UN 1912 — Methyl chloride and methylene chloride mixture
Placard: Flammable Gas. ERG Guide 115. Training/quick-reference only — use current ERG + SOP/SOG for incident-specific actions.
UN 1912 is Methyl chloride and methylene chloride mixture, a flammable liquefied gas mixture assigned to ERG Guide 115. It combines methyl chloride flammability with chlorinated solvent toxicity, so vapor control and ignition control both matter.
Hazard overview: UN 1912 presents flammable gas, toxic inhalation, heavy-vapor, flashback and cylinder rupture hazards. Fire may produce HCl and phosgene-type decomposition products.
Response guidance: For a UN 1912 incident, responders should verify the product with shipping papers, package markings, SDS and ERG Guide 115. Establish incident command, isolate the area, stay upwind, control ignition or incompatibility hazards, prevent runoff or vapor spread and choose entry/fire-control actions based on monitoring, SDS and local SOP.
Firefighter training notes: Training for UN 1912 should emphasize vapor travel, flashback, sewer explosion, foam selection, container cooling, ignition control and toxic exposure where applicable. Use ERG 115, SDS and local SOP.
Regulatory context: Methyl chloride and methylene chloride mixture is regulated as a hazardous material for transportation and emergency response purposes. Transportation, workplace exposure, spill reporting, waste handling, storage and environmental requirements may vary by formulation, concentration, quantity and jurisdiction. Verify current requirements through shipping papers, SDS, facility documents and applicable DOT, OSHA, EPA, NFPA, state or local authority guidance.
Storage & handling: Methyl chloride and methylene chloride mixture containers should be secured in a cool, ventilated area away from heat, flames, physical damage and incompatible materials. Gas storage should include leak control, ventilation and emergency planning appropriate to SDS and local code.
UN 1912 Quick Details
Common Hazards of UN 1912
- EXTREMELY FLAMMABLE liquefied gas mixture; vapors may ignite easily and form explosive mixtures with air.
- Contains toxic chlorinated components; inhalation may cause central nervous system effects and serious exposure.
- Vapors are heavier than air and can travel along the ground to ignition sources and flash back.
- Cylinders exposed to fire may vent flammable gas, rupture or rocket.
- Methylene chloride component may add toxic solvent exposure and decomposition hazards.
- Fire may produce hydrogen chloride, phosgene-type and other toxic/corrosive gases.
- Low areas, sewers and confined spaces can accumulate flammable/toxic vapor.
Chemical Identity & Physical Properties
Colorless liquid or compressed gas mixture with a faint sweet, chloroform-like odor. Physical state depends on pressure and composition ratio.
| Also known as | Chloromethane and dichloromethane mixtureMethyl chloride/methylene chloride blendR-40/R-30 mixture |
| Appearance | Colorless liquid or compressed gas mixture with a faint sweet, chloroform-like odor. Physical state depends on pressure and composition ratio. |
| Flash Point | -24C (-11F) typical for mixtures high in methyl chloride component |
| Boiling Point | Varies with composition; methyl chloride component: -24C (-11F), methylene chloride component: 40C (104F) |
| Vapor Density | 2.5-3.0 (heavier than air) - both components denser than air |
| Water Reactivity | No significant reaction with water, but both components have limited water solubility |
Fireground Response Guidance — UN 1912
Extinguishing Media
PPE Requirements
Use positive-pressure SCBA for all leak, vapor, fire or confined-space exposure. Wear flame-resistant protection and chemical protection selected by SDS; avoid low areas and treat vapor as both flammable and toxic.
Isolation & Evacuation
First Actions for a UN 1912 Incident
- CALL 911. Then call the emergency response telephone number on the shipping paper, if available.
- Keep unauthorized personnel away.
- Stay upwind, uphill and/or upstream.
- Avoid breathing vapors, fumes, dust, mist, smoke or gas and avoid skin or eye contact.
- Eliminate ignition sources if safe and keep vapors and runoff out of drains, sewers and low areas.
- Do not touch or walk through spilled material unless properly trained and wearing appropriate protective equipment.
- Ventilate closed spaces before entering, but only if properly trained, equipped, monitored and authorized by incident command.
- Isolate the spill or leak area and expand the perimeter if vapor, dust, fire involvement, gas accumulation or unknown concentration is present.
- Use ERG Guide 115, shipping papers, SDS, air monitoring and incident command for protective actions.
📋 Copy & Share Field Card
UN 1912 — Methyl chloride and methylene chloride mUse for: Quick radio or face-to-face size-up. Short, structured, field-ready.
Use for: Incident command briefing, staging area whiteboard, or pre-entry team brief.
Use for: Quick text to command or incoming units. Fits in a single SMS.