UN 2225 — Benzenesulphonyl chloride
Placard: Corrosive. ERG Guide 156. Training/quick-reference only — use current ERG + SOP/SOG for incident-specific actions.
UN 2225 is Benzenesulphonyl chloride, a corrosive combustible chlorinated liquid assigned to ERG Guide 156. Moisture can release hydrogen chloride fumes and acidic runoff.
Hazard overview: CORROSIVE combustible chlorinated liquid; inhalation, ingestion or skin/eye contact may cause severe injury. Reacts with water or moist air to release hydrogen chloride fumes and heat. Vapors are heavier than air and may collect in low or confined areas.
Response guidance: For a UN 2225 incident, verify the product with shipping papers, container markings, SDS and ERG Guide 156. Establish incident command, isolate the area, stay upwind, control ignition or incompatibility hazards, prevent runoff, dust or vapor spread and base entry/fire-control actions on monitoring and local SOP.
Firefighter training notes: Training for UN 2225 should emphasize corrosive vapor/dust exposure, moisture reaction, acid runoff, container heating, PPE selection and decontamination. Use ERG 156, SDS and local SOP.
Regulatory context: Benzenesulphonyl chloride is regulated as a hazardous material for transportation and emergency response purposes. Storage, workplace exposure, emergency planning, spill reporting, waste handling and environmental requirements vary by exact product, concentration, quantity and jurisdiction. Verify current requirements through shipping papers, SDS, container markings and applicable DOT, OSHA, EPA, NFPA, state or local authority guidance.
Storage & handling: Benzenesulphonyl chloride should be stored in tightly closed compatible containers in a cool, dry, ventilated area away from water/moisture, bases, oxidizers/reducing agents where incompatible, heat and unauthorized access. Provide secondary containment and prevent humid air exposure.
UN 2225 Quick Details
Common Hazards of UN 2225
- CORROSIVE combustible chlorinated liquid; inhalation, ingestion or skin/eye contact may cause severe injury.
- Reacts with water or moist air to release hydrogen chloride fumes and heat.
- Vapors are heavier than air and may collect in low or confined areas.
- Combustible material: may burn but does not ignite readily.
- Fire may produce hydrogen chloride, phosgene-type gases and other toxic/corrosive decomposition products.
- Runoff may be acidic, toxic and corrosive.
- Containers may rupture or fail when heated or contaminated with water.
Chemical Identity & Physical Properties
Clear to pale yellow oily liquid with a pungent, irritating odor. Combustible but does not ignite readily at room temperature.
| Also known as | Benzenesulfonyl chloridePhenylsulfonyl chlorideBenzene sulfonyl chlorideBSC |
| CAS Number | 98-09-9 |
| Appearance | Clear to pale yellow oily liquid with a pungent, irritating odor. Combustible but does not ignite readily at room temperature. |
| Flash Point | 113C (235F) |
| Boiling Point | 251C (484F) |
| Vapor Density | 5.4 (heavier than air) |
| Water Reactivity | Reacts with water, releasing hydrogen chloride (HCl) gas — corrosive and toxic fumes. Reaction may be vigorous. |
Fireground Response Guidance — UN 2225
Extinguishing Media
PPE Requirements
Use positive-pressure SCBA for vapor, dust, mist, fire or confined-space exposure. Wear chemical-resistant gloves, boots, eye/face protection and protective clothing selected from SDS; Level A may be needed for heavy vapor or unknown concentrations.
Isolation & Evacuation
First Actions for a UN 2225 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, dust, mist, smoke or fumes and avoid skin or eye contact.
- Avoid unnecessary water contact with released product unless incident command confirms a compatible control use.
- Do not touch damaged containers or 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 release area and expand the perimeter for fire involvement, vapor spread, dust generation, water reaction or unknown product identity.
- Use ERG Guide 156, shipping papers, SDS, air monitoring and incident command for protective actions.
📋 Copy & Share Field Card
UN 2225 — Benzenesulphonyl 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.