☣️ UN 3538 • CLASS 2

Articles containing nonflammable, non-toxic gas, n.o.s.

Placard: Non-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 3538
Class: 2
Placard type: Non-Flammable Gas
ERG: Guide 120 (check current ERG)
Isolation: ERG 120: Initial isolation 100m in all directions; no evacuation unless fire or major leak from ruptured container
Chemical & Response Details
Also known asArticles 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)
AppearanceVarious 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 PointNot applicable (non-flammable gas)
Boiling PointVaries by contained gas (e.g., nitrogen -196C, argon -186C, carbon dioxide sublimes -78C)
Vapor DensityHeavier than air when released (liquefied gas vapors initially settle before dispersing)
Water ReactivityNo significant reaction with water
ExtinguishingFoam not required; dry chemical or CO2 for incidental fires involving packaging
PPE⚠️ Level D sufficient for intact articles; Level C with SCBA if leak/rupture suspected; thermal gloves for contact with cryogenic liquids
IsolationERG 120: Initial isolation 100m in all directions; no evacuation unless fire or major leak from ruptured container
Chemical details are general reference only. Always verify with current SDS, ERG, and SOP/SOG.
Common hazards (high level)
  • Vapors may cause dizziness or asphyxiation without warning, especially when in closed or confined areas.
  • Vapors from liquefied gas are initially heavier than air and spread along ground.
  • Contact with gas, liquefied gas or cryogenic liquids may cause burns, severe injury and/or frostbite.
  • Non-flammable gases.
  • 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
  • Ventilate closed spaces before entering, but only if properly trained and equipped.
  • Isolate spill or leak area for at least 100 meters (330 feet) in all directions.
  • Consider initial downwind evacuation for at least 100 meters (330 feet).
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UN 3538 — Articles containing nonflammable, non-to
HAZMAT RADIO NOTE — UN 3538 Product: Articles containing nonflammable, non-toxic gas, n.o.s. Class 2 / Non-Flammable Gas / ERG 120 PPE: Level D sufficient for intact articles; Level C with SCBA if leak/rupture suspected; thermal gloves for contact with cryogenic liquids ISOLATION: ERG 120: Initial isolation 100m in all directions; no evacuation unless fire or major leak from ruptured container ACTION: Stage upwind · Isolate · Deny entry · Request HazmatRADIO

Use for: Quick radio or face-to-face size-up. Short, structured, field-ready.

SMS WhatsApp
=== IC HAZMAT BRIEFING === UN 3538 — Articles containing nonflammable, non-toxic gas, n.o.s. Class: 2 | Placard: Non-Flammable Gas | ERG Guide: 120 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. Water Reactivity: No significant reaction with water Extinguishing: Foam not required; dry chemical or CO2 for incidental fires involving packaging PPE: Level D sufficient for intact articles; Level C with SCBA if leak/rupture suspected; thermal gloves for contact with cryogenic liquids Isolation: ERG 120: Initial isolation 100m in all directions; no evacuation unless fire or major leak from ruptured container — Key Hazards — • Vapors may cause dizziness or asphyxiation without warning, especially when in closed or confined areas. • Vapors from liquefied gas are initially heavier than air and spread along ground. • Contact with gas, liquefied gas or cryogenic liquids may cause burns, severe injury and/or frostbite. — 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/3538 | Always use current ERG + SOP/SOGIC BRIEFING

Use for: Incident command briefing, staging area whiteboard, or pre-entry team brief. Full chemical + response details.

SMS (short)
UN3538 Articles containing nonflammable, non-toxic gas, n.o.s. Cls2 ERG120 | allfirefighter.com/hazmat/un/3538SMS / 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/3538
Related UN numbers (same class)
Discovery block for training / quick reference. Always consult the current ERG + your SOP/SOG for operations.
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FAQ

Vapors may cause dizziness or asphyxiation without warning, especially when in closed or confined areas. Vapors from liquefied gas are initially heavier than air and spread along ground. Contact with gas, liquefied gas or cryogenic liquids may cause burns, severe injury and/or frostbite. Non-flammable gases. 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 D sufficient for intact articles; Level C with SCBA if leak/rupture suspected; thermal gloves for contact with cryogenic liquids

No. This is a training/quick-reference aid only. Always consult the current ERG Guide 120 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.