☣️ UN 3355 • CLASS 2

Insecticide gas, poisonous, flammable, n.o.s. (Inhalation Hazard Zone A)

Placard: Toxic Gas. 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.
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Quick details
UN 3355
Class: 2
Placard type: Toxic Gas
ERG: Guide 119 (check current ERG)
Isolation: ERG 119: Isolate 800m (0.5 mi) all directions initially. Evacuate downwind 8+ km if large spill. Inhalation Hazard Zone A requires maximum protective actions
Chemical & Response Details
Also known asPoisonous insecticide gasToxic fumigant gasFlammable pest control gasHazardous insecticide vapor
AppearanceCompressed or liquefied gas, typically colorless to pale yellow. May have characteristic odor depending on specific insecticide formulation. Highly toxic by inhalation.
Flash PointNot applicable (flammable gas)
Boiling PointNot applicable (compressed gas, varies by formulation)
Vapor DensityHeavier than air (exact value depends on specific insecticide)
Water ReactivityNo significant reaction with water, though solubility varies by formulation
ExtinguishingDo not use water spray. Use dry chemical or CO2 if gas flow can be stopped safely
PPE⚠️ Level A required; SCBA with full encapsulating suit mandatory. Extreme inhalation hazard Zone A; skin absorption risk
IsolationERG 119: Isolate 800m (0.5 mi) all directions initially. Evacuate downwind 8+ km if large spill. Inhalation Hazard Zone A requires maximum protective actions
Chemical details are general reference only. Always verify with current SDS, ERG, and SOP/SOG.
Common hazards (high level)
  • TOXIC; may be fatal if inhaled or absorbed through skin. Some may cause severe skin burns and
  • Contact with gas or liquefied gas may cause burns, severe injury and/or frostbite.
  • Fire will produce irritating, corrosive and/or toxic gases.
  • Runoff from fire control or dilution water may cause environmental contamination.
  • Flammable; may be ignited by heat, sparks or flames.
  • May form explosive mixtures with air. Ethylene oxide (UN1040) may react explosively even in the
  • Those substances designated with a (P) may polymerize explosively when heated or involved in a fire.
  • Vapors from liquefied gas are initially heavier than air and spread along ground.
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.
  • 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
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UN 3355 — Insecticide gas, poisonous, flammable, n
HAZMAT RADIO NOTE — UN 3355 Product: Insecticide gas, poisonous, flammable, n.o.s. (Inhalation Hazard Zone A) Class 2 / Toxic Gas / ERG 119 PPE: Level A required; SCBA with full encapsulating suit mandatory. Extreme inhalation hazard Zone A; skin absorption risk ISOLATION: ERG 119: Isolate 800m (0.5 mi) all directions initially. Evacuate downwind 8+ km if large spill. Inhalation Hazard Zone A requires maximum protective actions 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 3355 — Insecticide gas, poisonous, flammable, n.o.s. (Inhalation Hazard Zone A) Class: 2 | Placard: Toxic Gas | ERG Guide: 119 Appearance: Compressed or liquefied gas, typically colorless to pale yellow. May have characteristic odor depending on specific insecticide formulation. Highly toxic by inhalation. Water Reactivity: No significant reaction with water, though solubility varies by formulation Extinguishing: Do not use water spray. Use dry chemical or CO2 if gas flow can be stopped safely PPE: Level A required; SCBA with full encapsulating suit mandatory. Extreme inhalation hazard Zone A; skin absorption risk Isolation: ERG 119: Isolate 800m (0.5 mi) all directions initially. Evacuate downwind 8+ km if large spill. Inhalation Hazard Zone A requires maximum protective actions — Key Hazards — • TOXIC; may be fatal if inhaled or absorbed through skin. Some may cause severe skin burns and • Contact with gas or liquefied gas may cause burns, severe injury and/or frostbite. • Fire will produce irritating, corrosive and/or toxic gases. — 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/3355 | 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)
UN3355 Insecticide gas, poisonous, flammable, n.o.s. (Inhalation Hazard Zone A) Cls2 ERG119 | allfirefighter.com/hazmat/un/3355SMS / 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/3355
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

TOXIC; may be fatal if inhaled or absorbed through skin. Some may cause severe skin burns and Contact with gas or liquefied gas may cause burns, severe injury and/or frostbite. Fire will produce irritating, corrosive and/or toxic gases. Runoff from fire control or dilution water may cause environmental contamination. Flammable; may be ignited by heat, sparks or flames. May form explosive mixtures with air. Ethylene oxide (UN1040) may react explosively even in the Those substances designated with a (P) may polymerize explosively when heated or involved in a fire. Vapors from liquefied gas are initially heavier than air and spread along ground.

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 A required; SCBA with full encapsulating suit mandatory. Extreme inhalation hazard Zone A; skin absorption risk

No. This is a training/quick-reference aid only. Always consult the current ERG Guide 119 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.