UN 3463 — Propionic acid, with not less than 90% acid
Placard: Corrosive. ERG Guide 153. Training/quick-reference only — use current ERG + SOP/SOG for incident-specific actions.
UN 3463 At a Glance
UN 3463 (Propionic acid, with not less than 90% acid) is listed as DOT Class 8 Corrosive and is assigned to ERG Guide 153. Use this page to review placard data, common hazards, PPE notes, isolation context, first actions, and related UN numbers.
UN 3463 is Propionic acid, with not less than 90% acid, a corrosive combustible organic acid assigned to ERG Guide 153. Vapor, burns and acidic runoff are key hazards.
Hazard overview: CORROSIVE organic acid liquid; contact can severely burn eyes, skin and respiratory tissue. Combustible liquid; heated vapors may form ignitable mixtures in confined or low areas. Mixes with water and may release heat during dilution.
Response guidance: For UN 3463, isolate the area, avoid skin contact and use SCBA where vapor, dust, mist or fire is present. Contain runoff and verify controls with SDS/ERG 153.
Firefighter training notes: Training for UN 3463 should emphasize exposure routes, SCBA use, vapor/dust monitoring, decontamination, runoff containment and SDS verification. Use ERG 153, SDS and local SOP.
Regulatory context: Propionic acid, with not less than 90% acid is regulated as a hazardous material for transport and emergency response. Storage, reporting, exposure, waste and incident-notification duties depend on quantity, concentration, formulation and jurisdiction; verify shipping papers, SDS and authority guidance.
Storage & handling: Propionic acid, with not less than 90% acid should be stored in tightly closed compatible containers with ventilation, secondary containment, restricted access and SDS-based segregation from incompatible materials.
UN 3463 Quick Details
Common Hazards of UN 3463
- CORROSIVE organic acid liquid; contact can severely burn eyes, skin and respiratory tissue.
- Combustible liquid; heated vapors may form ignitable mixtures in confined or low areas.
- Mixes with water and may release heat during dilution.
- Vapors are heavier than air and may collect near floors, pits or drains.
- Fire may produce carbon monoxide and irritating/corrosive organic acid smoke.
- Runoff may be acidic, corrosive and harmful to waterways.
- Containers may rupture or fail when heated.
Chemical Identity & Physical Properties
Colorless, oily liquid with a pungent, disagreeable rancid odor. Corrosive and miscible with water.
| Also known as | Propanoic acidEthylformic acidMethylacetic acidCarboxyethane |
| CAS Number | 79-09-4 |
| Appearance | Colorless, oily liquid with a pungent, disagreeable rancid odor. Corrosive and miscible with water. |
| Flash Point | 54°C (129°F) |
| Boiling Point | 141°C (286°F) |
| Vapor Density | 2.6 (heavier than air) |
| Water Reactivity | Miscible with water; generates heat upon mixing but no violent reaction |
Fireground Response Guidance — UN 3463
Extinguishing Media
PPE Requirements
Use positive-pressure SCBA for vapor, mist, fire or confined-space exposure. Wear chemical-resistant splash suit, gloves, boots and eye/face protection.
Isolation & Evacuation
First Actions for a UN 3463 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.
- Do not touch damaged containers, equipment 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 153, SDS, shipping papers and monitoring to set isolation, evacuation and entry decisions.
📋 Copy & Share Field Card
UN 3463 — Propionic acid, with not less than 90% aUse 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.