UN 3151 — Halogenated monomethyldiphenylmethanes, liquid
Placard: Miscellaneous. ERG Guide 171. Training/quick-reference only — use current ERG + SOP/SOG for incident-specific actions.
Halogenated monomethyldiphenylmethanes, liquid, is a toxic halogenated organic entry. The shipped material may be an isomer mixture, so SDS verification is important.
Hazard overview: The liquid can expose responders through contact, mist or vapor. Fire or high heat can generate toxic and corrosive decomposition products, and runoff can create persistent contamination concerns.
Response guidance: Isolate the spill, prevent runoff and avoid direct contact. Use foam, dry chemical or CO2 for fires as product-compatible, and use water spray mainly for cooling exposed containers from a distance.
Firefighter training notes: Train responders to control contaminated runoff and smoke exposure from halogenated organic liquids. Avoid assuming a single CAS-specific behavior for this plural entry.
Regulatory context: UN 3151 is a Class 6 toxic entry. Verify exact composition, environmental reporting requirements and waste handling rules from shipping papers, SDS and local regulations.
Storage & handling: Store in compatible sealed containers with secondary containment, away from heat, oxidizers and ignition sources. Keep out of drains and protect from container damage.
UN 3151 Quick Details
Common Hazards of UN 3151
- Toxic liquid; exposure may occur by inhalation, ingestion or skin contact depending on formulation.
- Heating or fire may produce irritating, toxic or corrosive halogenated decomposition products.
- Combustibility varies, but liquid may burn or support toxic smoke when heated.
- Vapors or mist may be heavier than air and collect in low or confined areas.
- Runoff can contaminate soil and waterways.
- Skin and eye contact should be avoided; some halogenated organics can be persistent contaminants.
- Exact isomer mixture and additives must be verified from SDS and shipping papers.
Chemical Identity & Physical Properties
Colorless to pale yellow oily liquid with mild aromatic odor. May be transported at elevated temperatures Appearance and odor may vary with the isomer mixture and formulation.
| Also known as | Halogenated diphenylmethaneChlorinated diphenylmethaneBrominated diphenylmethaneHalogenated benzyl toluene |
| Appearance | Colorless to pale yellow oily liquid with mild aromatic odor. May be transported at elevated temperatures. |
| Flash Point | 110-130C (230-266F) |
| Boiling Point | 280-320C (536-608F) |
| Vapor Density | 6-8 (heavier than air) |
| Water Reactivity | No significant reaction with water |
Fireground Response Guidance — UN 3151
Extinguishing Media
PPE Requirements
Use SCBA and chemical-resistant protective clothing for spill or fire response. Select glove and suit materials from the SDS because halogenated organics can permeate some materials.
Isolation & Evacuation
First Actions for a UN 3151 Incident
- Call 911 and the emergency response number shown on the shipping paper, if available.
- Keep unauthorized personnel away and establish incident command before close approach.
- Stay upwind, uphill and upstream; avoid low areas where vapors or gases may collect.
- Avoid breathing vapors, dust, mist or fire gases and avoid skin or eye contact.
- Do not touch damaged containers or spilled material without proper PPE and training.
- Ventilate confined spaces only if trained, equipped and authorized by incident command.
- Use ERG guidance, SDS, shipping papers and monitoring results for final protective actions.
📋 Copy & Share Field Card
UN 3151 — Halogenated monomethyldiphenylmethanes,Use 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.