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Methyl Ethyl Ketone

What are other names or identifying information for methyl ethyl ketone?

CAS Registry No.: 78-93-3
Other Names: MEK, 2-Butanone, Methyl acetone
Main Uses: Solvent, chemical intermediate
Appearance: Clear colourless volatile liquid.
Odour: Sweet

Canadian TDG: UN1193

What is the WHMIS 1988 classification?

B2 - Flammable Liquid; D2B - Toxic (Eye irritant)

Symbol for Class B
Class B2
Symbol for Class D2
Class D2B

What are the most important things to know about methyl ethyl ketone in an emergency?

Emergency Overview: Clear colourless volatile liquid. Sweet odour. HIGHLY FLAMMABLE LIQUID AND VAPOUR. Distant ignition and flashback are possible. May cause drowsiness and dizziness. IRRITANT. Causes moderate or severe eye irritation. ASPIRATION hazard. May be harmful if swallowed and enters airways.

What are the potential health effects of methyl ethyl ketone?

Main Routes of Exposure: Inhalation. Skin contact. Eye contact.

  • Inhalation: Can irritate the nose and throat. At high concentrations: can harm the nervous system. Symptoms may include headache, nausea, dizziness, drowsiness and confusion. A severe exposure can cause unconsciousness.
  • Skin Contact: May cause mild irritation. Can be absorbed through the skin, but harmful effects are not expected.
  • Eye Contact: EYE IRRITANT. Causes moderate to severe irritation. Symptoms include sore, red eyes, and tearing. The vapour also irritates the eyes.
  • Ingestion: If large amounts are ingested: Can cause effects as described for inhalation. May be drawn into the lungs if swallowed or vomited, causing severe lung damage. Death can result.
  • Effects of Long-Term (Chronic) Exposure:  Can cause dry, red, cracked skin (dermatitis) following skin contact. May harm the nervous system. Conclusions cannot be drawn from the limited studies available.
  • Carcinogenicity: Not known to cause cancer.

International Agency for Research on Cancer (IARC): Not specifically evaluated.
American Conference for Governmental Industrial Hygienists (ACGIH): Not specifically designated.

  • Teratogenicity / Embryotoxicity:  Not known to harm the unborn child.
  • Reproductive Toxicity: Not known to be a reproductive hazard.
  • Mutagenicity: Not known to be a mutagen.

What are first aid measures for methyl ethyl ketone?

Inhalation: Take precautions to prevent a fire (e.g. remove sources of ignition). Move victim to fresh air. Call a Poison Centre or doctor if the victim feels unwell.

Skin Contact: Take off contaminated clothing, shoes and leather goods (e.g. watchbands, belts). Flush with lukewarm, gently flowing water for 5 minutes. If irritation or pain persists, see a doctor. Thoroughly clean clothing, shoes and leather goods before reuse or dispose of safely.

Eye Contact: Immediately flush the contaminated eye(s) with lukewarm, gently flowing water for 15-20 minutes, while holding the eyelid(s) open. If a contact lens is present, DO NOT delay flushing or attempt to remove the lens. Take care not to rinse contaminated water into the unaffected eye or onto the face. If irritation or pain persists, see a doctor.

Ingestion: Have victim rinse mouth with water. If vomiting occurs naturally, have victim lean forward to reduce risk of aspiration. Have victim rinse mouth with water again. Immediately call a Poison Centre or doctor.

First Aid Comments: All first aid procedures should be periodically reviewed by a doctor familiar with the chemical and its conditions of use in the workplace.

What are fire hazards and extinguishing media for methyl ethyl ketone?

Flammable Properties: HIGHLY FLAMMABLE LIQUID. Can ignite at room temperature. Releases vapour that can form explosive mixture with air. Can be ignited by static discharge.

Suitable Extinguishing Media: Carbon dioxide, dry chemical powder, appropriate foam, water spray or fog. Foam manufacturers should be consulted for recommendations regarding types of foams and application rates. Use water to keep non-leaking, fire-exposed containers cool.

