Product Name: Methyl Ethyl Ketone (MEK)
Synonyms: 2-Butanone, MEK, Methyl Acetone
CAS Number: 78-93-3
Recommended Use: Industrial solvent for coatings, adhesives, and chemical intermediates
Supplier Details: Always check drum, tote, or shipping papers for the most accurate address and contact details, as safety alerts and product info often come straight from these.
Emergency Contact: CHEMTREC, local authorities, or site emergency response as listed on shipping label or Safety Data documentation.
GHS Classification: Flammable liquid category 2, Eye irritation category 2A, Specific target organ toxicity (single exposure) category 3, Narcotic effect
Hazard Statements: Can easily catch fire, causes serious eye irritation, may cause drowsiness or dizziness if inhaled
Pictograms: Flame, exclamation mark
Precautionary Statements: Keep away from heat, sparks, open flames; wear eye protection and gloves; avoid breathing vapors; ground and bond container during transfer; wash hands after handling
Signal Word: Danger
Chemical Name: Methyl Ethyl Ketone
Synonym/Common Name: 2-Butanone
Concentration: Typically found at 99%
Impurities/Additives: Small traces of water or other ketones can show up depending on manufacturing process; always good to check the batch certificate if sensitive equipment is involved.
CAS Number: 78-93-3
Inhalation: Remove to fresh air, rest and keep warm, seek medical attention if feeling light-headed or unwell
Skin Contact: Take off contaminated clothing, wash skin with plenty of soap and water, do not reuse clothing until laundered
Eye Contact: Rinse with water for at least 15 minutes, remove contact lenses, keep eyelids open, seek medical help if irritation persists
Ingestion: Do not induce vomiting, rinse mouth, seek prompt medical attention, never give anything by mouth to an unconscious person
Note to Physician: Treat symptomatically and supportively, monitor respiratory and neurological status closely in acute cases.
Suitable Extinguishing Media: Use alcohol-resistant foam, carbon dioxide, dry chemical, or water spray; do not use direct water stream as it may spread fire
Specific Hazards: Vapors can form explosive mixtures with air, heavier-than-air vapors can travel to source of ignition, risk of flashback
Protective Equipment: Firefighters should wear full bunker gear and self-contained breathing apparatus; use water spray to cool exposed containers
Combustion Products: Produces carbon oxides, acrid smoke and fumes, and potentially hazardous decomposition materials.
Personal Precautions: Evacuate downwind area, isolate hazard zone, ventilate enclosed spaces, use personal protective equipment against vapors and contact
Environmental Precautions: Prevent run-off into sewers, storm drains, surface waters; notify local authorities if significant spill enters the environment
Methods for Clean Up: Absorb spill with inert, non-combustible material such as sand or earth, place in labeled waste container, ventilate spill area well, do not flush into drains or surface water
Mitigation Tips: Large spills may require foam to suppress vapor; barricade as needed until area is confirmed vapor-free and all cleanup equipment is decontaminated.
Handling: Avoid skin and eye contact, work in areas with good ventilation, keep away from open flames and hot surfaces, use spark-proof tools and explosion-proof equipment, never eat or drink in work areas
Storage: Store tightly closed in cool, dry, well-ventilated place, keep away from incompatible materials like oxidizers or acids, ground all equipment, segregate MEK from other flammable liquids to reduce fire risk, check storage area regularly for leaks or container bulging
Storage Temperatures: Keep below 35°C (95°F) for best stability and lowest vapor pressure, never freeze the product as this can compromise package integrity.
Occupational Exposure Limits: OSHA PEL: 200 ppm (TWA), ACGIH TLV: 200 ppm (TWA), 300 ppm (STEL)
Engineering Controls: Use local exhaust or general dilution ventilation, vapor-proof lighting and switches in hazardous areas, continuous air monitoring where spills are a concern
Personal Protective Equipment: Nitrile gloves, chemical splash goggles, flame-resistant lab coats or coveralls, face shields for large volumes, flame-proof shoes
Respiratory Protection: When adequate ventilation can't be assured, use NIOSH-approved air-purifying respirators for organic vapors; for large spills, full-face supplied-air respirators may be needed.
Hygiene Measures: Wash thoroughly after handling, keep work clothes separate from street clothes, clean PPE regularly, post hazard signs in storage and mixing areas.
