UN 1476 — Magnesium peroxide
Placard: Oxidizer. ERG Guide 140. Training/quick-reference only — use current ERG + SOP/SOG for incident-specific actions.
UN 1476 is Magnesium peroxide, a Class 5 peroxide oxidizer assigned to ERG Guide 140. It can release oxygen or alkaline/corrosive products and intensify nearby fires.
Hazard overview: UN 1476 presents oxidizer, oxygen-release and decomposition hazards. Heat, moisture, contamination or fuels can increase fire intensity and runoff may become alkaline or contaminated.
Response guidance: For a UN 1476 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 1476 should emphasize peroxide oxygen release, contamination control, incompatibility with fuels or organics, heating/decomposition behavior and correct extinguishing decisions. Use ERG 140, SDS and local SOP.
Regulatory context: Magnesium peroxide 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: Magnesium peroxide 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 1476 Quick Details
Common Hazards of UN 1476
- 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 may release oxygen or alkaline/corrosive 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 to off-white odorless powder or granular solid at room temperature. May appear yellowish when impure.
| Also known as | Magnesium dioxideMagnesium superoxidePeroxide of magnesiumMagnesium peroxide hydrate |
| CAS Number | 1335-26-8 |
| Appearance | White to off-white odorless powder or granular solid at room temperature. May appear yellowish when impure. |
| Flash Point | Not applicable (oxidizing solid, non-flammable but accelerates combustion) |
| Boiling Point | Not applicable (decomposes before boiling at approximately 100C/212F) |
| Vapor Density | Not applicable (solid material) |
| Water Reactivity | Reacts with water to release oxygen gas and form magnesium hydroxide; reaction is not violent but generates heat |
Fireground Response Guidance — UN 1476
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 1476 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 1476 — Magnesium peroxideUse 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.