UN 3250 — Chloroacetic acid, molten
Placard: Toxic. ERG Guide 153. Training/quick-reference only — use current ERG + SOP/SOG for incident-specific actions.
UN 3250 Chloroacetic acid, molten is assigned to ERG Guide 153 for initial emergency response. Colorless to light brown crystalline solid at room temperature; hygroscopic with a pungent, acrid odor. When molten, appears as a clear to amber liquid. Verify the exact product from shipping papers and SDS before selecting tactics.
Hazard overview: Primary hazards: a toxic hazardous material that may be fatal by inhalation, ingestion or skin absorption. TOXIC and/or CORROSIVE; inhalation, ingestion or skin contact with material may cause severe injury. Methyl bromoacetate (UN2643) is an eye irritant/lachrymator (causes flow of tears).
Response guidance: For a UN 3250 incident, isolate the area, keep unauthorized personnel away, stay upwind/uphill and confirm the exact material from shipping papers and SDS. Use compatible extinguishing media and prevent contaminated runoff from entering waterways. Follow ERG Guide 153 and local incident command procedures.
UN 3250 Quick Details
Common Hazards of UN 3250
- TOXIC and/or CORROSIVE; inhalation, ingestion or skin contact with material may cause severe injury.
- Methyl bromoacetate (UN2643) is an eye irritant/lachrymator (causes flow of tears).
- Contact with molten substance may cause severe burns to skin and eyes.
- Avoid any skin contact.
- Fire may produce irritating, corrosive and/or toxic gases.
- Runoff from fire control or dilution water may be corrosive and/or toxic and cause environmental contamination.
- Combustible material: may burn but does not ignite readily.
- When heated, vapors may form explosive mixtures with air indoors, outdoors and in sewers.
Chemical Identity & Physical Properties
Colorless to light brown crystalline solid at room temperature; hygroscopic with a pungent, acrid odor. When molten, appears as a clear to amber liquid.
| Also known as | Monochloroacetic acidMCAChloroethanoic acidα-Chloroacetic acid |
| CAS Number | 79-11-8 |
| Appearance | Colorless to light brown crystalline solid at room temperature; hygroscopic with a pungent, acrid odor. When molten, appears as a clear to amber liquid. |
| Flash Point | 126C (259F) |
| Boiling Point | 189C (372F) |
| Vapor Density | 3.3 (heavier than air) |
| Water Reactivity | Soluble in water; hydrolyzes slowly to form hydrochloric acid and glycolic acid, corrosive solution |
Fireground Response Guidance — UN 3250
Extinguishing Media
PPE Requirements
Level B minimum with acid-resistant suit; SCBA required; thermal protection for molten material; avoid all skin contact
Isolation & Evacuation
First Actions for a UN 3250 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.
- Ventilate closed spaces before entering, but only if properly trained and equipped.
- Isolate spill or leak area in all directions for at least 50 meters (150 feet) for liquids and 25 meters (75 feet) for solids.
- For highlighted materials: see Table 1 - Initial Isolation and Protective Action Distances.
- For non-highlighted materials, increase the initial isolation distance in the downwind direction as needed.
📋 Copy & Share Field Card
UN 3250 — Chloroacetic acid, moltenUse 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.