☣️ UN 3099 • CLASS 5
UN 3099 — Oxidizing liquid, poisonous, n.o.s.
Placard: Oxidizer. ERG Guide 142. 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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UN 3099 Quick Details
UN 3099
Product name: Oxidizing liquid, poisonous, n.o.s.
DOT Class: 5
Placard type: Oxidizer
ERG Guide: 142 (check current ERG)
Initial isolation: ERG 142: Small spill isolate 50m all directions; Large spill isolate 150m all directions; Fire: evacuate 800m downwind
Common Hazards of UN 3099
- These substances will accelerate burning when 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.
- TOXIC; inhalation, ingestion or contact (skin, eyes) with vapors or substance may cause severe injury,
- Fire may produce irritating, corrosive and/or toxic gases.
Chemical Identity & Physical Properties
| Also known as | Oxidizing liquid, toxic, n.o.s.Oxidising liquid, poisonous, n.o.s.Oxidising liquid, toxic, n.o.s.Class 5.1 oxidizer with toxic properties |
| Appearance | Liquid oxidizers with toxic properties; specific appearance varies by composition. May range from colorless to colored liquids depending on the specific oxidizing agent; often has a pungent or irritating odor. |
| Flash Point | Not applicable (oxidizer) |
| Boiling Point | Varies by specific substance |
| Vapor Density | Varies by specific substance |
| Water Reactivity | May react with water depending on specific oxidizer; some release toxic or corrosive gases |
Chemical details are general reference only. Always verify with current SDS, ERG, and SOP/SOG.
Fireground Response Guidance — UN 3099
Extinguishing Media
Dry chemical, CO2; avoid organic foam materials; water spray for cooling only from safe distance
PPE Requirements
⚠️ Level B minimum with SCBA required; full chemical-resistant suit for spill response; avoid all contact due to combined oxidizing and toxic hazards
Isolation & Evacuation
ERG 142: Small spill isolate 50m all directions; Large spill isolate 150m all directions; Fire: evacuate 800m downwind
Always confirm protective actions with the current edition of the Emergency Response Guidebook (ERG Guide 142).
First Actions for a UN 3099 Incident
- 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 for at least 50 meters (150 feet) in all directions.
- For highlighted materials: see Table 1 - Initial Isolation and Protective Action Distances.
- For non-highlighted materials: increase the immediate precautionary measure distance, in the downwind
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UN 3099 — Oxidizing liquid, poisonous, n.o.s.HAZMAT RADIO NOTE — UN 3099
Product: Oxidizing liquid, poisonous, n.o.s.
Class 5 / Oxidizer / ERG 142
PPE: Level B minimum with SCBA required; full chemical-resistant suit for spill response; avoid all contact due to combined oxidizing and toxic hazards
ISOLATION: ERG 142: Small spill isolate 50m all directions; Large spill isolate 150m all directions; Fire: evacuate 800m downwind
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 3099 — Oxidizing liquid, poisonous, n.o.s.
Class: 5 | Placard: Oxidizer | ERG Guide: 142
Appearance: Liquid oxidizers with toxic properties; specific appearance varies by composition. May range from colorless to colored liquids depending on the specific oxidizing agent; often has a pungent or irritating odor.
Water Reactivity: May react with water depending on specific oxidizer; some release toxic or corrosive gases
Extinguishing: Dry chemical, CO2; avoid organic foam materials; water spray for cooling only from safe distance
PPE: Level B minimum with SCBA required; full chemical-resistant suit for spill response; avoid all contact due to combined oxidizing and toxic hazards
Isolation: ERG 142: Small spill isolate 50m all directions; Large spill isolate 150m all directions; Fire: evacuate 800m downwind
— Key Hazards —
• These substances will accelerate burning when involved in a fire.
• May explode from heat or contamination.
• Some will react explosively with hydrocarbons (fuels).
— 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/3099 | Always use current ERG + SOP/SOGIC BRIEFING
Use for: Incident command briefing, staging area whiteboard, or pre-entry team brief. Full chemical + response details.
UN3099 Oxidizing liquid, poisonous, n.o.s. Cls5 ERG142 | allfirefighter.com/hazmat/un/3099SMS / 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/3099
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Frequently Asked Questions about UN 3099
These substances will accelerate burning when 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. TOXIC; inhalation, ingestion or contact (skin, eyes) with vapors or substance may cause severe injury, Fire may produce irritating, corrosive and/or toxic gases.
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 with SCBA required; full chemical-resistant suit for spill response; avoid all contact due to combined oxidizing and toxic hazards
Water reactivity: May react with water depending on specific oxidizer; some release toxic or corrosive gases. Recommended extinguishing: Dry chemical, CO2; avoid organic foam materials; water spray for cooling only from safe distance.
ERG Guide 142 recommendation: ERG 142: Small spill isolate 50m all directions; Large spill isolate 150m all directions; Fire: evacuate 800m downwind
No. This is a training/quick-reference aid only. Always consult the current ERG Guide 142 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.