☣️ UN 3505 • CLASS 2
UN 3505 — Chemical under pressure, flammable, corrosive, n.o.s.
Placard: Flammable Gas. ERG Guide 118. Training/quick-reference only — use current ERG + SOP/SOG for incident-specific actions.
🚒☣️
⚠️ 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.
Advertisement
UN 3505 Quick Details
UN 3505
Product name: Chemical under pressure, flammable, corrosive, n.o.s.
DOT Class: 2
Placard type: Flammable Gas
ERG Guide: 118 (check current ERG)
Initial isolation: ERG 118: Initial isolation 100m all directions; Protective action distance 300m downwind daytime, 800m nighttime for small spills; larger spills require greater distances
Common Hazards of UN 3505
- EXTREMELY FLAMMABLE.
- May be ignited by heat, sparks or flames.
- May 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.
- Some of these materials may react violently with water.
- Cylinders exposed to fire may vent and release flammable gas through pressure relief devices.
- Containers may explode when heated.
Chemical Identity & Physical Properties
| Also known as | Chemical under pressure flammable corrosive NOSCompressed chemical flammable corrosivePressurized flammable corrosive chemicalUN3505 |
| Appearance | Variable appearance depending on specific chemical; pressurized gas or liquefied gas mixture that is both flammable and corrosive. May be colorless to colored with various odors. |
| Flash Point | Not applicable (pressurized flammable gas) |
| Boiling Point | Variable depending on specific chemical composition |
| Vapor Density | Variable, typically heavier than air when released |
| Water Reactivity | May react depending on corrosive component; avoid water contact due to corrosive properties |
Chemical details are general reference only. Always verify with current SDS, ERG, and SOP/SOG.
Fireground Response Guidance — UN 3505
Extinguishing Media
Dry chemical, CO2; water spray for cooling only from distance; foam may be ineffective due to pressurized nature
PPE Requirements
⚠️ Level B minimum; SCBA required; chemical-resistant suit due to corrosive properties; full face protection mandatory
Isolation & Evacuation
ERG 118: Initial isolation 100m all directions; Protective action distance 300m downwind daytime, 800m nighttime for small spills; larger spills require greater distances
Always confirm protective actions with the current edition of the Emergency Response Guidebook (ERG Guide 118).
First Actions for a UN 3505 Incident
- 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.
- For highlighted materials: see Table 1 - Initial Isolation and Protective Action Distances.
- For non-highlighted materials: increase the immediate precautionary measure distance, in the downwind
Advertisement
📋 Copy & Share Field Card
UN 3505 — Chemical under pressure, flammable, corrHAZMAT RADIO NOTE — UN 3505
Product: Chemical under pressure, flammable, corrosive, n.o.s.
Class 2 / Flammable Gas / ERG 118
PPE: Level B minimum; SCBA required; chemical-resistant suit due to corrosive properties; full face protection mandatory
ISOLATION: ERG 118: Initial isolation 100m all directions; Protective action distance 300m downwind daytime, 800m nighttime for small spills; larger spills require greater distances
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 3505 — Chemical under pressure, flammable, corrosive, n.o.s.
Class: 2 | Placard: Flammable Gas | ERG Guide: 118
Appearance: Variable appearance depending on specific chemical; pressurized gas or liquefied gas mixture that is both flammable and corrosive. May be colorless to colored with various odors.
Water Reactivity: May react depending on corrosive component; avoid water contact due to corrosive properties
Extinguishing: Dry chemical, CO2; water spray for cooling only from distance; foam may be ineffective due to pressurized nature
PPE: Level B minimum; SCBA required; chemical-resistant suit due to corrosive properties; full face protection mandatory
Isolation: ERG 118: Initial isolation 100m all directions; Protective action distance 300m downwind daytime, 800m nighttime for small spills; larger spills require greater distances
— Key Hazards —
• EXTREMELY FLAMMABLE.
• May be ignited by heat, sparks or flames.
• May 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/3505 | Always use current ERG + SOP/SOGIC BRIEFING
Use for: Incident command briefing, staging area whiteboard, or pre-entry team brief. Full chemical + response details.
UN3505 Chemical under pressure, flammable, corrosive, n.o.s. Cls2 ERG118 | allfirefighter.com/hazmat/un/3505SMS / 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/3505
Advertisement
Frequently Asked Questions about UN 3505
EXTREMELY FLAMMABLE. May be ignited by heat, sparks or flames. May 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. Some of these materials may react violently with water. Cylinders exposed to fire may vent and release flammable gas through pressure relief devices. Containers may explode when heated.
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; SCBA required; chemical-resistant suit due to corrosive properties; full face protection mandatory
Water reactivity: May react depending on corrosive component; avoid water contact due to corrosive properties. Recommended extinguishing: Dry chemical, CO2; water spray for cooling only from distance; foam may be ineffective due to pressurized nature.
ERG Guide 118 recommendation: ERG 118: Initial isolation 100m all directions; Protective action distance 300m downwind daytime, 800m nighttime for small spills; larger spills require greater distances
No. This is a training/quick-reference aid only. Always consult the current ERG Guide 118 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.