UN 2683 — Ammonium sulphide, solution
Placard: Corrosive. ERG Guide 132. Training/quick-reference only — use current ERG + SOP/SOG for incident-specific actions.
UN 2683 is Ammonium sulphide, solution, a corrosive flammable sulfide solution assigned to ERG Guide 132. Hydrogen sulfide release and flashback are key concerns.
Hazard overview: CORROSIVE and FLAMMABLE sulfide solution; vapors may ignite and form explosive mixtures with air. Can release toxic and flammable hydrogen sulfide, especially with acids or heating. Liquid and vapor can burn eyes, skin and respiratory tissue.
Response guidance: For UN 2683, isolate the area, avoid skin contact and use SCBA where dust, vapor, mist or fire is present. Control ignition or moisture hazards as applicable and contain toxic/corrosive runoff.
Firefighter training notes: Training for UN 2683 should emphasize toxic exposure routes, SCBA use, dust/vapor monitoring, fire behavior, decontamination, runoff containment and SDS verification. Use ERG 132, SDS and local SOP.
Regulatory context: Ammonium sulphide, solution is regulated as a hazardous material for transport and emergency response. Storage, exposure, spill reporting, waste and fire-code duties depend on quantity, concentration and jurisdiction; verify shipping papers, SDS and local authority requirements.
Storage & handling: Ammonium sulphide, solution should be stored in tightly closed compatible containers with ventilation, ignition control, sulfide/H2S planning and segregation from acids and oxidizers.
UN 2683 Quick Details
Common Hazards of UN 2683
- CORROSIVE and FLAMMABLE sulfide solution; vapors may ignite and form explosive mixtures with air.
- Can release toxic and flammable hydrogen sulfide, especially with acids or heating.
- Liquid and vapor can burn eyes, skin and respiratory tissue.
- Hydrogen sulfide is heavier than air and may collect in low or confined areas.
- Runoff may be alkaline/sulfide-contaminated and harmful to waterways.
- Fire may produce sulfur oxides, nitrogen compounds and toxic smoke.
- Containers may rupture or fail when heated.
Chemical Identity & Physical Properties
Yellow to orange liquid with a strong, offensive rotten egg odor (hydrogen sulfide smell). Solution typically contains 40-44% ammonium sulfide in water.
| Also known as | Ammonium sulfide solutionDiammonium sulfideAmmonium monosulfideAmmonium hydrogen sulfide solution |
| CAS Number | 12135-76-1 |
| Appearance | Yellow to orange liquid with a strong, offensive rotten egg odor (hydrogen sulfide smell). Solution typically contains 40-44% ammonium sulfide in water. |
| Flash Point | Varies by concentration, typically 30-40°C (86-104°F) for commercial solutions |
| Boiling Point | Decomposes before boiling, releases hydrogen sulfide gas above 40°C (104°F) |
| Vapor Density | Greater than 1 (heavier than air due to hydrogen sulfide and ammonia vapors) |
| Water Reactivity | Miscible with water but may release toxic hydrogen sulfide and ammonia vapors upon dilution or heating |
Fireground Response Guidance — UN 2683
Extinguishing Media
PPE Requirements
Use positive-pressure SCBA for vapor, mist, dust, fire or confined-space exposure. Wear chemical-resistant gloves, boots, eye/face protection and protective clothing.
Isolation & Evacuation
First Actions for a UN 2683 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.
- Eliminate ignition sources if this can be done safely.
- Avoid breathing vapor, dust, mist, smoke or fumes and avoid skin or eye contact.
- Do not touch damaged containers or spilled material without proper training and PPE.
- Prevent contaminated liquid, dust, runoff and decontamination waste from spreading.
- Ventilate confined spaces only after monitoring and only if properly trained and equipped.
- Use ERG Guide 132, SDS, shipping papers and monitoring to set isolation, evacuation and entry decisions.
📋 Copy & Share Field Card
UN 2683 — Ammonium sulphide, solutionUse 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.