UN 1834 — Sulphuryl chloride
Placard: Toxic. ERG Guide 137. Training/quick-reference only — use current ERG + SOP/SOG for incident-specific actions.
UN 1834 is Sulphuryl chloride, a toxic corrosive fuming liquid assigned to ERG Guide 137. Water or moist air can trigger heat release and corrosive gas formation.
Hazard overview: UN 1834 presents water-reactive toxic/corrosive fume, heavy vapor and acidic-runoff hazards. Avoid water and foam directly on product unless specialist guidance confirms a safe use.
Response guidance: For a UN 1834 incident, responders should verify the product with shipping papers, package markings, SDS and ERG Guide 137. Establish incident command, isolate the area, stay upwind, prevent incompatible contact, control runoff and choose entry or fire-control actions based on monitoring, SDS and local SOP.
Firefighter training notes: Training for UN 1834 should emphasize water-reactive fuming liquid behavior, dense acid vapor clouds, dry-agent selection, downwind control, PPE selection and decontamination. Use ERG 137, SDS and local hazmat SOP.
Regulatory context: Sulphuryl chloride 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 concentration, formulation, 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: Sulphuryl chloride should be stored in tightly closed compatible containers in a cool, dry, well-ventilated area away from water, moisture, bases, oxidizers/reducing agents where incompatible, heat and unauthorized access. Protect containers from corrosion, leakage and contamination.
UN 1834 Quick Details
Common Hazards of UN 1834
- TOXIC and CORROSIVE fuming liquid; inhalation, ingestion or contact may cause severe injury.
- Reacts violently with water or moist air, releasing heat and hydrogen chloride and sulfur dioxide.
- Vapors are heavier than air and may collect in low or confined areas.
- Liquid and fumes can burn eyes, skin and respiratory tissue.
- Fire may produce irritating, corrosive and/or toxic gases.
- Runoff may spread acidic and toxic contamination.
- Containers may rupture or fail when heated or contaminated with water.
Chemical Identity & Physical Properties
Colorless to pale yellow fuming liquid with a pungent, irritating odor. Fumes in moist air due to hydrolysis.
| Also known as | Sulfuryl chlorideSulfonyl chlorideSulfuric oxychlorideSO2Cl2 |
| CAS Number | 7791-25-5 |
| Appearance | Colorless to pale yellow fuming liquid with a pungent, irritating odor. Fumes in moist air due to hydrolysis. |
| Flash Point | Not applicable (non-flammable) |
| Boiling Point | 69C (156F) |
| Vapor Density | 4.7 (much heavier than air) |
| Water Reactivity | Reacts violently with water producing hydrochloric acid and sulfuric acid with heat generation and toxic fumes |
Fireground Response Guidance — UN 1834
Extinguishing Media
PPE Requirements
Use positive-pressure SCBA for vapor, fume, fire or confined-space exposure. Chemical-resistant gloves, boots, eye/face protection and protective clothing should be selected from SDS; Level A may be needed for close entry or unknown concentrations.
Isolation & Evacuation
First Actions for a UN 1834 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 or spray and avoid skin or eye contact.
- Keep water and moisture away from released product unless incident command confirms a compatible cooling or control use.
- 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, water reaction or unknown concentration is present.
- Use ERG Guide 137, shipping papers, SDS, air monitoring and incident command for protective actions.
📋 Copy & Share Field Card
UN 1834 — Sulphuryl chlorideUse 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.