☣️ UN 3537 • CLASS 2
Articles containing flammable gas, n.o.s.
Placard: Flammable Gas. Training/quick-reference only — use current ERG + SOP/SOG for incident-specific actions.
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⚠️ 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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Quick details
UN 3537
Class: 2
Placard type: Flammable Gas
ERG: Guide 115 (check current ERG)
Isolation: ERG 115: Initial isolation 100m all directions; protect from heat/ignition sources; evacuate area if container/article rupture risk; increase distances for large quantities or fire involvement
Chemical & Response Details
| Also known as | Articles with flammable gasGas-filled articles NOSPressurized flammable gas articlesGas aerosol containers |
| Appearance | Manufactured articles or devices containing compressed or liquefied flammable gases. Physical appearance varies based on the article type (cylinders, aerosols, cartridges, etc.). Gas inside is typically colorless or has characteristic odor depending on the specific gas. |
| Flash Point | Not applicable (compressed/liquefied gas in article) |
| Boiling Point | Varies depending on specific gas contained in article |
| Vapor Density | Varies depending on specific gas; typically heavier than air for liquefied gases |
| Water Reactivity | No significant reaction with water; primary hazard is release of flammable gas |
| Extinguishing | Dry chemical, CO2, water spray to cool containers; foam not typically applicable to gas fires |
| PPE | ⚠️ Level B minimum for gas release; SCBA mandatory; fire proximity suits if fire exposure; protect against pressure release hazards |
| Isolation | ERG 115: Initial isolation 100m all directions; protect from heat/ignition sources; evacuate area if container/article rupture risk; increase distances for large quantities or fire involvement |
Chemical details are general reference only. Always verify with current SDS, ERG, and SOP/SOG.
Common hazards (high level)
- EXTREMELY FLAMMABLE.
- Will be easily ignited by heat, sparks or flames.
- Will form explosive mixtures with air.
- Vapors from liquefied gas are initially heavier than air and spread along ground.
- Vapors may travel to source of ignition and flash back.
- Cylinders exposed to fire may vent and release flammable gas through pressure relief devices.
- Containers may explode when heated.
- Ruptured cylinders may rocket.
First actions (field-minded)
- CALL 911. Then call emergency response telephone number on shipping paper. If shipping paper
- Keep unauthorized personnel away.
- Stay upwind, uphill and/or upstream.
- Many gases are heavier than air and will spread along the ground and collect in low or confined areas
- Isolate spill or leak area for at least 100 meters (330 feet) in all directions.
- Consider initial downwind evacuation for at least 800 meters (1/2 mile).
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UN 3537 — Articles containing flammable gas, n.o.s HAZMAT RADIO NOTE — UN 3537
Product: Articles containing flammable gas, n.o.s.
Class 2 / Flammable Gas / ERG 115
PPE: Level B minimum for gas release; SCBA mandatory; fire proximity suits if fire exposure; protect against pressure release hazards
ISOLATION: ERG 115: Initial isolation 100m all directions; protect from heat/ignition sources; evacuate area if container/article rupture risk; increase distances for large quantities or fire involvement
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 3537 — Articles containing flammable gas, n.o.s.
Class: 2 | Placard: Flammable Gas | ERG Guide: 115
Appearance: Manufactured articles or devices containing compressed or liquefied flammable gases. Physical appearance varies based on the article type (cylinders, aerosols, cartridges, etc.). Gas inside is typically colorless or has characteristic odor depending on the specific gas.
Water Reactivity: No significant reaction with water; primary hazard is release of flammable gas
Extinguishing: Dry chemical, CO2, water spray to cool containers; foam not typically applicable to gas fires
PPE: Level B minimum for gas release; SCBA mandatory; fire proximity suits if fire exposure; protect against pressure release hazards
Isolation: ERG 115: Initial isolation 100m all directions; protect from heat/ignition sources; evacuate area if container/article rupture risk; increase distances for large quantities or fire involvement
— Key Hazards —
• EXTREMELY FLAMMABLE.
• Will be easily ignited by heat, sparks or flames.
• Will form explosive mixtures with air.
— 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.
• Many gases are heavier than air and will spread along the ground and collect in low or confined areas
SOURCE: allfirefighter.com/hazmat/un/3537 | Always use current ERG + SOP/SOGIC BRIEFING
Use for: Incident command briefing, staging area whiteboard, or pre-entry team brief. Full chemical + response details.
UN3537 Articles containing flammable gas, n.o.s. Cls2 ERG115 | allfirefighter.com/hazmat/un/3537SMS / 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/3537
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FAQ
EXTREMELY FLAMMABLE. Will be easily ignited by heat, sparks or flames. Will form explosive mixtures with air. Vapors from liquefied gas are initially heavier than air and spread along ground. Vapors may travel to source of ignition and flash back. Cylinders exposed to fire may vent and release flammable gas through pressure relief devices. Containers may explode when heated. Ruptured cylinders may rocket.
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 B minimum for gas release; SCBA mandatory; fire proximity suits if fire exposure; protect against pressure release hazards
No. This is a training/quick-reference aid only. Always consult the current ERG Guide 115 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.