Methyl Ethyl Ketone

Methyl ethyl ketone(MEK), also known as butanone, is anorganic compoundwith the molecular formulaCH3C(O)CH2CH3. This colourless liquidketonehas a sharp, sweet odour reminiscent ofbutterscotchandacetone. It is produced industrially on a large scale, and also occurs in trace amounts in nature. It is soluble in water and is commonly used as an industrial solvent. [fusion_builder_container hundred_percent=”yes” overflow=”visible”][fusion_builder_row][fusion_builder_column type=”1_1″ background_position=”left top” background_color=”” border_size=”” border_color=”” border_style=”solid” spacing=”yes” background_image=”” background_repeat=”no-repeat” padding=”” margin_top=”0px” margin_bottom=”0px” class=”” id=”” animation_type=”” animation_speed=”0.3″ animation_direction=”left” hide_on_mobile=”no” center_content=”no” min_height=”none”][1]

 

Uses [2]

 

MEK is a liquid solvent used in surface coatings, adhesives, printing inks, chemical intermediates, magnetic tapes and lube oil de-waxing agents. It is also used as an extraction medium for fats, oils, waxes and resins. It is a highly efficient and versatile solvent for surface coatings. Because of its effectiveness as a solvent, MEK is especially valuable in formulating high solids coatings, which help to reduce emissions from coating operations. MEK is a natural component of many foods, including apple juice, beans, chicken, honey and a variety of cheeses.

 

Sources of Emission & Routes of Exposure

 

Sources of Emission [3]

 

  • Industry sources: The primary sources of MEK 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: Other possible emitters of MEK 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: MEK occurs naturally in volcanoes, forest and bush fires, products of biological degradation, and in some foods.
  • Transport sources: MEK is found in motor vehicle exhaust.
  • Consumer products: 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.

 

Routes of Exposure [4]

 

  • Breathing contaminated air from the production or use of paints, glues, coatings, or cleaning agents containing it.
  • Breathing contaminated air near hazardous waste sites.
  • Breathing cigarette smoke.
  • Sniffing glues.
  • Drinking contaminated water from wells near manufacturing or hazardous waste sites.
  • Skin contact with the liquid during production or use.

 

Health Effects [5]

 

Acute Effects

 

  • Acute exposure of humans to high concentrations of MEK produces irritation to the eyes, nose, and throat.
  • Other effects reported from acute inhalation exposure in humans include central nervous system depression, headache, and nausea.
  • Dermatitis has been reported in humans following dermal exposure to MEK.
  • Tests involving acute exposure of rabbits have shown MEK to have high acute toxicity from dermal exposure, while acute oral exposure of rats and mice has shown the chemical to have moderate toxicity from ingestion.
  • Acute inhalation tests in rats indicate low toxicity from MEK exposure via inhalation.

 

Chronic Effects

 

  • Limited information is available on the chronic effects of MEK in humans from inhalation exposure. One study reported nerve damage in individuals who sniffed a glue thinner containing MEK and other chemicals.
  • Slight neurological, liver, kidney, and respiratory effects have been reported in chronic inhalation studies of MEK in animals.
  • The Reference Concentration (RfC) for MEK is 1 milligram per cubic metre (mg/m3) based on decreased foetal birth weight in mice.
  • The Reference Dose (RfD) for MEK is 0.6 milligrams per kilogram body weight per day (mg/kg/d) based on decreased foetal birth weight in rats.

 

Reproductive/Developmental Effects:

 

  • No information on the reproductive or developmental effects of MEK in humans was located.
  • An inhalation study in mice exposed to MEK reported decreased foetal weight and foetal malformations. Developmental effects have also been reported in rats following oral and inhalation exposures.

 

Cancer Risk

 

  • No information on the carcinogenicity of MEK in humans was located.
  • No studies were available on the carcinogenicity of MEK by the oral or inhalation routes. In a dermal carcinogenicity study, skin tumours were not reported from MEK.
  • EPA has classified MEK as a Group D, not classifiable as to human carcinogenicity, based on a lack of data concerning carcinogenicity in humans and animals.

