UN 2823 — Crotonic acid, solid
Placard: Corrosive. ERG Guide 153. Training/quick-reference only — use current ERG + SOP/SOG for incident-specific actions.
UN 2823 At a Glance
UN 2823 (Crotonic acid, solid) 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 2823 is Crotonic acid, solid, a corrosive organic acid assigned to ERG Guide 153. Burns, acidic runoff and combustible fire behavior require control.
Hazard overview: CORROSIVE organic acid; liquid, dust or vapor can burn eyes, skin and respiratory tissue. Combustible material: may burn but does not ignite readily. Water contact forms acidic solution; dilution can spread corrosive contamination.
Response guidance: For UN 2823, isolate the area, avoid skin contact and use SCBA where dust, vapor, mist or fire is present. Contain corrosive/toxic runoff and verify controls with SDS and ERG 153.
Firefighter training notes: Training for UN 2823 should emphasize exposure routes, SCBA use, vapor/dust monitoring, fire behavior, decontamination, runoff containment and SDS verification. Use ERG 153, SDS and local SOP.
Regulatory context: Crotonic acid, solid is regulated as a hazardous material for transport and emergency response. Storage, exposure, spill reporting, waste and fire-code duties depend on quantity, concentration and jurisdiction; verify shipping papers, SDS and local authority requirements.
Storage & handling: Crotonic acid, solid should be stored in tightly closed compatible containers with ventilation, secondary containment, restricted access and SDS-based segregation from incompatible materials.
UN 2823 Quick Details
Common Hazards of UN 2823
- CORROSIVE organic acid; liquid, dust or vapor can burn eyes, skin and respiratory tissue.
- Combustible material: may burn but does not ignite readily.
- Water contact forms acidic solution; dilution can spread corrosive contamination.
- Heated vapors may collect in low or confined areas and may ignite under fire conditions.
- Fire may produce carbon monoxide and irritating acidic smoke.
- Runoff may be acidic, corrosive and harmful to waterways.
- Containers may rupture or fail when heated.
Chemical Identity & Physical Properties
White to tan crystalline solid with a pungent, acrid odor. Melting point around 72°C (162°F), typically encountered as a solid at room temperature.
| Also known as | trans-2-Butenoic acidβ-Methylacrylic acidCrotonicum acidum(E)-2-Butenoic acidtrans-Crotonic acid |
| CAS Number | 3724-65-0 |
| Appearance | White to tan crystalline solid with a pungent, acrid odor. Melting point around 72°C (162°F), typically encountered as a solid at room temperature. |
| 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 forms acidic solution |
Fireground Response Guidance — UN 2823
Extinguishing Media
PPE Requirements
Use positive-pressure SCBA for vapor, dust, mist, fire or confined-space exposure. Wear chemical-resistant gloves, boots, eye/face protection and protective clothing.
Isolation & Evacuation
First Actions for a UN 2823 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 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 2823 — Crotonic acid, solidUse 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.