UN 1845 — Carbon dioxide, solid
Placard: Miscellaneous. ERG Guide 120. Training/quick-reference only — use current ERG + SOP/SOG for incident-specific actions.
UN 1845 is Carbon dioxide, solid, a corrosive hazardous material assigned to ERG Guide 120. Responders should verify the exact product with shipping papers, package markings and SDS before close action.
Hazard overview: UN 1845 presents corrosive exposure hazards and may create toxic/corrosive gases or runoff in fire or incompatible contact. Use ERG, SDS and incident command to set isolation, PPE and control actions.
Response guidance: For a UN 1845 incident, responders should verify the product with shipping papers, package markings, SDS and ERG Guide 120. 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 1845 should emphasize corrosive/toxic exposure routes, water incompatibility where applicable, air monitoring, PPE selection, decontamination and runoff containment. Use ERG 120, SDS and local SOP.
Regulatory context: Carbon dioxide, solid 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: Carbon dioxide, solid should be stored in tightly closed compatible containers in a secure, cool, dry, well-ventilated hazardous-material area according to SDS and local procedures.
UN 1845 Quick Details
Common Hazards of UN 1845
- Hazards depend on the exact product, packaging and incident conditions.
- Verify the material using shipping papers, labels and SDS before close action.
- Fire may produce irritating or toxic smoke.
- Containers may fail or rupture when heated.
Chemical Identity & Physical Properties
White or colorless solid (snow-like or block form) that sublimates directly to gas at -78.5°C (-109.3°F). Odorless. Denser than air.
| Also known as | Dry iceSolid carbon dioxideCardiceCarbon dioxide snow |
| CAS Number | 124-38-9 |
| Appearance | White or colorless solid (snow-like or block form) that sublimates directly to gas at -78.5°C (-109.3°F). Odorless. Denser than air. |
| Flash Point | Not applicable (non-flammable) |
| Boiling Point | Not applicable (sublimes at -78.5°C/-109.3°F) |
| Vapor Density | 1.5 (heavier than air) |
| Water Reactivity | No significant reaction, but rapidly sublimates producing large volumes of CO2 gas |
Fireground Response Guidance — UN 1845
Extinguishing Media
PPE Requirements
Use protective equipment selected from SDS, monitoring results and incident command.
Isolation & Evacuation
First Actions for a UN 1845 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.
- 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 120, shipping papers, SDS, air monitoring and incident command for protective actions.
📋 Copy & Share Field Card
UN 1845 — Carbon dioxide, solidUse 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.