Appearance: Colorless liquid
Odor: Sharp, sweet acetone-like smell
Odor Threshold: 5-25 ppm
pH: Not applicable (does not mix with water in ionic form)
Melting Point: -86°C (-123°F)
Boiling Point: 80°C (176°F)
Flash Point: -9°C (16°F), closed cup
Evaporation Rate: Approximately 2.7 (Butyl Acetate = 1)
Flammability: Highly flammable liquid and vapor
Vapor Pressure: 71 mmHg at 20°C (68°F)
Vapor Density: 2.41 (air = 1)
Relative Density: 0.805 (Water = 1)
Solubility in Water: 29 g/100 mL at 20°C
Partition Coefficient (n-octanol/water): 0.29
Auto-ignition Temperature: 404°C (759°F)
Decomposition Temperature: Not readily decomposed in ambient conditions
Viscosity: 0.43 mPa·s at 20°C
Chemical Stability: Stable under standard ambient conditions and recommended handling; instability can occur with exposure to strong oxidizers
Polymerization: Does not polymerize under typical usage
Conditions to Avoid: Flames, sparks, hot surfaces, direct sunlight for prolonged periods
Incompatible Materials: Strong acids, alkalis, oxidizers such as chlorine or peroxides, strong reducing agents, aluminum and magnesium at high temperatures
Decomposition Products: Heat or burning produces carbon oxides, irritating organic vapors, and acrid smoke.
Acute Toxicity: Oral LD50 (rat): 2,730 mg/kg; Inhalation LC50 (rat, 4hr): 11,700 ppm; Dermal LD50 (rabbit): >5,000 mg/kg
Skin and Eye Irritation: Causes irritation to eyes and moderate irritation to skin on repeated or prolonged exposure
Respiratory Effects: Inhalation can cause drowsiness, dizziness, headache, and, at high levels, central nervous system depression
Chronic Effects: Long-term exposure may cause liver and kidney injury, dermatitis from prolonged skin contact
Carcinogenicity: Not listed as a carcinogen by IARC, NTP, OSHA
Other Health Effects: Alcohol use may enhance toxic effects; MEK can increase risk from other hazardous solvents in the workplace, especially by amplifying their absorption and toxicity.
Ecotoxicity: Fish LC50 (pimephales promelas, 96hr): 3,220 mg/L; Daphnia EC50 (48hr): 3,520 mg/L; low toxicity to aquatic life in dilution but spills may cause localized environmental impact
Persistence and Degradability: Readily bio-degradable in air and water, half-life typically under 14 days for most environments
Bioaccumulation Potential: Low, as chemical breaks down quickly
Mobility in Soil: Highly mobile, can leach into groundwater if spilled in large amounts, especially on porous or sandy soils
Other Adverse Effects: Not a known ozone depleter, but volatile vapors can contribute to low-level photochemical smog.
Disposal Methods: Dispose in accordance with local, regional, and federal regulations; use a licensed hazardous waste contractor; never pour unused material down drain or on ground
Container Handling: Empty drums may retain hazardous residue, triple-rinse before recycling or disposal, do not weld or cut on used drums
Waste Codes: U159 (hazardous waste code for MEK in US), may vary by country
Special Instructions: Always keep waste containers tightly closed, properly labeled, and stored upright until removed for final disposal.
UN Number: UN1193
Proper Shipping Name: Methyl Ethyl Ketone
Hazard Class: 3 (Flammable Liquid)
Packing Group: II (medium danger)
Labels: Flammable liquid (red diamond)
Special Transport Precautions: Secure containers against movement, keep away from heat and ignition sources, transport only in approved containers, follow all DOT, IATA, IMDG guidelines (hazmat placards, documentation)
Road, air, or marine restrictions: Check with carrier and local rules for additional requirements, since MEK moves differently through metro tunnels, intermodal yards, and sea ports.
OSHA Status: Hazardous chemical under OSHA Hazard Communication Standard, 29 CFR 1910.1200
TSCA Inventory: Listed
EPA SARA Title III: Section 302: No; Section 313: Yes (Reportable)
CERCLA Reportable Quantity: 5,000 lbs. (2,270 kg)
RCRA Hazardous Waste: Yes, U159
California Prop 65: Not listed
Other Regulations: Subject to workplace right-to-know legislation in many states and provinces, check local, state, and federal regulations regularly since new rules or thresholds can show up with little warning.
