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Chemical Datasheet

METHYL ETHYL KETONE

3 - Flammable liquid

Chemical Identifiers

CAS Number UN/NA Number DOT Hazard Label USCG CHRIS Code
  • 78-93-3   (METHYL ETHYL KETONE)
  • 1193
  • Flammable Liquid
  • MEK
NIOSH Pocket Guide International Chem Safety Card
2-Butanone
  • METHYL ETHYL KETONE
NFPA 704
Diamond Hazard Value Description
3
1 0
Blue Health 1 Can cause significant irritation.
Red Flammability 3 Can be ignited under almost all ambient temperature conditions.
Yellow Instability 0 Normally stable, even under fire conditions.
White Special
(NFPA, 2010)
General Description
Colorless fairly volatile liquid with a pleasant pungent odor. Flash point 20°F. Vapors heavier than air. Does not react with water or many common materials. Stable in normal transportation. Irritates the nose, eyes, and throat. Combustion may produce toxic materials. Density 6.7 lb / gal. Used as a solvent, for making other chemicals, and for production of wax from petroleum.

Hazards

Reactivity Alerts
Air & Water Reactions
Highly flammable. Soluble in water.
Fire Hazard
Excerpt from 127 Polymerizable warning [Flammable Liquids (Water-Miscible)]:

HIGHLY FLAMMABLE: Will be easily ignited by heat, sparks or flames. CAUTION: Ethanol (UN1170) can burn with an invisible flame. Use an alternate method of detection (thermal camera, broom handle, etc.) Vapors may form explosive mixtures with air. Vapors may travel to source of ignition and flash back. Most vapors are heavier than air. They will spread along the ground and collect in low or confined areas (sewers, basements, tanks, etc.). Vapor explosion hazard indoors, outdoors or in sewers. Those substances designated with a (P) may polymerize explosively when heated or involved in a fire. Runoff to sewer may create fire or explosion hazard. Containers may explode when heated. Many liquids will float on water. (ERG, 2020)
Health Hazard
Liquid causes eye burn. Vapor irritates eyes, nose, and throat; can cause headache, dizziness, nausea, weakness, and loss of consciousness. (USCG, 1999)
Reactivity Profile
METHYL ETHYL KETONE is explosive in the form of vapor when exposed to heat, flame or sparks. Ignition on contact with potassium tert-butoxide. Reactive with strong oxidizing materials, and will dissolve or soften some plastics. Mixture with 2-propanol will form explosive peroxides during storage. Vigorous reaction with chloroform in the presence of alkali (sodium hydroxide, potassium hydroxide), chlorosulfonic acid, fuming sulfuric acid (oleum) [Lewis, 3rd ed., 1993, p. 855]. Reaction with hydrogen peroxide in the presence of nitric acid forms heat- and shock-sensitive explosive acetone peroxides. [Bjorklund, G. H. et al., Trans. R. Soc. Can, 1950, 44, p. 25].
Belongs to the Following Reactive Group(s)
Potentially Incompatible Absorbents

No information available.

Response Recommendations

Isolation and Evacuation
Excerpt from 127 Polymerizable warning [Flammable Liquids (Water-Miscible)]:

IMMEDIATE PRECAUTIONARY MEASURE: Isolate spill or leak area for at least 50 meters (150 feet) in all directions.

LARGE SPILL: Consider initial downwind evacuation for at least 300 meters (1000 feet).

FIRE: If tank, rail car or tank truck is involved in a fire, ISOLATE for 800 meters (1/2 mile) in all directions; also, consider initial evacuation for 800 meters (1/2 mile) in all directions. (ERG, 2020)
Firefighting
Excerpt from 127 Polymerizable warning [Flammable Liquids (Water-Miscible)]:

CAUTION: The majority of these products have a very low flash point. Use of water spray when fighting fire may be inefficient. CAUTION: For fire involving UN1170, UN1987 or UN3475, alcohol-resistant foam should be used. CAUTION: Ethanol (UN1170) can burn with an invisible flame. Use an alternate method of detection (thermal camera, broom handle, etc.).

SMALL FIRE: Dry chemical, CO2, water spray or alcohol-resistant foam.

