UN 3342 — Xanthates
Placard: Spontaneously Combustible. ERG Guide 135. Training/quick-reference only — use current ERG + SOP/SOG for incident-specific actions.
UN 3342 is Xanthates, a moisture-sensitive xanthate entry assigned to ERG Guide 135. Carbon disulfide release and re-ignition are key concerns.
Hazard overview: SPONTANEOUSLY COMBUSTIBLE/moisture-sensitive xanthate solid; may ignite or decompose when damp. Moisture or acids can release highly flammable and toxic carbon disulfide vapor. Dust can irritate eyes, skin and respiratory tract and spread contamination.
Response guidance: For UN 3342, isolate the area, keep material dry and use SCBA. Use compatible dry media only unless SDS/incident command confirms water compatibility.
Firefighter training notes: Training for UN 3342 should emphasize product verification, SCBA use, exposure control, decontamination, runoff containment and SDS/shipping paper review. Use ERG 135, SDS and local SOP.
Regulatory context: Xanthates is regulated as a hazardous material for transport and emergency response. Storage, reporting, exposure, waste and incident-notification duties depend on quantity, package type, formulation and jurisdiction; verify shipping papers, SDS and authority guidance.
Storage & handling: Xanthates should be stored dry in tightly closed compatible containers away from moisture, acids, oxidizers, heat and ignition sources. Keep compatible dry media available.
UN 3342 Quick Details
Common Hazards of UN 3342
- SPONTANEOUSLY COMBUSTIBLE/moisture-sensitive xanthate solid; may ignite or decompose when damp.
- Moisture or acids can release highly flammable and toxic carbon disulfide vapor.
- Dust can irritate eyes, skin and respiratory tract and spread contamination.
- May burn rapidly and re-ignite after apparent extinguishment.
- Fire may produce sulfur oxides, carbon disulfide and irritating/toxic smoke.
- Water or foam can worsen some reactions or spread contaminated residues.
- Exact xanthate salt, moisture content and stabilizer condition must be verified.
Chemical Identity & Physical Properties
Yellow to pale amber crystalline solids or powders with a characteristic unpleasant odor. Hygroscopic materials that may decompose in moist air.
| Also known as | XanthatesXanthic acid saltsDithiocarbonatesCellulose xanthateAlkyl xanthates |
| Appearance | Yellow to pale amber crystalline solids or powders with a characteristic unpleasant odor. Hygroscopic materials that may decompose in moist air. |
| Flash Point | Not applicable (spontaneously combustible solid) |
| Boiling Point | Not applicable (decomposes before boiling) |
| Vapor Density | Not applicable (solid) |
| Water Reactivity | Reacts with moisture and acids to release highly flammable carbon disulfide vapor; avoid water contact |
Fireground Response Guidance — UN 3342
Extinguishing Media
PPE Requirements
Use positive-pressure SCBA for dust, smoke or fire. Wear chemical-resistant gloves, eye/face protection and protective clothing; keep PPE dry where required.
Isolation & Evacuation
First Actions for a UN 3342 Incident
- Call 911 and the emergency response number on the shipping paper, if available.
- Keep unauthorized personnel away and establish incident command.
- Stay upwind, uphill and upstream.
- Avoid breathing vapor, dust, gas, mist, smoke or aerosols and avoid skin or eye contact.
- Keep moisture, acids, oxidizers and incompatible materials away until specialist guidance confirms compatibility.
- Do not touch damaged containers, cylinders, packages or spilled material without proper training and PPE.
- Prevent contaminated liquid, dust, runoff, residue and decontamination waste from spreading.
- Ventilate confined spaces only after monitoring and only if properly trained and equipped.
- Use ERG Guide 135, SDS, shipping papers and monitoring to set isolation, evacuation and entry decisions.
📋 Copy & Share Field Card
UN 3342 — XanthatesUse 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.