UN 1848 — Propionic acid, with not less than 10% and less than 90% acid
Placard: Corrosive. ERG Guide 153. Training/quick-reference only — use current ERG + SOP/SOG for incident-specific actions.
UN 1848 is Propionic acid, with not less than 10% and less than 90% acid, a Class 8 corrosive liquid assigned to ERG Guide 153. It is a propionic acid solution that can cause skin, eye and respiratory injury and may present combustible vapor hazards when heated.
Hazard overview: UN 1848 presents a corrosive liquid hazard with added combustible vapor concerns. Contact can burn or severely irritate skin and eyes, while vapors or mist may irritate the respiratory tract. Fire or heat may produce irritating, corrosive or toxic gases, and heated vapors can form explosive mixtures in confined spaces or sewers.
Response guidance: For a UN 1848 incident, responders should confirm the concentration and product identity using shipping papers, container markings, SDS and ERG Guide 153. Establish incident command, isolate the area, keep personnel upwind and uphill, avoid contact with liquid or vapor, control ignition sources, and contain corrosive runoff when safe under local SOP.
Firefighter training notes: Training should emphasize corrosive liquid contact hazards, combustible vapor behavior, sewer flashback potential and concentration verification for propionic acid solutions. Common tactical errors include treating diluted acid as harmless, ignoring ignition sources, entering low areas where vapors may collect and allowing corrosive runoff into drains. Incident command should coordinate isolation, vapor monitoring, spill control, decontamination and runoff management under local SOP.
Regulatory context: Propionic acid solution under UN 1848 is regulated as a Class 8 corrosive hazardous material for transportation and emergency response purposes. Workplace exposure, spill reporting, waste handling and environmental controls may apply depending on concentration, quantity and jurisdiction. Responders should verify current requirements through shipping papers, SDS, facility documents and applicable DOT, OSHA, EPA, state or local authority guidance.
Storage & handling: Propionic acid solution should be stored in tightly closed compatible containers in a cool, dry and well-ventilated area. Keep it away from strong oxidizers, strong bases, incompatible metals, ignition sources and heat. Storage areas should include corrosion-compatible containment and controls to prevent leaks from reaching drains or waterways.
UN 1848 Quick Details
Common Hazards of UN 1848
- TOXIC and/or CORROSIVE; inhalation, ingestion or skin contact with material may cause severe injury.
- Avoid skin and eye contact; propionic acid solutions can cause chemical burns and severe irritation.
- Fire may produce irritating, corrosive and/or toxic gases.
- Runoff from fire control or dilution water may be corrosive or toxic and may cause environmental contamination.
- Combustible liquid: may burn but does not ignite readily under normal conditions.
- When heated, vapors may form explosive mixtures with air, especially in confined spaces, low areas or sewers.
- Vapors are heavier than air and may travel along the ground to ignition sources.
- Contact with some metals may generate flammable hydrogen gas.
Chemical Identity & Physical Properties
Propionic acid solution is typically a clear, colorless liquid with a strong pungent, rancid odor. It is miscible with water, has heavier-than-air vapors, and may burn under fire or high-heat conditions.
| Also known as | Propanoic acidMethylacetic acidEthanecarboxylic acidCarboxyethane |
| CAS Number | 79-09-4 |
| Appearance | Clear, colorless 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 | Soluble in water; exothermic dissolution may generate heat but no violent reaction |
Fireground Response Guidance — UN 1848
Extinguishing Media
PPE Requirements
Responders should use positive-pressure SCBA when vapors, mist, fire gases or confined-space exposure may be present. Acid-resistant gloves, boots, eye/face protection and chemical-resistant clothing should be selected according to ERG 153, SDS, concentration, monitoring results and local SOP.
Isolation & Evacuation
First Actions for a UN 1848 Incident
- CALL 911. Then call the emergency response telephone number on the shipping paper, if available.
- Keep unauthorized personnel away.
- Stay upwind, uphill and/or upstream.
- Avoid breathing vapors, mist or fire gases.
- Do not touch damaged containers or spilled material unless properly trained and wearing appropriate protective equipment.
- Eliminate ignition sources if it is safe to do so.
- Ventilate closed spaces before entering, but only if properly trained, equipped and authorized by incident command.
- Isolate the spill or leak area in all directions for at least 50 meters (150 feet) for liquids.
- For highlighted materials, consult ERG Table 1 for Initial Isolation and Protective Action Distances.
- For non-highlighted materials, increase the immediate precautionary distance as needed in the downwind direction based on conditions.
📋 Copy & Share Field Card
UN 1848 — Propionic acid, with not less than 10% 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.