UN 1792 — Iodine monochloride, solid
Placard: Corrosive. ERG Guide 157. Training/quick-reference only — use current ERG + SOP/SOG for incident-specific actions.
UN 1792 is Iodine monochloride, solid, a toxic corrosive iodine halide solid assigned to ERG Guide 157. It fumes in moist air and can release corrosive hydrogen chloride and iodine-containing vapors.
Hazard overview: UN 1792 presents corrosive dust, toxic vapor, moisture reaction and contaminated-runoff hazards. Avoid water-based agents unless incident command and SDS confirm a safe use.
Response guidance: For a UN 1792 incident, responders should verify the product with shipping papers, package markings, SDS and ERG Guide 157. 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 1792 should emphasize corrosive exposure routes, water or oxidizer incompatibility where applicable, air monitoring, PPE selection, decontamination and runoff containment. Use ERG 157, SDS and local SOP.
Regulatory context: Iodine monochloride, 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: Iodine monochloride, solid should be stored in tightly closed compatible containers in a cool, dry, well-ventilated area away from water, moisture, bases, oxidizers/reducing agents where incompatible, heat and unauthorized access. Protect containers from corrosion, leakage and contamination.
UN 1792 Quick Details
Common Hazards of UN 1792
- TOXIC and CORROSIVE iodine halide solid; inhalation, ingestion or contact may cause severe injury.
- Reacts with water or moist air, releasing heat and corrosive hydrochloric/iodine-containing fumes.
- Dust or vapor can severely irritate or burn eyes, skin and respiratory tissue.
- Non-flammable, but heating or fire may produce toxic and corrosive gases.
- Runoff may spread corrosive iodine/halide contamination.
- Containers may rupture or fail when heated.
- Avoid dust generation and moisture contact.
Chemical Identity & Physical Properties
Red-brown to brownish-black crystalline solid with a pungent, irritating odor. Hygroscopic and fumes in moist air.
| Also known as | Iodine chlorideIodine(I) chlorideWijs' chlorideIClChloroiodine |
| CAS Number | 7790-99-0 |
| Appearance | Red-brown to brownish-black crystalline solid with a pungent, irritating odor. Hygroscopic and fumes in moist air. |
| Flash Point | Not applicable (non-flammable solid) |
| Boiling Point | 97.4C (207.3F) with decomposition |
| Vapor Density | Not applicable (solid, but vapors heavier than air when volatilized) |
| Water Reactivity | Reacts with water to release hydrochloric acid and hypoiodous acid fumes; generates heat and corrosive vapors |
Fireground Response Guidance — UN 1792
Extinguishing Media
PPE Requirements
Use positive-pressure SCBA for vapor, fume, fire or confined-space exposure. Chemical-resistant gloves, boots, eye/face protection and protective clothing should be selected from SDS; Level A may be needed for close entry or unknown concentrations.
Isolation & Evacuation
First Actions for a UN 1792 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.
- Keep water and moisture away from released product unless incident command confirms a compatible cooling or control use.
- 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 157, shipping papers, SDS, air monitoring and incident command for protective actions.
📋 Copy & Share Field Card
UN 1792 — Iodine monochloride, 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.