UN 3472 — Crotonic acid, liquid
Placard: Corrosive. ERG Guide 153. Training/quick-reference only — use current ERG + SOP/SOG for incident-specific actions.
UN 3472 At a Glance
UN 3472 (Crotonic acid, liquid) 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 3472 is Crotonic acid, liquid, a corrosive combustible organic acid assigned to ERG Guide 153. Heavy vapors, burns and acidic runoff require control.
Hazard overview: CORROSIVE combustible organic acid liquid; contact can burn eyes, skin and respiratory tissue. Combustible liquid; heated vapors may form ignitable mixtures with air. Vapors are heavier than air and may collect in low or confined areas.
Response guidance: For UN 3472, 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 3472 should emphasize exposure routes, SCBA use, vapor/dust monitoring, decontamination, runoff containment and SDS verification. Use ERG 153, SDS and local SOP.
Regulatory context: Crotonic acid, liquid 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: Crotonic acid, liquid should be stored in tightly closed compatible containers with ventilation, secondary containment, restricted access and SDS-based segregation from incompatible materials.
UN 3472 Quick Details
Common Hazards of UN 3472
- CORROSIVE combustible organic acid liquid; contact can burn eyes, skin and respiratory tissue.
- Combustible liquid; heated vapors may form ignitable mixtures with air.
- Vapors are heavier than air and may collect in low or confined areas.
- Can irritate skin, eyes and respiratory tract; concentrated contact may cause burns.
- Fire may produce carbon monoxide and irritating organic acid smoke.
- Runoff may be acidic, corrosive and harmful to waterways.
- Containers may rupture or fail when heated.
Chemical Identity & Physical Properties
Colorless to pale yellow liquid or crystalline solid (melts near room temperature at 72°C). Has a pungent, irritating odor.
| Also known as | trans-2-Butenoic acidβ-Methylacrylic acidtrans-Crotonic acid2-Butenoic acid |
| CAS Number | 3724-65-0 |
| Appearance | Colorless to pale yellow liquid or crystalline solid (melts near room temperature at 72°C). Has a pungent, irritating odor. |
| Flash Point | 88°C (190°F) |
| Boiling Point | 185°C (365°F) |
| Vapor Density | 3.0 (heavier than air) |
| Water Reactivity | Soluble in water; no violent reaction but solution is corrosive |
Fireground Response Guidance — UN 3472
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 3472 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 3472 — Crotonic acid, liquidUse 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.