UN 2670 — Cyanuric chloride
Placard: Corrosive. ERG Guide 157. Training/quick-reference only — use current ERG + SOP/SOG for incident-specific actions.
UN 2670 is Cyanuric chloride, a corrosive moisture-reactive solid assigned to ERG Guide 157. Water or humid air releases HCl fumes and heat.
Hazard overview: TOXIC and CORROSIVE moisture-reactive solid; dust or fumes can burn eyes, skin and respiratory tissue. Reacts with water or moist air, releasing hydrogen chloride fumes and heat. Fumes in humid air and can create acidic/corrosive runoff.
Response guidance: For UN 2670, isolate the spill, stay upwind and use SCBA with chemical protection. Control moisture contact, use dry compatible media and contain acidic runoff under SDS and ERG 157.
Firefighter training notes: Training for UN 2670 should emphasize moisture-reactive HCl fuming, dry media, SCBA entry, decontamination, acidic runoff control and SDS verification. Use ERG 157, SDS and local SOP.
Regulatory context: Cyanuric chloride 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: Cyanuric chloride should be stored dry in tightly closed compatible containers away from water, moisture, bases, amines, alcohols and unauthorized access. Provide secondary containment.
UN 2670 Quick Details
Common Hazards of UN 2670
- TOXIC and CORROSIVE moisture-reactive solid; dust or fumes can burn eyes, skin and respiratory tissue.
- Reacts with water or moist air, releasing hydrogen chloride fumes and heat.
- Fumes in humid air and can create acidic/corrosive runoff.
- Non-combustible, but heating can produce toxic/corrosive chloride and nitrogen-containing fumes.
- Vapors/fumes may accumulate in poorly ventilated or confined areas.
- Runoff may be acidic, corrosive and environmentally harmful.
- Avoid dust generation and direct water contact with released product.
Chemical Identity & Physical Properties
White crystalline solid or powder with a pungent, irritating odor. May appear as colorless to white crystals. Releases irritating fumes in moist air.
| Also known as | 2,4,6-Trichloro-1,3,5-triazineTrichloro-s-triazineCyanuric acid chlorides-Triazine trichlorideCyanurchlorid |
| CAS Number | 108-77-0 |
| Appearance | White crystalline solid or powder with a pungent, irritating odor. May appear as colorless to white crystals. Releases irritating fumes in moist air. |
| Flash Point | Not applicable (non-flammable solid) |
| Boiling Point | 190C (374F) - decomposes before boiling |
| Vapor Density | Not applicable (solid, but vapors heavier than air) |
| Water Reactivity | Reacts with water producing hydrochloric acid and cyanuric acid, generating heat and toxic/corrosive fumes. Avoid water contact. |
Fireground Response Guidance — UN 2670
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 2670 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, mist, smoke or fumes and avoid skin or eye contact.
- Keep water or moisture contact controlled because it can release hydrogen chloride fumes and heat.
- 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 157, SDS, shipping papers and monitoring to set isolation, evacuation and entry decisions.
📋 Copy & Share Field Card
UN 2670 — Cyanuric chlorideUse 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.