LARGE FIRE: Water spray, fog or alcohol-resistant foam. Avoid aiming straight or solid streams directly onto the product. If it can be done safely, move undamaged containers away from the area around the fire.

FIRE INVOLVING TANKS OR CAR/TRAILER LOADS: Fight fire from maximum distance or use unmanned master stream devices or monitor nozzles. Cool containers with flooding quantities of water until well after fire is out. Withdraw immediately in case of rising sound from venting safety devices or discoloration of tank. ALWAYS stay away from tanks engulfed in fire. For massive fire, use unmanned master stream devices or monitor nozzles; if this is impossible, withdraw from area and let fire burn. (ERG, 2020)
Non-Fire Response
Excerpt from 127 Polymerizable warning [Flammable Liquids (Water-Miscible)]:

ELIMINATE all ignition sources (no smoking, flares, sparks or flames) from immediate area. All equipment used when handling the product must be grounded. Do not touch or walk through spilled material. Stop leak if you can do it without risk. Prevent entry into waterways, sewers, basements or confined areas. A vapor-suppressing foam may be used to reduce vapors. Absorb or cover with dry earth, sand or other non-combustible material and transfer to containers. Use clean, non-sparking tools to collect absorbed material.

LARGE SPILL: Dike far ahead of liquid spill for later disposal. Water spray may reduce vapor, but may not prevent ignition in closed spaces. (ERG, 2020)
Protective Clothing
Excerpt from NIOSH Pocket Guide for 2-Butanone:

Skin: PREVENT SKIN CONTACT - Wear appropriate personal protective clothing to prevent skin contact.

Eyes: PREVENT EYE CONTACT - Wear appropriate eye protection to prevent eye contact.

Wash skin: WHEN CONTAMINATED - The worker should immediately wash the skin when it becomes contaminated.

Remove: WHEN WET (FLAMMABLE) - Work clothing that becomes wet should be immediately removed due to its flammability hazard (i.e., for liquids with a flash point <100°F).

Change: No recommendation is made specifying the need for the worker to change clothing after the workshift.

Provide: EYEWASH - Eyewash fountains should be provided in areas where there is any possibility that workers could be exposed to the substances; this is irrespective of the recommendation involving the wearing of eye protection. (NIOSH, 2023)
DuPont Tychem® Suit Fabrics
Normalized Breakthrough Times (in Minutes)
Chemical CAS Number State QS QC SL C3 TF TP RC TK RF
Butanone 78-93-3 Liquid 18 >480 40*/64 40*/64 >480 >480 >480
MEK 78-93-3 Liquid 18 >480 40*/64 40*/64 >480 >480 >480
Methyl ethyl ketone 78-93-3 Liquid 18 >480 40*/64 40*/64 >480 >480 >480
> indicates greater than.
* indicates based on lowest single value.

Special Warning from DuPont: Tychem® and Tyvek® fabrics should not be used around heat, flames, sparks or in potentially flammable or explosive environments. Only...

(DuPont, 2023)

First Aid
EYES: First check the victim for contact lenses and remove if present. Flush victim's eyes with water or normal saline solution for 20 to 30 minutes while simultaneously calling a hospital or poison control center. Do not put any ointments, oils, or medication in the victim's eyes without specific instructions from a physician. IMMEDIATELY transport the victim after flushing eyes to a hospital even if no symptoms (such as redness or irritation) develop.

SKIN: IMMEDIATELY flood affected skin with water while removing and isolating all contaminated clothing. Gently wash all affected skin areas thoroughly with soap and water. If symptoms such as redness or irritation develop, IMMEDIATELY call a physician and be prepared to transport the victim to a hospital for treatment.

INHALATION: IMMEDIATELY leave the contaminated area; take deep breaths of fresh air. If symptoms (such as wheezing, coughing, shortness of breath, or burning in the mouth, throat, or chest) develop, call a physician and be prepared to transport the victim to a hospital. Provide proper respiratory protection to rescuers entering an unknown atmosphere. Whenever possible, Self-Contained Breathing Apparatus (SCBA) should be used; if not available, use a level of protection greater than or equal to that advised under Protective Clothing.