 

Safety [6]

 

First Aid Measures

 

  • Eye Contact: Check for and remove any contact lenses. Immediately flush eyes with running water for at least 15 minutes, keeping eyelids open. Cold water may be used. Get medical attention.
  • Skin Contact: In case of contact, immediately flush skin with plenty of water. Cover the irritated skin with an emollient. Remove contaminated clothing and shoes. Cold water may be used. Wash clothing before reuse. Thoroughly clean shoes before reuse. Get medical attention.
  • Serious Skin Contact: Wash with a disinfectant soap and cover the contaminated skin with an anti-bacterial cream. Seek medical attention.
  • Inhalation: If inhaled, remove to fresh air. If not breathing, give artificial respiration. If breathing is difficult, give oxygen. Get medical attention.
  • Serious Inhalation: Evacuate the victim to a safe area as soon as possible. Loosen tight clothing such as a collar, tie, belt or waistband. If breathing is difficult, administer oxygen. If the victim is not breathing, perform mouth-to-mouth resuscitation. Seek medical attention.
  • Ingestion: Do NOT induce vomiting unless directed to do so by medical personnel. Never give anything by mouth to an unconscious person. Loosen tight clothing such as a collar, tie, belt or waistband. Get medical attention if symptoms appear.

 

Fire & Explosion Information

 

  • MEK is flammable
  • Auto-Ignition Temperature is 404°C (759.2°F)
  • MEK is highly flammable in presence of open flames and sparks, of heat.
  • MEK is explosive in presence of oxidising materials.
  • Small fires can be extinguished with dry chemical powder.
  • For large fires, use alcohol foam, water spray or fog.
  • MEK will ignite on contact with potassium t-butoxide.
  • Vapour may cause a flash fire
  • Reaction with Hydrogen Peroxide + nitric acid forms heat and shock-sensitive explosive product. Mixture with 2-propanol will produce explosive peroxides during storage.

 

Exposure Controls & Personal Protection

 

Engineering Controls

 

  • Provide exhaust ventilation or other engineering controls to keep the airborne concentrations of vapours below their respective threshold limit value.
  • Ensure that eyewash stations and safety showers are proximal to the workstation location.

 

Personal Protective Equipment

 

The following personal protective equipment is recommended when handling MEK:

  • Splash goggles;
  • Lab coat;
  • Vapour respirator (be sure to use an approved/certified respirator or equivalent);
  • Gloves.

 

Personal Protective Equipment in Case of a Large Spill:

  • Splash goggles;
  • Full suit;
  • Vapour respirator;
  • Boots;
  • Gloves;
  • A self-contained breathing apparatus should be used to avoid inhalation of the product.
  • Suggested protective clothing might not be sufficient; consult a specialist BEFORE handling this product.

 

Regulation

 

United States [7]

 

Exposure Limit Limit Values HE Codes Health Factors and Target Organs
OSHA Permissible Exposure Limit (PEL) – General Industry

See29 CFR 1910.1000 Table Z-1

200 ppm
(590 mg/m3) TWA
HE16 Irritation of the eyes, nose, and throat
OSHA PEL – Construction Industry

See29 CFR 1926.55 Appendix A

200 ppm
(590 mg/m3) TWA
HE16 Irritation of the eyes, nose, and throat
OSHA PEL – Shipyard Employment

See29 CFR 1915.1000 Table Z-Shipyards

200 ppm
(590 mg/m3) TWA
HE16 Irritation of the eyes, nose, and throat
National Institute for Occupational Safety and Health (NIOSH) Recommended Exposure Limit (REL)(REL listed under ketones) 200 ppm
(590 mg/m3) TWA

300 ppm
(885 mg/m3) STEL

HE8 Narcosis (central nervous system depression)
HE16 Irritation of the eyes, nose, and throat
American Conference of Governmental Industrial Hygienists (ACGIH) Threshold Limit Value (TLV)(2001) (TLV listed under methyl ethyl ketone [MEK]) 200 ppm
(590 mg/m3) TWA

300 ppm
(885 mg/m3) STEL

BEI

HE7 Central nervous system effects and peripheral neuropathy
HE16 Irritation of the eyes, nose, and throat
CAL/OSHA PELs 200 ppm
(590 mg/m3) TWA

300 ppm
(885 mg/m3) STEL

HE7 Central nervous system effects and peripheral neuropathy
HE16 Irritation of the eyes, nose, and throat

 

Australia [3]

 

Safe Work 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.

 

References

 

  1. http://en.wikipedia.org/wiki/Butanone
  2. http://www.americanchemistry.com/ProductsTechnology/Ketones/Methyl-Ethyl-Ketone-MEK.html
  3. http://www.npi.gov.au/resource/methyl-ethyl-ketone
  4. http://www.atsdr.cdc.gov/toxfaqs/tf.asp?id=342&tid=60
  5. http://www.epa.gov/ttn/atw/hlthef/methylet.html
  6. http://www.sciencelab.com/msds.php?msdsId=9927358
  7. https://www.osha.gov/dts/chemicalsampling/data/CH_222300.html

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