UN 3538 — Articles containing nonflammable, non-toxic gas, n.o.s.
Placard: Non-Flammable Gas. ERG Guide 120. Training/quick-reference only — use current ERG + SOP/SOG for incident-specific actions.
UN 3538 is Articles containing nonflammable, non-toxic gas, n.o.s., a broad nonflammable gas article entry assigned to ERG Guide 120. Stored pressure and rupture are primary hazards.
Hazard overview: Articles containing nonflammable, non-toxic gas, n.o.s.; stored pressure and rupture are the main hazards. Damaged articles can release gas rapidly and cause frostbite, oxygen displacement or mechanical injury depending on gas and pressure. Articles exposed to fire may rupture, fragment or eject components.
Response guidance: For UN 3538, isolate damaged articles, avoid cutting/crushing/heating and identify exact gas/pressure. Use SCBA and cool exposures from protection under ERG 120.
Firefighter training notes: Training for UN 3538 should emphasize product/article verification, SCBA use, pressure-release hazards, decontamination, runoff containment and SDS/shipping paper review. Use ERG 120, SDS and local SOP.
Regulatory context: Articles containing nonflammable, non-toxic gas, n.o.s. is regulated as a hazardous material for transport and emergency response. Storage, reporting, exposure, waste and incident-notification duties depend on quantity, package type, gas identity and jurisdiction; verify shipping papers, SDS and authority guidance.
Storage & handling: Articles containing nonflammable, non-toxic gas, n.o.s. should be stored in intact approved packages away from heat, physical damage and unauthorized access, with segregation and ventilation based on exact gas identity.
UN 3538 Quick Details
Common Hazards of UN 3538
- Articles containing nonflammable, non-toxic gas, n.o.s.; stored pressure and rupture are the main hazards.
- Damaged articles can release gas rapidly and cause frostbite, oxygen displacement or mechanical injury depending on gas and pressure.
- Articles exposed to fire may rupture, fragment or eject components.
- Gas may collect in low or confined areas if heavier than air.
- Fire may produce smoke from article materials even if the gas is nonflammable.
- Exact gas, pressure, quantity and article design must be verified.
- Do not cut, crush, puncture or heat unknown gas-containing articles.
Chemical Identity & Physical Properties
Various manufactured articles (aerosols, cartridges, cylinders) containing non-flammable, non-toxic compressed or liquefied gases. Gas may be colorless and odorless depending on specific product.
| Also known as | Articles containing compressed gas n.o.s.Articles containing liquefied gas n.o.s.Non-flammable gas articles n.o.s.Aerosol dispensers (non-flammable)Gas cartridges (non-flammable) |
| Appearance | Various manufactured articles (aerosols, cartridges, cylinders) containing non-flammable, non-toxic compressed or liquefied gases. Gas may be colorless and odorless depending on specific product. |
| Flash Point | Not applicable (non-flammable gas) |
| Boiling Point | Varies by contained gas (e.g., nitrogen -196C, argon -186C, carbon dioxide sublimes -78C) |
| Vapor Density | Heavier than air when released (liquefied gas vapors initially settle before dispersing) |
| Water Reactivity | No significant reaction with water |
Fireground Response Guidance — UN 3538
Extinguishing Media
PPE Requirements
Use positive-pressure SCBA where vapor, gas, dust, smoke or fire is present. Wear eye/face, hand and body protection suitable for the article or fuel.
Isolation & Evacuation
First Actions for a UN 3538 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.
- Do not touch damaged containers, equipment, articles 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 120, SDS, shipping papers and monitoring to set isolation, evacuation and entry decisions.
📋 Copy & Share Field Card
UN 3538 — Articles containing nonflammable, non-toUse 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.