UN 2985 — Chlorosilanes, flammable, corrosive, n.o.s.
Placard: Flammable. ERG Guide 155. Training/quick-reference only — use current ERG + SOP/SOG for incident-specific actions.
Chlorosilanes, flammable, corrosive, n.o.s. covers variable chlorosilane materials. These products are moisture-sensitive corrosive liquids and may also be flammable, so the exact SDS and shipping papers must drive final decisions.
Hazard overview: The main hazards are corrosive hydrogen chloride fumes, heat from hydrolysis and flammable vapor or gas generation. Treat the entry as flammable and corrosive until the exact product is identified.
Response guidance: Isolate the area, eliminate ignition sources, keep the material dry and use dry chemical, carbon dioxide or dry sand from a protected position. Do not apply water directly to liquid chlorosilanes.
Firefighter training notes: Train responders to identify UN 2985 from shipping papers, confirm the SDS, choose PPE from monitoring results and avoid relying on generic placard information alone.
Regulatory context: UN 2985 is listed for transport under hazard class 3 with ERG Guide 155. Confirm packing group, quantity limits and any special provisions from current DOT/TDG/IMDG documents.
Storage & handling: Store only in approved, labeled containers or packaging. Keep incompatible materials separated, control ignition sources where applicable and protect packages from heat, damage and unauthorized access.
UN 2985 Quick Details
Common Hazards of UN 2985
- Broad chlorosilane entry: exact behavior depends on the specific compound and concentration.
- Reacts with water or moist air, generating heat and corrosive hydrogen chloride fumes.
- Vapors may be irritating or corrosive and can collect in low or confined areas.
- May be flammable; vapors can form ignitable mixtures and flash back to the source.
- Contact can cause serious skin, eye and respiratory tract injury.
- Containers may rupture when heated or contaminated with water.
- Runoff and contaminated absorbents can remain acidic and hazardous.
- Some formulations may release flammable hydrogen during hydrolysis.
Chemical Identity & Physical Properties
Typically colorless to pale yellow liquids with pungent, acrid odor. Fuming liquid that releases corrosive vapors on contact with moisture.
| Also known as | Chlorosilanes n.o.s.Flammable chlorosilanesCorrosive chlorosilanesOrganosilicon chlorides |
| Appearance | Typically colorless to pale yellow liquids with pungent, acrid odor. Fuming liquid that releases corrosive vapors on contact with moisture. |
| Flash Point | -18C to 10C (0F to 50F) depending on specific chlorosilane |
| Boiling Point | 30C to 150C (86F to 302F) depending on specific chlorosilane |
| Vapor Density | 3-6 (heavier than air, will collect in low areas) |
| Water Reactivity | Reacts violently with water, generating heat and corrosive hydrogen chloride gas. Do not use water directly on material. |
Fireground Response Guidance — UN 2985
Extinguishing Media
PPE Requirements
SCBA is required. Use Level A or Level B chemical protection based on vapor concentration, splash potential and monitoring results; turnout gear alone is not chemical protection.
Isolation & Evacuation
First Actions for a UN 2985 Incident
- Call 911 and the emergency response number listed on the shipping papers.
- Keep unauthorized personnel away and establish hot, warm and cold zones.
- Stay upwind, uphill and upstream; avoid low areas where vapors may collect.
- Avoid breathing vapors, fumes, dust or spray mist; prevent skin and eye contact.
- Do not touch damaged packages or containers without appropriate PPE and monitoring.
- Ventilate confined spaces only when personnel are trained, equipped and monitored.
- Use the ERG guide, SDS, shipping papers and product labels to confirm final tactics.
📋 Copy & Share Field Card
UN 2985 — Chlorosilanes, flammable, corrosive, n.oUse 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.