Trichloroethylene

Classification

Skin irritation, Category 2; Eye irritation, Category 2A; Germ cell mutagenicity, Category 2; Carcinogenicity, Category 1B; STOT single exposure, Category 3 (drowsiness or dizziness); Hazardous to the aquatic environment, chronic Category 3. Supplier classifications vary somewhat; check your SDS.

Hazard statements

• H315 Causes skin irritation.
• H319 Causes serious eye irritation.
• H336 May cause drowsiness or dizziness.
• H341 Suspected of causing genetic defects.
• H350 May cause cancer.
• H412 Harmful to aquatic life with long-lasting effects.

Key precautionary statements

• P201 Obtain special instructions before use.
• P261 Avoid breathing vapors.
• P271 Use only outdoors or in a well-ventilated area.
• P273 Avoid release to the environment.
• P280 Wear protective gloves, protective clothing, eye protection and face protection.
• P302+P352 IF ON SKIN: Wash with plenty of water.
• P308+P313 IF exposed or concerned: Get medical advice or attention.
• P405 Store locked up.

OSHA general industry limits come from Table Z-2: 100 ppm TWA, a 200 ppm ceiling, and a 300 ppm peak allowed for no more than 5 minutes in any 2 hours. The OSHA construction and maritime PEL is 100 ppm TWA. NIOSH treats TCE as a potential occupational carcinogen and recommends the lowest feasible exposure; the NIOSH IDLH is 1,000 ppm. The ACGIH TLV is far lower than the OSHA PEL at 10 ppm TWA with a 25 ppm STEL. Cal/OSHA sets 25 ppm TWA, a 100 ppm STEL and a 300 ppm ceiling. EPA's December 2024 TSCA rule also sets its own exposure requirements for uses it still allows; see the regulations section.

• Appearance: Colorless liquid (sometimes dyed blue)
• Odor: Sweet, chloroform-like odor
• Molecular weight: 131.4
• Boiling point: 189°F (87°C)
• Freezing point: -99°F (-73°C)
• Flash point: None under normal test conditions; combustible but burns with difficulty
• Autoignition temperature: About 770–788°F (410–420°C)
• Explosive limits: LEL 8%, UEL 10.5% (at 77°F)
• Vapor pressure: 58 mmHg
• Vapor density: 4.5 (air = 1); vapors collect in low areas
• Specific gravity: 1.46 (sinks in water)
• Water solubility: 0.1%

Inhalation

Causes headache, dizziness, drowsiness, visual disturbances, tremor, nausea and vomiting; high levels can cause loss of consciousness. TCE can trigger irregular heart rhythms, which is one reason high exposures can be fatal. Vapors are heavy and build up in degreaser pits, tanks and other confined spaces.

Skin

Irritates the skin and can cause burns and dermatitis, with numbness or tingling reported after exposure.

Eyes

Causes eye irritation and burns.

Ingestion

Harmful if swallowed. Get medical attention immediately.

Target organs

Eyes, skin, respiratory system, heart, liver, kidneys, central nervous system

Long-term effects

TCE caused liver, kidney and lung cancer in animals. NIOSH lists it as a potential occupational carcinogen, ACGIH classes it A2 (suspected human carcinogen), and NTP lists it as reasonably anticipated to be a human carcinogen. Repeated exposure can damage the liver and nervous system. Its health effects and uses overlap with tetrachloroethylene and methylene chloride, the other common chlorinated solvents.

Gloves

The New Jersey Department of Health lists Silver Shield/4H, Viton and Barrier gloves, with more than 8 hours of breakthrough time. One supplier SDS reports 480 minutes for 0.7 mm fluorinated rubber (Viton). Common disposable gloves are not suitable. See hand protection.

Eyes and face

Chemical splash goggles; add a face shield for large transfers.

Respiratory

Enclose degreasers and use local exhaust ventilation first. NJDOH advises supplied-air respirators or SCBA above 10 ppm. Because NIOSH treats TCE as a carcinogen, it lists only pressure-demand SCBA or supplied air with escape backup at any detectable concentration, with organic vapor gas masks for escape only. See respiratory protection.

Clothing

Chemical-resistant clothing (for example Tychem F, BR, Responder or TK) where splashing is likely. Remove clothing that becomes wet or contaminated, and wash skin.

Store in tightly closed containers in a cool, dry, well-ventilated area, away from heat, light and the incompatible materials below. Ground and bond metal containers during transfer, because TCE can build up a static charge. Keep vapor degreasers covered and well maintained to limit emissions.

Keep away from

• Strong bases such as sodium hydroxide and potassium hydroxide, which can form spontaneously flammable dichloroacetylene
• Chemically active metals such as lithium, sodium and titanium, and powdered barium, beryllium and magnesium
• Strong acids such as nitric acid and sulfuric acid
• Epoxides, epichlorohydrin and isocyanates

• Evacuate the area and keep unprotected people out; vapors collect in low areas.
• Ventilate the area and eliminate ignition sources.
• Responders should wear supplied-air respirators or SCBA.
• Absorb with vermiculite, dry sand, earth or another inert material and place in sealed containers for disposal.
• Do not wash into sewers or drains.
• Waste is likely to be regulated as hazardous waste; check with your state environmental agency or EPA.
• For larger spills, refer to ERG Guide 160.

Suitable extinguishing media

• Dry chemical
• Carbon dioxide (CO₂)
• Alcohol-resistant foam
• Water spray to cool fire-exposed containers and reduce vapors

Special hazards

Hard to ignite, but can burn. In a fire or on hot surfaces it breaks down into highly toxic gases, including phosgene and hydrogen chloride (which forms hydrochloric acid with moisture). Containers may explode when heated. Firefighters should wear SCBA and full protective gear.

• OSHA Hazard Communication (29 CFR 1910.1200): Hazardous chemical; labels, safety data sheets and worker training required.
• OSHA Air Contaminants (29 CFR 1910.1000 Table Z-2): 100 ppm TWA; 200 ppm ceiling; 300 ppm peak (5 minutes in any 2 hours).
• EPA TSCA risk management rule (final December 2024): Prohibits TCE under TSCA, with time-limited exemptions and conditions for certain critical uses. The rule is being challenged in federal court, and EPA has extended or postponed several compliance dates since 2025. Check EPA's TCE risk management page for current requirements.
• CERCLA hazardous substance (40 CFR 302.4): Listed as "Ethene, trichloro-"; reportable quantity 100 lb (45.4 kg). RCRA waste code U228.
• DOT Hazardous Materials (49 CFR 172.101): UN1710 Trichloroethylene, Class 6.1, PG III.

• NIOSH Pocket Guide: Trichloroethylene
• OSHA Occupational Chemical Database: Trichloroethylene
• OSHA Annotated PELs: Table Z-2
• NJ Department of Health Hazardous Substance Fact Sheet: Trichloroethylene
• Sigma-Aldrich SDS: Trichloroethylene (133124)
• SBA Office of Advocacy: EPA extends deadlines for parts of TCE rule
• 40 CFR 302.4: CERCLA hazardous substances and reportable quantities