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.
UN 3099 is Oxidizing liquid, poisonous, n.o.s., a broad toxic oxidizing liquid assigned to ERG Guide 142. Exposure and oxidizer contamination require control.
Hazard overview: OXIDIZING and TOXIC liquid, n.o.s.; exposure by inhalation, ingestion or skin contact may cause severe injury. Can intensify fire involving combustibles and incompatible materials. Contact with fuels, organics, oils or reducing agents may cause violent reaction or decomposition.
Response guidance: For UN 3099, isolate the area, remove combustibles/reducing agents and identify the exact oxidizer. Use compatible tactics and contain toxic/corrosive runoff under ERG 142.
Firefighter training notes: Training for UN 3099 should emphasize product verification, SCBA use, oxidizer/corrosive compatibility, vapor/dust monitoring, decontamination and runoff control. Use ERG 142, SDS and local SOP.
Regulatory context: Oxidizing liquid, poisonous, n.o.s. is regulated as a hazardous material for transport and emergency response. Storage, reporting, exposure, waste and incident-notification duties depend on quantity, formulation, temperature-control status and jurisdiction; verify shipping papers, SDS and authority guidance.
Storage & handling: Oxidizing liquid, poisonous, n.o.s. should be stored in compatible oxidizer/corrosive-rated containers away from combustibles, organics, fuels, reducing agents, heat and contamination.
UN 3099 Quick Details
Common Hazards of UN 3099
- OXIDIZING and TOXIC liquid, n.o.s.; exposure by inhalation, ingestion or skin contact may cause severe injury.
- Can intensify fire involving combustibles and incompatible materials.
- Contact with fuels, organics, oils or reducing agents may cause violent reaction or decomposition.
- Vapor or mist hazards depend on the exact toxic oxidizer.
- Fire may release toxic, corrosive and oxidizing gases.
- Runoff may be toxic, oxidizing and environmentally harmful.
- Exact chemical identity must be verified from SDS and shipping papers.
Chemical Identity & Physical Properties
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.
| 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 |
Fireground Response Guidance — UN 3099
Extinguishing Media
PPE Requirements
Use positive-pressure SCBA and chemical-resistant protective clothing. Level A or B may be needed for unknown product, heavy vapor, dust, splash or fuming risk.
Isolation & Evacuation
First Actions for a UN 3099 Incident
- Call 911 and the emergency response number on the shipping paper, if available.
- Keep unauthorized personnel away and establish incident command.
- Stay upwind, uphill and upstream.
- Avoid breathing vapor, dust, mist, smoke or fumes and avoid skin or eye contact.
- Keep combustibles, organics, fuels and reducing agents away from the oxidizer.
- Do not touch damaged containers or spilled material without proper training and PPE.
- Prevent contaminated liquid, dust, runoff and decontamination waste from spreading.
- Ventilate confined spaces only after monitoring and only if properly trained and equipped.
- Use ERG Guide 142, SDS, shipping papers and monitoring to set isolation, evacuation and entry decisions.
📋 Copy & Share Field Card
UN 3099 — Oxidizing liquid, poisonous, n.o.s.Use 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.