included in diffuse emissions data
Other possible emitters of Methyl ethyl ketone are commercial and household painting and paint, varnish and lacquer removal, tobacco smoke, and consumer products containing Methyl ethyl ketone. These are emissions to the air unless there is a spill.
Methyl ethyl ketone occurs naturally in volcanoes, forest and bush fires, products of biological degradation, and in some foods.
Methyl ethyl ketone is found in motor vehicle exhaust.
Aerosol paints, architectural coatings, automobile and machinery paints and primers, household hard surface cleaners, household dyes and tints, inks, insecticides for yard and garden, laundry starches, lubricating greases and oils, automotive chemicals, markers, nail polish and polish remover, paints, varnish and paint and varnish removers and thinners, shoe polish, interior clear finishes, undercoats, and primers, waterproofing compounds, particleboard, and wood office furniture.
Sources used in preparing this information
- Agency for Toxic Substances and Disease Registry (1997), ToxFAQS Methyl ethyl ketone (accessed, May, 1999)
- Australian and New Zealand Environment and Conservation Council (ANZECC) (1992) Australian Water Quality Guidelines for Fresh and Marine Waters
- CalEPA Air Resources Board Toxic Air Contaminant Summary Methyl ethyl ketone (accessed, May, 1999)
- ChemFinder WebServer Project (1995), Methyl ethyl ketone (accessed, May, 1999)
- Cornell University, Planning Design and Construction, MSDS, Methyl ethyl ketone (accessed, May, 1999)
- Environmental Defense Fund (1998), Methyl ethyl ketone: The Chemical Scorecard: (accessed, May, 1999)
- Environmental Health Center, a division of the National Safety Council, Environment Writer – Chemical Backgrounders Methyl ethyl ketone (C4H8O) (July, 1997) (accessed, May, 1999)
- National Environment Protection Council (1998a), National Environment Protection Measure for the National Pollutant Inventory (accessed, May, 1999)
- New Jersey Department of Health and Senior Services (1995), Hazardous Substance Fact Sheet, Methyl ethyl ketone, PO Box 368, Trenton, NJ.
- New Jersey Department of Health, Right to Know Program (1986), TRIFacts, Methyl ethyl ketone (accessed, May, 1999)
- NTP Chemical Repository, Radian Corporation, Methyl ethyl ketone (AUGUST 29, 1991) (accessed, May, 1999)
- Technical Advisory Panel (1999), Final Report to the National Environment Protection Council.
- US Environmental Protection Agency and the Office of Pollution Prevention and toxics, (September, 1994), chemicals in the environment: Methyl ethyl ketone (accessed, May, 1999)
- Worksafe Australia (1996), Hazardous Substance Methyl ethyl ketone (accessed, May, 1999)
- Safe Work Australia, Workplace exposure standards for airborne contaminants, accessed December 2018.
- National Health and Medical Research Council (NHMRC), Australian Drinking Water Guidelines (2011) - Updated October 2017, accessed May 2018