UN 3170 — Aluminum remelting by-products
Placard: Dangerous When Wet. ERG Guide 138. Training/quick-reference only — use current ERG + SOP/SOG for incident-specific actions.
UN 3170 is Aluminum remelting by-products, a dangerous-when-wet aluminum dross/by-product entry assigned to ERG Guide 138. Moisture can generate flammable gas.
Hazard overview: Aluminum remelting by-products can be dangerous when wet; contact with water may release flammable gas. May contain reactive metal fines, salts, oxides and dross residues that heat or react with moisture. Generated hydrogen, ammonia or other gases may ignite or create toxic exposure depending on composition.
Response guidance: For UN 3170, isolate the area, keep water/moisture away and use SCBA. Use compatible dry media only and monitor for flammable gas or re-ignition under ERG 138.
Firefighter training notes: Training for UN 3170 should emphasize dangerous-when-wet behavior, dry media, hydrogen monitoring, dust control, re-ignition and contaminated runoff. Use ERG 138, SDS and local SOP.
Regulatory context: Aluminum remelting by-products is regulated as a hazardous material for transport and emergency response. Storage, reporting, exposure, waste and incident-notification duties depend on quantity, package type, formulation and jurisdiction; verify shipping papers, SDS and authority guidance.
Storage & handling: Aluminum remelting by-products should be stored dry in compatible containers away from water, moisture, acids, oxidizers and ignition sources. Control dust and keep compatible dry media available.
UN 3170 Quick Details
Common Hazards of UN 3170
- Aluminum remelting by-products can be dangerous when wet; contact with water may release flammable gas.
- May contain reactive metal fines, salts, oxides and dross residues that heat or react with moisture.
- Generated hydrogen, ammonia or other gases may ignite or create toxic exposure depending on composition.
- Dust may irritate eyes and lungs and may contain metal contaminants.
- Water, foam or CO2 may worsen reactions or spread hot/reactive residues.
- Fire may produce metal oxide fumes and irritating/toxic smoke.
- Exact by-product composition and moisture condition must be verified.
Chemical Identity & Physical Properties
Gray to black solid residue material, often in powder or granular form. Byproduct from aluminum remelting operations containing metallic aluminum, aluminum oxide, salt flux residues, and other impurities.
| Also known as | Aluminum drossAluminum skimmingsAluminum processing by-productsAluminum smelting residuesHot aluminum dross |
| Appearance | Gray to black solid residue material, often in powder or granular form. Byproduct from aluminum remelting operations containing metallic aluminum, aluminum oxide, salt flux residues, and other impurities. |
| Flash Point | Not applicable (water-reactive solid) |
| Boiling Point | Not applicable (solid mixture) |
| Vapor Density | Not applicable (solid) |
| Water Reactivity | Dangerous when wet - reacts with water to produce flammable hydrogen gas and heat. May ignite spontaneously on contact with water or moist air. |
Fireground Response Guidance — UN 3170
Extinguishing Media
PPE Requirements
Use positive-pressure SCBA for vapor, dust, smoke, fire or confined-space exposure. Wear chemical-resistant gloves, eye/face protection and protective clothing.
Isolation & Evacuation
First Actions for a UN 3170 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, gas, dust, mist, smoke or fumes and avoid skin or eye contact.
- Keep water or moisture away unless specialist guidance confirms compatibility.
- Do not touch damaged containers, cylinders, articles or spilled material without proper training and PPE.
- Prevent contaminated runoff, debris and decontamination waste from spreading.
- Ventilate confined spaces only after monitoring and only if properly trained and equipped.
- Use ERG Guide 138, SDS, shipping papers, markings and monitoring to set isolation, evacuation and entry decisions.
📋 Copy & Share Field Card
UN 3170 — Aluminum remelting by-productsUse 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.