1,1,1-Trichloroethane (TCA / Methyl Chloroform) Storage & Tank Compatibility

Storing 1,1,1-Trichloroethane (TCA / Methyl Chloroform)? Start Here

1,1,1-Trichloroethane (TCA), widely known as methyl chloroform, is a colorless chlorinated solvent with the formula _C2H3Cl3 and a sweet, chloroform-like odor. Historically valued as a low-flammability cleaning and degreasing solvent for metal parts, electronics, and adhesives, it is denser than water and essentially insoluble in it. Because it is an ozone-depleting substance, its production has been phased out under the Montreal Protocol, but residual industrial use and remediation handling continue. For storage and handling, the key engineering fact is that TCA is a halogenated hydrocarbon: it readily permeates and swells polyolefins. It must be kept dry and inhibited, since contact with moisture can hydrolyze the solvent into corrosive hydrochloric acid. Material selection should favor fluoropolymers and properly inhibited metals rather than plastic tanks.

Is 1,1,1-Trichloroethane Compatible with Polyethylene (HDPE / XLPE) Tanks?

No. 1,1,1-Trichloroethane is not recommended for storage in polyethylene tanks. As a chlorinated hydrocarbon solvent, TCA is absorbed into the polyethylene matrix, causing the wall to swell, soften, lose mechanical strength, and become prone to environmental stress cracking. The solvent also permeates through the wall over time, leading to weight loss, vapor escape, and eventual failure. This applies to both standard high-density polyethylene (HDPE) and cross-linked polyethylene (XLPE); cross-linking improves stress-crack resistance but does not make polyethylene a barrier to chlorinated solvents. Polypropylene is likewise unsuitable. For bulk TCA, use fluoropolymer-lined or fluoropolymer (PVDF/PTFE) equipment, or dry and inhibited stainless steel. If a polyethylene tank previously held water-based chemistry, do not repurpose it for chlorinated solvent service.

Material compatibility at a glance

1,1,1-Trichloroethane is a chlorinated hydrocarbon solvent and is not compatible with polyethylene (HDPE or XLPE) or polypropylene, which absorb the solvent, swell and stress-crack. Specify fluoropolymers (PVDF, PTFE), fluoroelastomers (Viton/FKM), or dry, inhibited stainless or carbon steel. Keep the solvent dry and stabilized, because hydrolysis can generate hydrochloric acid that attacks metals.

Ratings: S suitable · C conditional / limited · U unsuitable. Verify against the cited resistance charts and your concentration/temperature before specifying.

The safety that actually matters

• Keep away from heat, sparks, open flame and hot surfaces; although the liquid is hard to ignite, vapors can burn and thermal decomposition produces toxic and corrosive fumes including hydrogen chloride and phosgene.
• Provide adequate ventilation; vapors are heavier than air and can accumulate in low or confined areas, causing drowsiness, dizziness and central nervous system depression.
• Wear chemically resistant gloves and splash goggles; the solvent defats skin and causes irritation, and is a suspected carcinogen and reproductive hazard.
• Store dry and stabilized; moisture can hydrolyze TCA to hydrochloric acid, which corrodes metals and degrades the product.
• Prevent release to the environment; the material is very toxic to aquatic life and is an ozone-depleting substance subject to regulatory control.
• Use only fluoropolymer, fluoroelastomer, or inhibited-metal containment and seals; never store in polyethylene or polypropylene vessels.

Common questions

Can I store 1,1,1-trichloroethane in an HDPE or XLPE tank?

No. TCA is a chlorinated solvent that polyethylene absorbs; the tank wall swells, softens and stress-cracks, and the solvent permeates through. Use fluoropolymer (PVDF/PTFE) or dry, inhibited stainless steel instead.

Is 1,1,1-trichloroethane flammable?

It is difficult to ignite as a liquid, with a flash point above 200 deg F, and is often described as a low-flammability solvent. However, its vapors can burn and it decomposes at high temperature into toxic and corrosive gases, so it must still be kept away from heat and ignition sources.

Why must TCA be kept dry and inhibited?

In the presence of water, TCA can hydrolyze and form hydrochloric acid, which corrodes metals and degrades the solvent. Commercial grades are sold with stabilizer (inhibitor) packages, and containment should exclude moisture.

What is the NFPA 704 rating for 1,1,1-trichloroethane?

Per NOAA CAMEO Chemicals and the OSHA chemical database, the NFPA 704 ratings are Health 2, Flammability 1, and Instability 0, with no special symbol.