Specific Hazards Arising from the Chemical: Vapour may travel a considerable distance to a source of ignition and flash back to a leak or open container. Vapour may accumulate in hazardous amounts in low-lying areas especially inside confined spaces, resulting in a toxicity hazard. Closed containers may rupture violently when heated releasing contents. In a fire, the following hazardous materials may be generated: very toxic carbon monoxide, carbon dioxide; toxic, flammable aldehydes; and other chemicals.

What are the stability and reactivity hazards of methyl ethyl ketone?

  • Chemical Stability:  Normally stable.
  • Conditions to Avoid: Open flames, sparks, static discharge, heat and other ignition sources. Prolonged exposure air and heat. Prolonged storage.
  • Incompatible Materials: Reacts violently with: strong oxidizing agents (e.g. perchloric acid), strong acids (e.g. hydrochloric acid). Not corrosive to: aluminum alloys, carbon steel.
  • Hazardous Decomposition Products: Very toxic carbon monoxide, carbon dioxide; very toxic, flammable formaldehyde; corrosive acetic acid; and other chemicals.
  • Possibility of Hazardous Reactions: Prolonged (12 month) exposure to air and heat, or long-term storage can produce explosive peroxides.

What are accidental release measures for methyl ethyl ketone?

Personal Precautions:  Evacuate the area immediately. Isolate the hazard area. Keep out unnecessary and unprotected personnel. Eliminate all ignition sources. Use grounded, explosion-proof equipment.

Methods for Containment and Clean-up: Contain and soak up spill with absorbent that does not react with spilled product.  Contaminated absorbent poses the same hazard as the spilled product. Large spills or leaks: contact emergency services and manufacturer/supplier for advice.

Other Information: Report spills to local health, safety and environmental authorities, as required.

What handling and storage practices should be used when working with methyl ethyl ketone?

Handling:  Eliminate heat and ignition sources such as sparks, open flames, hot surfaces and static discharge. Post "No Smoking" signs. Electrically bond and ground equipment. Ground clips must contact bare metal. Avoid generating vapours or mists.

Storage: Store in an area that is: cool, well-ventilated, clear of combustible and flammable materials (e.g. old rags, cardboard), separate from incompatible materials, out of direct sunlight and away from heat and ignition sources. Electrically bond and ground containers. Ground clips must contact bare metal.

What is the American Conference of Governmental Industrial Hygienists (ACGIH®) recommended exposure limit for methyl ethyl ketone?

ACGIH® TLV® - TWA:  200 ppm BEI

ACGIH® TLV® - STEL [C]:  300 ppm

Exposure Guideline Comments: TLV® = Threshold Limit Value. TWA = Time-Weighted Average. BEI® = Biological Exposure Index. STEL = Short-term Exposure Limit. C = Ceiling limit

What are the engineering controls for methyl ethyl ketone?

Engineering Controls:  Use a local exhaust ventilation and enclosure, if necessary, to control amount in the air. For large scale use of this product: use non-sparking ventilation systems, approved explosion-proof equipment and intrinsically safe electrical systems in areas where this product is used and stored.

What Personal Protective Equipment (PPE) is needed when working with methyl ethyl ketone?

Eye/Face Protection: Wear chemical safety goggles and face shield when contact is possible.

Skin Protection: Avoid repeated or prolonged skin contact. Wear chemical protective clothing e.g. gloves, aprons, boots. Suitable materials include: Barrier® (PE/PA/PE), Silver Shield/4H® (PE/EVAL/PE), Trellchem® HPS, Trellchem® VPS, Tychem® BR/LV, Tychem® Responder, Tychem® TK.

Respiratory Protection: Up to 3000 ppm: wear a NIOSH approved, full facepiece air-purifying respirator with organic vapour cartridges. Wear a NIOSH approved, full facepiece self-contained breathing apparatus (SCBA) or supplied air respirator.

Document last updated on January 28, 2013


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