UN 2720 — Chromium nitrate
Placard: Oxidizer. ERG Guide 141. Training/quick-reference only — use current ERG + SOP/SOG for incident-specific actions.
UN 2720 At a Glance
UN 2720 (Chromium nitrate) is listed as DOT Class 5 Oxidizer and is assigned to ERG Guide 141. Use this page to review placard data, common hazards, PPE notes, isolation context, first actions, and related UN numbers.
Chromium nitrate is an oxidizing chromium salt, often encountered as hydrated crystals. It can accelerate burning and create contaminated runoff.
Hazard overview: Chromium nitrate is an oxidizing solid. The main fire problem is intensification of burning when it contacts fuels or combustible contamination.
Response guidance: Remove combustibles from the area, keep contaminated runoff contained and cool exposed containers from a protected location. Do not let product mix with oils, fuels or organics.
Firefighter training notes: Train crews to identify Chromium nitrate by UN number, placard, ERG guide and SDS before choosing entry, isolation or extinguishment tactics.
Regulatory context: Use UN 2720, ERG 141, SDS, container labels and shipping papers to confirm the exact hazard profile and protective action distances.
Storage & handling: Store in closed, compatible containers away from heat, ignition sources and incompatible materials; keep the area ventilated and protected from damage.
UN 2720 Quick Details
Common Hazards of UN 2720
- Oxidizer; it can intensify fire even though the material itself is not fuel.
- Contact with combustibles, organics, oils, fuels or reducing agents may cause ignition or rapid burning.
- Fire may produce irritating and toxic fumes.
- Dust or solution contact may irritate skin, eyes and respiratory tract.
- Runoff can carry toxic metal or oxidizing contamination into waterways.
- Containers exposed to heat may rupture.
- Contamination can make the material unstable or more reactive.
Chemical Identity & Physical Properties
Purple to violet hygroscopic crystalline solid; commonly encountered as a hydrate and odorless.
| Also known as | Chromic nitrateChromium(III) nitrateChromium trinitrateNitric acid chromium(III) salt |
| CAS Number | 13548-38-4 |
| Appearance | Purple to violet crystalline solid or hygroscopic crystals. May be encountered as nonahydrate form. Odorless. |
| Flash Point | Not applicable (oxidizing solid) |
| Boiling Point | Decomposes at 100-125C (212-257F) |
| Vapor Density | Not applicable (solid) |
| Water Reactivity | Soluble in water with heat release during dissolution |
Fireground Response Guidance — UN 2720
Extinguishing Media
PPE Requirements
Use SCBA for fire or dust conditions with chemical-resistant gloves, eye protection and protective clothing.
Isolation & Evacuation
First Actions for a UN 2720 Incident
- Call 911 and the emergency response number shown on shipping papers or container documents.
- Keep unauthorized personnel away and establish an initial isolation perimeter.
- Stay upwind, uphill and upstream; avoid low areas where vapors or runoff may collect.
- Avoid breathing vapors, dust, smoke or mist and prevent skin and eye contact.
- Keep combustibles, fuels, organic material, oils and reducing agents away from the release area.
- Do not touch damaged containers or spilled material without appropriate chemical PPE.
- Ventilate confined spaces only when personnel are trained, monitored and properly equipped.
- Use ERG guidance, SDS, shipping papers and air monitoring before committing crews.
📋 Copy & Share Field Card
UN 2720 — Chromium nitrateUse 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.