UN 2723 — Magnesium chlorate
Placard: Oxidizer. ERG Guide 140. Training/quick-reference only — use current ERG + SOP/SOG for incident-specific actions.
Magnesium chlorate is an oxidizing chlorate; heat, friction or contamination with organics can create a severe fire or explosion hazard.
Hazard overview: Magnesium chlorate should be treated as an oxidizing solid. It can make ordinary combustibles burn faster and may decompose violently if heated or contaminated.
Response guidance: Isolate the area, eliminate ignition sources and keep combustibles away. Use dry chemical or dry sand for small material fires when appropriate; cool exposed containers from a protected distance with water spray if it can be done safely.
UN 2723 Quick Details
Common Hazards of UN 2723
- Magnesium chlorate is an oxidizer; it can intensify burning even though the material itself is not a fuel.
- Heat, shock, friction or contamination may cause rapid decomposition or explosion.
- Keep away from fuels, oils, paper, wood, clothing and other organic or reducing materials.
- Containers may rupture or explode when heated in a fire.
- Dust, solution or decomposition fumes may irritate or injure the eyes, skin and respiratory tract.
- Fire may produce toxic or irritating metal oxide and nitrogen/chlorine oxide fumes.
- Runoff can spread oxidizer contamination and increase fire or environmental hazards.
Chemical Identity & Physical Properties
White to yellowish crystalline solid, odorless. Hygroscopic, usually exists as hexahydrate form
| Also known as | Magnesium chlorate hexahydrateChloric acid magnesium saltMagnesium dichlorate |
| CAS Number | 10326-21-3 |
| Appearance | White to yellowish crystalline solid, odorless. Hygroscopic, usually exists as hexahydrate form. |
| Flash Point | Not applicable (oxidizer) |
| Boiling Point | Decomposes at 120C (248F) |
| Vapor Density | Not applicable (solid) |
| Water Reactivity | Soluble in water, no violent reaction but releases heat |
Fireground Response Guidance — UN 2723
Extinguishing Media
PPE Requirements
Use SCBA for fire, dust or fume conditions with chemical-resistant clothing, gloves and eye protection; upgrade based on monitoring and SDS.
Isolation & Evacuation
First Actions for a UN 2723 Incident
- Call 911 and the emergency response number shown on the shipping papers.
- Keep unauthorized personnel away and deny entry to the spill or fire area.
- Stay upwind, uphill and upstream; avoid low areas where vapors or runoff may collect.
- Avoid breathing dust, vapor, mist or smoke; prevent skin and eye contact.
- Do not touch damaged containers or spilled material without appropriate PPE.
- Ventilate confined spaces only if personnel are trained, equipped and monitored.
- Use the ERG, SDS, shipping papers and air monitoring to set isolation, PPE and tactical decisions.
📋 Copy & Share Field Card
UN 2723 — Magnesium chlorateUse 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.