UN 1492 — Potassium persulphate
Placard: Oxidizer. ERG Guide 140. Training/quick-reference only — use current ERG + SOP/SOG for incident-specific actions.
UN 1492 is Potassium persulphate, a Class 5 peroxide or persulfate oxidizer assigned to ERG Guide 140. It can release oxygen or reactive decomposition products and intensify nearby fires.
Hazard overview: UN 1492 presents oxidizer, oxygen-release and decomposition hazards. Heat, moisture, contamination or fuels can increase fire intensity and runoff may become contaminated or reactive.
Response guidance: For a UN 1492 incident, responders should verify the product with shipping papers, package markings, SDS and ERG Guide 140. Establish incident command, isolate the area, stay upwind, keep fuels and organics away, avoid contaminated absorbents and choose extinguishing or spill-control actions based on ERG, SDS and local SOP.
Firefighter training notes: Training for UN 1492 should emphasize oxygen-release/decomposition behavior, contamination control, incompatibility with fuels or organics, heating hazards and correct extinguishing decisions. Use ERG 140, SDS and local SOP.
Regulatory context: Potassium persulphate 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 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: Potassium persulphate should be stored in compatible oxidizer storage away from fuels, organic materials, reducing agents, acids where incompatible, heat, ignition sources and contamination. Keep containers closed, dry, clearly labeled and separated from combustible packaging or spilled residues.
UN 1492 Quick Details
Common Hazards of UN 1492
- OXIDIZER: may intensify fire and accelerate burning of combustible materials.
- May decompose with heat or contamination, increasing oxygen release and fire intensity.
- May ignite combustibles such as wood, paper, oil, clothing, packaging or contaminated absorbents.
- Peroxides and persulfates may release oxygen or reactive decomposition products when heated, wetted or contaminated.
- Containers may rupture or explode when heated.
- Fire may produce irritating and/or toxic gases.
- Runoff may spread oxidizing material and create fire, explosion or environmental hazards.
- Dust, solution or decomposition products may irritate or injure eyes, skin or respiratory tissue.
Chemical Identity & Physical Properties
White crystalline powder or granular solid, odorless. Stable at room temperature but decomposes when heated.
| Also known as | Potassium peroxydisulfateDipotassium persulfatePotassium peroxydisulphateAnthion |
| CAS Number | 7727-21-1 |
| Appearance | White crystalline powder or granular solid, odorless. Stable at room temperature but decomposes when heated. |
| Flash Point | Not applicable (oxidizing solid) |
| Boiling Point | Decomposes at approximately 100C (212F) before boiling |
| Vapor Density | Not applicable (solid) |
| Water Reactivity | Soluble in water; aqueous solutions may slowly decompose releasing oxygen |
Fireground Response Guidance — UN 1492
Extinguishing Media
PPE Requirements
Use positive-pressure SCBA for fire, dust, decomposition or confined-space exposure. Chemical-resistant gloves, eye/face protection and protective clothing should be selected from SDS and incident command.
Isolation & Evacuation
First Actions for a UN 1492 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.
- Keep combustibles, fuels, organics, reducing agents and contaminated materials away from the spill.
- Do not touch or walk through spilled material unless properly trained and wearing appropriate protective equipment.
- Avoid creating dust clouds and prevent runoff from contacting combustibles, drains or incompatible materials when possible.
- Ventilate closed spaces before entering, but only if properly trained, equipped and authorized by incident command.
- Isolate the spill or fire area and expand the perimeter if large quantities, contamination, heating or container involvement are present.
- Use ERG Guide 140, shipping papers, SDS and local SOP for protective actions and entry decisions.
📋 Copy & Share Field Card
UN 1492 — Potassium persulphateUse 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.