INGESTION: DO NOT INDUCE VOMITING. Volatile chemicals have a high risk of being aspirated into the victim's lungs during vomiting which increases the medical problems. If the victim is conscious and not convulsing, give 1 or 2 glasses of water to dilute the chemical and IMMEDIATELY call a hospital or poison control center. IMMEDIATELY transport the victim to a hospital. If the victim is convulsing or unconscious, do not give anything by mouth, ensure that the victim's airway is open and lay the victim on his/her side with the head lower than the body. DO NOT INDUCE VOMITING. IMMEDIATELY transport the victim to a hospital. (NTP, 1992)

Physical Properties

Chemical Formula:
  • C4H8O
Flash Point: 26°F (NTP, 1992)
Lower Explosive Limit (LEL): 1.8 % (NTP, 1992)
Upper Explosive Limit (UEL): 10 % (NTP, 1992)
Autoignition Temperature: 961°F (USCG, 1999)
Melting Point: -123.3°F (NTP, 1992)
Vapor Pressure: 77.5 mmHg at 68°F ; 100 mmHg at 77.0°F (NTP, 1992)
Vapor Density (Relative to Air): 2.42 (NTP, 1992) - Heavier than air; will sink
Specific Gravity: 0.806 at 68°F (USCG, 1999) - Less dense than water; will float
Boiling Point: 175.3°F at 760 mmHg (NTP, 1992)
Molecular Weight: 72.11 (NTP, 1992)
Water Solubility: greater than or equal to 100 mg/mL at 66°F (NTP, 1992)
Ionization Energy/Potential: 9.54 eV (NIOSH, 2023)
IDLH: 3000 ppm (NIOSH, 2023)

AEGLs (Acute Exposure Guideline Levels)

Final AEGLs for Methyl ethyl ketone (78-93-3)
Exposure Period AEGL-1 AEGL-2 AEGL-3
10 minutes 200 ppm 4900 ppm 1-flame icon indicates value is 10-49% of LEL. Safety consideration against explosions must be taken into account. 10000 ppm 2-flame icon indicates value is 50-99% of LEL. Extreme safety consideration against explosions must be taken into account.
30 minutes 200 ppm 3400 ppm 1-flame icon indicates value is 10-49% of LEL. Safety consideration against explosions must be taken into account. 10000 ppm 2-flame icon indicates value is 50-99% of LEL. Extreme safety consideration against explosions must be taken into account.
60 minutes 200 ppm 2700 ppm 1-flame icon indicates value is 10-49% of LEL. Safety consideration against explosions must be taken into account. 4000 ppm 1-flame icon indicates value is 10-49% of LEL. Safety consideration against explosions must be taken into account.
4 hours 200 ppm 1700 ppm 2500 ppm 1-flame icon indicates value is 10-49% of LEL. Safety consideration against explosions must be taken into account.
8 hours 200 ppm 1700 ppm 2500 ppm 1-flame icon indicates value is 10-49% of LEL. Safety consideration against explosions must be taken into account.
Lower Explosive Limit (LEL) = 18000 ppm
1-flame icon indicates value is 10-49% of LEL. Safety consideration against explosions must be taken into account.
2-flame icon indicates value is 50-99% of LEL. Extreme safety consideration against explosions must be taken into account.
(NAC/NRC, 2023)

ERPGs (Emergency Response Planning Guidelines)

No ERPG information available.

PACs (Protective Action Criteria)

Chemical PAC-1 PAC-2 PAC-3
Butanone, 2-; (Methyl ethyl ketone; MEK) (78-93-3) 200 ppm 2700 ppm 1-flame icon indicates value is 10-49% of LEL. 4000 ppm 1-flame icon indicates value is 10-49% of LEL. LEL = 18000 ppm
1-flame icon indicates value is 10-49% of LEL.
(DOE, 2018)

Regulatory Information

EPA Consolidated List of Lists

Regulatory Name CAS Number/
313 Category Code
EPCRA 302
EHS TPQ
EPCRA 304
EHS RQ
CERCLA RQ EPCRA 313
TRI
RCRA
Code
CAA 112(r)
RMP TQ
Methyl ethyl ketone 78-93-3 5000 pounds U159

(EPA List of Lists, 2022)

CISA Chemical Facility Anti-Terrorism Standards (CFATS)

No regulatory information available.

OSHA Process Safety Management (PSM) Standard List

No regulatory information available.

Alternate Chemical Names