UN 0342 — Nitrocellulose, wetted
Placard: Explosive 1.3C. ERG Guide 112. Training/quick-reference only — use current ERG + SOP/SOG for incident-specific actions.
UN 0342, Nitrocellulose wetted, is a Class 1.3C explosive shipped as a white to slightly yellow fibrous or cotton-like solid saturated with water or alcohol to suppress its explosive sensitivity. If allowed to dry, it becomes highly susceptible to ignition and rapid deflagration, making moisture maintenance the single most critical factor in safe handling.
Hazard overview: UN 0342 presents a serious fire and burning hazard capable of producing intense heat and potential fragment projection, though it is not classified as a mass explosion risk. The primary danger escalates dramatically if the material loses its wetting agent, as dry nitrocellulose can ignite from friction, heat, or spark with little warning.
Response guidance: Responders must isolate the spill or leak area immediately for at least 500 meters in all directions per ERG Guide 112, and if the material is involved in fire, evacuate a 1600-meter radius. The sole approved suppression method is continuous water spray to maintain wet conditions; do not allow the material to dry under any circumstances, and avoid dry chemical or CO2 agents, which are ineffective once burning is established.
UN 0342 Quick Details
Common Hazards of UN 0342
- Fire and burning hazard — not mass explosion.
- Intense heat and possible fragment projection.
- May deflagrate and initiate other materials.
- Smoke and toxic combustion products.
Chemical Identity & Physical Properties
UN 0342 appears as a white to slightly yellow fibrous solid or cotton-like material that is odorless or carries a faint ether-like odor when wet, and is always shipped in a wetted state with water or alcohol to reduce its explosion hazard during transport.
| Also known as | Cellulose nitrateGuncottonPyroxylinCollodion cottonNitrocotton |
| CAS Number | 9004-70-0 |
| Appearance | White to slightly yellow fibrous solid or cotton-like material. Odorless or slight ether-like odor when wet. Shipped wetted with water or alcohol to reduce explosion hazard. |
| Flash Point | Not applicable (explosive solid, requires wetting agent) |
| Boiling Point | Not applicable (decomposes before boiling) |
| Vapor Density | Not applicable (solid) |
| Water Reactivity | No reaction with water; water is used as desensitizing wetting agent |
Fireground Response Guidance — UN 0342
Extinguishing Media
PPE Requirements
A minimum of Level B protection with full structural firefighter clothing and SCBA is required, with responders maintaining maximum safe standoff distance at all times due to the deflagration risk if the material has partially dried.
Isolation & Evacuation
First Actions for a UN 0342 Incident
- CALL 911. Then call emergency response telephone number on shipping paper.
- Isolate area; stage upwind — fire and fragment hazard.
- Request Hazmat + law enforcement.
- Control ignition sources; deny entry.
- Consult current ERG Guide 112 and follow SOP/SOG.
📋 Copy & Share Field Card
UN 0342 — Nitrocellulose, wettedUse 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.