Methyl ethyl ketone

The background information page contains information and concepts that will be useful in understanding some of the issues surrounding the NPI. It is strongly recommended that you read this before reading the information presented below.

For an explanation of some of the terms used in this page, see the Glossary

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;

Physical and chemical properties *Physical properties:* Methyl ethyl ketone is a colourless liquid with a faint sweet odour. Melting Point (°C) -86.3 Boiling Point (°C) 79.6; Vapour Density 2.5 Specific Gravity 0.805 *Chemical properties:* 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. Flashpoint: (°C) -6
Common uses 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.
Sources of emissions Point sources 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 point sources included in aggregated 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. Natural sources Methyl ethyl ketone occurs naturally in volcanoes, forest and bush fires, products of biological degradation, and in some foods. Mobile sources Methyl ethyl ketone is found in motor vehicle exhaust. Consumer products which may contain Methyl ethyl ketone 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.
Health effects How might I be exposed to Methyl ethyl ketone? 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. By what pathways might Methyl ethyl ketone enter my 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. Relative health hazard On a health hazard spectrum of 0 - 3 Methyl ethyl ketone registers 1.2. A score of 3 represents a very high hazard to health, 2 represents a medium hazard and 1 is harmful to health. Factors that are taken into account to obtain this ranking include the extent of the material's toxic or poisonous nature and/or its lack of toxicity, and the evaluation of its tendency to cause, or not cause cancer and/or birth defects. It does not take into account exposure to the substance. Human exposure is reflected in the NPI rank given to this substance (see comparative data below). A substance that scores highly as a health hazard is arsenic at 2.3 and one of the lowest scores is ammonia at 1.0. Health guidelines Worksafe Australia: For methyl ethyl ketone, it is allowable for workers to be exposed to concentrations of 150 parts per million over an eight hour workshift, with concentrations not greater than 300 parts per million. See the Additional Information page for current health information. The Australian NOHSC National Exposure Standards Database link is probably the most useful source of information. Note that the emissions data in the NPI database is not directly comparable with these guidelines. What effect might Methyl ethyl ketone have on my health? 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.
Environmental effects *Environmental Fate* 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. Environmental Transport 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. Relative hazard to the environment On an environmental spectrum of 0 - 3 Methyl ethyl ketone registers 1. A score of 3 represents a very high hazard to the environment and 0 a negligible hazard. Factors that are taken into account to obtain this ranking include the extent of the material's toxic or poisonous nature and/or its lack of toxicity, and the measure of its ability to remain active in the environment and whether it accumulates in living organisms. It does not take into exposure to the substance. Environmental exposure is reflected in the NPI rank for this substance (see comparative data below). A substance that scores highly as an environmental hazard is oxides of nitrogen at 3.0 and one of the lower scores is carbon monoxide at 0.8. Environmental guidelines See the Additional Information page for current environmental guidelines. No national guidelines. What effect might Methyl ethyl ketone have on the environment? 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.
Comparative data NPI Rank Approximately 400 substances were considered for inclusion on the NPI reporting list. A risk ranking was given based on health and environmental hazard identification and human and environmental exposure to the substance. Some substances were grouped together at the same rank with 208 ranks in total. Methyl ethyl ketone was ranked as 21 out of the 208 ranks. Total hazard score (human health + environmental criteria) = 2.2.
Sources of information used in preparing this article 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), Exposure Standard Methyl ethyl ketone (accessed, May, 1999) Worksafe Australia (1996), Hazardous Substance Methyl ethyl ketone (accessed, May, 1999)

National Substance Emission Report