☣️ UN 2249 • CLASS 6
UN 2249 — Dichlorodimethyl ether, symmetrical
Placard: Toxic. ERG Guide 131. Training/quick-reference only — use current ERG + SOP/SOG for incident-specific actions.
🚒☣️
⚠️ This page is a quick-reference aid. For real incidents: stage upwind, isolate, deny entry, request Hazmat early, and consult the current ERG + SOP/SOG.
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UN 2249 Quick Details
UN 2249
Product name: Dichlorodimethyl ether, symmetrical
DOT Class: 6
Placard type: Toxic
ERG Guide: 131 (check current ERG)
Initial isolation: ERG 131: isolate spill 50m all directions; evacuate 800m downwind if large spill; treat as highly toxic cancer hazard
Common Hazards of UN 2249
- TOXIC; may be fatal if inhaled, ingested or absorbed through skin.
- Inhalation or contact with some of these materials will irritate or burn skin and eyes.
- Methyl chloroacetate (UN2295) is an eye irritant/lachrymator (causes flow of tears).
- Fire will produce irritating, corrosive and/or toxic gases.
- Vapors may cause dizziness or asphyxiation, especially when in closed or confined areas.
- Runoff from fire control or dilution water may cause environmental contamination.
- HIGHLY FLAMMABLE: Will be easily ignited by heat, sparks or flames.
- Vapors may form explosive mixtures with air.
Chemical Identity & Physical Properties
| Also known as | Bis(chloromethyl) etherBCMEChloromethyl ethersym-Dichloromethyl etherOxybis(chloromethane) |
| CAS Number | 542-88-1 |
| Appearance | Colorless to pale yellow liquid with a suffocating, irritating odor. Volatile at room temperature. |
| Flash Point | Not applicable (highly volatile, flammable liquid) |
| Boiling Point | 106C (223F) |
| Vapor Density | 3.9 (heavier than air) |
| Water Reactivity | Hydrolyzes slowly in water, releasing formaldehyde and hydrochloric acid |
Chemical details are general reference only. Always verify with current SDS, ERG, and SOP/SOG.
Fireground Response Guidance — UN 2249
Extinguishing Media
Alcohol-resistant foam, CO2, dry chemical; water spray to reduce vapors
PPE Requirements
⚠️ Level A required; SCBA mandatory; full chemical protective suit; extremely toxic carcinogen
Isolation & Evacuation
ERG 131: isolate spill 50m all directions; evacuate 800m downwind if large spill; treat as highly toxic cancer hazard
Always confirm protective actions with the current edition of the Emergency Response Guidebook (ERG Guide 131).
First Actions for a UN 2249 Incident
- CALL 911. Then call emergency response telephone number on shipping paper. If shipping paper
- 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 for at least 50 meters (150 feet) in all directions.
- For highlighted materials: see Table 1 - Initial Isolation and Protective Action Distances.
- For non-highlighted materials: increase the immediate precautionary measure distance, in the downwind
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📋 Copy & Share Field Card
UN 2249 — Dichlorodimethyl ether, symmetricalHAZMAT RADIO NOTE — UN 2249
Product: Dichlorodimethyl ether, symmetrical
Class 6 / Toxic / ERG 131
PPE: Level A required; SCBA mandatory; full chemical protective suit; extremely toxic carcinogen
ISOLATION: ERG 131: isolate spill 50m all directions; evacuate 800m downwind if large spill; treat as highly toxic cancer hazard
ACTION: Stage upwind · Isolate · Deny entry · Request HazmatRADIO
Use for: Quick radio or face-to-face size-up. Short, structured, field-ready.
=== IC HAZMAT BRIEFING ===
UN 2249 — Dichlorodimethyl ether, symmetrical
Class: 6 | Placard: Toxic | ERG Guide: 131
Appearance: Colorless to pale yellow liquid with a suffocating, irritating odor. Volatile at room temperature.
Water Reactivity: Hydrolyzes slowly in water, releasing formaldehyde and hydrochloric acid
Extinguishing: Alcohol-resistant foam, CO2, dry chemical; water spray to reduce vapors
PPE: Level A required; SCBA mandatory; full chemical protective suit; extremely toxic carcinogen
Isolation: ERG 131: isolate spill 50m all directions; evacuate 800m downwind if large spill; treat as highly toxic cancer hazard
— Key Hazards —
• TOXIC; may be fatal if inhaled, ingested or absorbed through skin.
• Inhalation or contact with some of these materials will irritate or burn skin and eyes.
• Methyl chloroacetate (UN2295) is an eye irritant/lachrymator (causes flow of tears).
— First Actions —
• CALL 911. Then call emergency response telephone number on shipping paper. If shipping paper
• Keep unauthorized personnel away.
• Stay upwind, uphill and/or upstream.
• Ventilate closed spaces before entering, but only if properly trained and equipped.
SOURCE: allfirefighter.com/hazmat/un/2249 | Always use current ERG + SOP/SOGIC BRIEFING
Use for: Incident command briefing, staging area whiteboard, or pre-entry team brief. Full chemical + response details.
UN2249 Dichlorodimethyl ether, symmetrical Cls6 ERG131 | allfirefighter.com/hazmat/un/2249SMS / 160 CHAR
Use for: Quick text to command or incoming units. Fits in a single SMS. Includes link to full page.
⚠️ Quick-reference only. Always use current ERG + SOP/SOG for incident-specific actions.
Page: https://allfirefighter.com/hazmat/un/2249
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Frequently Asked Questions about UN 2249
TOXIC; may be fatal if inhaled, ingested or absorbed through skin. Inhalation or contact with some of these materials will irritate or burn skin and eyes. Methyl chloroacetate (UN2295) is an eye irritant/lachrymator (causes flow of tears). Fire will produce irritating, corrosive and/or toxic gases. Vapors may cause dizziness or asphyxiation, especially when in closed or confined areas. Runoff from fire control or dilution water may cause environmental contamination. HIGHLY FLAMMABLE: Will be easily ignited by heat, sparks or flames. Vapors may form explosive mixtures with air.
CALL 911. Then call emergency response telephone number on shipping paper. If shipping paper Keep unauthorized personnel away. Stay upwind, uphill and/or upstream.
Level A required; SCBA mandatory; full chemical protective suit; extremely toxic carcinogen
Water reactivity: Hydrolyzes slowly in water, releasing formaldehyde and hydrochloric acid. Recommended extinguishing: Alcohol-resistant foam, CO2, dry chemical; water spray to reduce vapors.
ERG Guide 131 recommendation: ERG 131: isolate spill 50m all directions; evacuate 800m downwind if large spill; treat as highly toxic cancer hazard
No. This is a training/quick-reference aid only. Always consult the current ERG Guide 131 and your department SOP/SOG for incident-specific protective actions.
Sources (high level): DOT/PHMSA marking & class concepts + ERG usage principles.
This page does not reproduce ERG guide text—always consult the current ERG for incident-specific protective actions.