☣️ UN 3219 • CLASS 5
Nitrites, inorganic, aqueous solution, n.o.s.
Placard: Oxidizer. Training/quick-reference only — use current ERG + SOP/SOG for incident-specific actions.
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⚠️ This page is a quick-reference aid. For real incidents: stage upwind, isolate, deny entry, request Hazmat early, and consult the current ERG + SOP/SOG.
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Quick details
UN 3219
Class: 5
Placard type: Oxidizer
ERG: Guide 140 (check current ERG)
Isolation: ERG 140: isolate spill 50m all directions; if tank/rail car involved in fire, isolate 800m all directions and consider evacuation
Chemical & Response Details
| Also known as | Inorganic nitrite solutionNitrite salts in waterAqueous nitrite solutionNitrous acid salts solution |
| Appearance | Clear to slightly colored aqueous solution with little to no odor. Liquid at room temperature. Specific appearance depends on the nitrite salt dissolved. |
| Flash Point | Not applicable (non-flammable aqueous solution) |
| Boiling Point | Approximately 100C (212F), varies with concentration |
| Vapor Density | Not applicable (aqueous solution, vapor is primarily water) |
| Water Reactivity | Already in aqueous solution; may react with acids to release toxic nitrogen oxides |
| Extinguishing | Water spray, dry chemical, CO2. Avoid acidic extinguishing agents |
| PPE | ⚠️ Level B minimum; SCBA and chemical-resistant suit required; avoid skin contact as nitrites can be absorbed and cause methemoglobinemia |
| Isolation | ERG 140: isolate spill 50m all directions; if tank/rail car involved in fire, isolate 800m all directions and consider evacuation |
Chemical details are general reference only. Always verify with current SDS, ERG, and SOP/SOG.
Common hazards (high level)
- These substances will accelerate burning when involved in a fire.
- Some may decompose explosively when heated or involved in a fire.
- May explode from heat or contamination.
- Some will react explosively with hydrocarbons (fuels).
- May ignite combustibles (wood, paper, oil, clothing, etc.).
- Containers may explode when heated.
- Runoff may create fire or explosion hazard.
- Inhalation, ingestion or contact (skin, eyes) with vapors or substance may cause severe injury, burns or
First actions (field-minded)
- CALL 911. Then call emergency response telephone number on shipping paper. If shipping paper
- Keep unauthorized personnel away.
- Stay upwind, uphill and/or upstream.
- Ventilate closed spaces before entering, but only if properly trained and equipped.
- Isolate spill or leak area in all directions for at least 50 meters (150 feet) for liquids and at least 25 meters
- Consider initial downwind evacuation for at least 100 meters (330 feet).
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UN 3219 — Nitrites, inorganic, aqueous solution, n HAZMAT RADIO NOTE — UN 3219
Product: Nitrites, inorganic, aqueous solution, n.o.s.
Class 5 / Oxidizer / ERG 140
PPE: Level B minimum; SCBA and chemical-resistant suit required; avoid skin contact as nitrites can be absorbed and cause methemoglobinemia
ISOLATION: ERG 140: isolate spill 50m all directions; if tank/rail car involved in fire, isolate 800m all directions and consider evacuation
ACTION: Stage upwind · Isolate · Deny entry · Request HazmatRADIO
Use for: Quick radio or face-to-face size-up. Short, structured, field-ready.
=== IC HAZMAT BRIEFING ===
UN 3219 — Nitrites, inorganic, aqueous solution, n.o.s.
Class: 5 | Placard: Oxidizer | ERG Guide: 140
Appearance: Clear to slightly colored aqueous solution with little to no odor. Liquid at room temperature. Specific appearance depends on the nitrite salt dissolved.
Water Reactivity: Already in aqueous solution; may react with acids to release toxic nitrogen oxides
Extinguishing: Water spray, dry chemical, CO2. Avoid acidic extinguishing agents
PPE: Level B minimum; SCBA and chemical-resistant suit required; avoid skin contact as nitrites can be absorbed and cause methemoglobinemia
Isolation: ERG 140: isolate spill 50m all directions; if tank/rail car involved in fire, isolate 800m all directions and consider evacuation
— Key Hazards —
• These substances will accelerate burning when involved in a fire.
• Some may decompose explosively when heated or involved in a fire.
• May explode from heat or contamination.
— First Actions —
• CALL 911. Then call emergency response telephone number on shipping paper. If shipping paper
• Keep unauthorized personnel away.
• Stay upwind, uphill and/or upstream.
• Ventilate closed spaces before entering, but only if properly trained and equipped.
SOURCE: allfirefighter.com/hazmat/un/3219 | Always use current ERG + SOP/SOGIC BRIEFING
Use for: Incident command briefing, staging area whiteboard, or pre-entry team brief. Full chemical + response details.
UN3219 Nitrites, inorganic, aqueous solution, n.o.s. Cls5 ERG140 | allfirefighter.com/hazmat/un/3219SMS / 160 CHAR
Use for: Quick text to command or incoming units. Fits in a single SMS. Includes link to full page.
⚠️ Quick-reference only. Always use current ERG + SOP/SOG for incident-specific actions. Page: https://allfirefighter.com/hazmat/un/3219
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FAQ
These substances will accelerate burning when involved in a fire. Some may decompose explosively when heated or involved in a fire. May explode from heat or contamination. Some will react explosively with hydrocarbons (fuels). May ignite combustibles (wood, paper, oil, clothing, etc.). Containers may explode when heated. Runoff may create fire or explosion hazard. Inhalation, ingestion or contact (skin, eyes) with vapors or substance may cause severe injury, burns or
CALL 911. Then call emergency response telephone number on shipping paper. If shipping paper Keep unauthorized personnel away. Stay upwind, uphill and/or upstream.
Level B minimum; SCBA and chemical-resistant suit required; avoid skin contact as nitrites can be absorbed and cause methemoglobinemia
No. This is a training/quick-reference aid only. Always consult the current ERG Guide 140 and your department SOP/SOG for incident-specific protective actions.
Sources (high level): DOT/PHMSA marking & class concepts + ERG usage principles. This page does not reproduce ERG guide text—always consult the current ERG for incident-specific protective actions.