☣️ UN 3277 • CLASS 6

Chloroformates, poisonous, corrosive, n.o.s.

Placard: Toxic. 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 3277
Class: 6
Placard type: Toxic
ERG: Guide 154 (check current ERG)
Isolation: ERG 154: Initially isolate 50m in all directions; if tank/rail car involved in fire, isolate 800m in all directions
Chemical & Response Details
Also known asChloroformate estersChlorocarbonic acid estersChloroformiate compoundsCarbonic chloride esters
AppearanceColorless to pale yellow liquids with pungent, acrid odor. Corrosive and toxic liquids that may fume in moist air.
Flash PointVaries by specific chloroformate; typically -7°C to 16°C (19°F to 61°F), highly flammable
Boiling PointVaries by specific chloroformate; typically 50°C to 130°C (122°F to 266°F)
Vapor DensityGreater than 1 (heavier than air); vapors will accumulate in low areas
Water ReactivityReacts with water to release toxic and corrosive HCl gas; hydrolyzes readily in moisture
ExtinguishingAlcohol-resistant foam, CO2, dry chemical; water may cause violent reaction and toxic gas release
PPE⚠️ Level A required for spill response; SCBA mandatory; butyl rubber or Viton gloves; full chemical-resistant suit
IsolationERG 154: Initially isolate 50m in all directions; if tank/rail car involved in fire, isolate 800m in all directions
Chemical details are general reference only. Always verify with current SDS, ERG, and SOP/SOG.
Common hazards (high level)
  • TOXIC and/or CORROSIVE; inhalation, ingestion or skin contact with material may cause severe injury
  • Contact with molten substance may cause severe burns to skin and eyes.
  • Avoid any skin contact.
  • Fire may produce irritating, corrosive and/or toxic gases.
  • Runoff from fire control or dilution water may be corrosive and/or toxic and cause environmental
  • Non-combustible, substance itself does not burn but may decompose upon heating to produce corrosive
  • Some are oxidizers and may ignite combustibles (wood, paper, oil, clothing, etc.).
  • Corrosives in contact with metals may evolve flammable hydrogen gas.
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.
  • Ventilate closed spaces before entering, but only if properly trained and equipped.
  • Isolate spill or leak area in all directions for at least 50 meters (150 feet) for liquids and at least 25 meters
  • 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 3277 — Chloroformates, poisonous, corrosive, n.
HAZMAT RADIO NOTE — UN 3277 Product: Chloroformates, poisonous, corrosive, n.o.s. Class 6 / Toxic / ERG 154 PPE: Level A required for spill response; SCBA mandatory; butyl rubber or Viton gloves; full chemical-resistant suit ISOLATION: ERG 154: Initially isolate 50m in all directions; if tank/rail car involved in fire, isolate 800m in all directions 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 3277 — Chloroformates, poisonous, corrosive, n.o.s. Class: 6 | Placard: Toxic | ERG Guide: 154 Appearance: Colorless to pale yellow liquids with pungent, acrid odor. Corrosive and toxic liquids that may fume in moist air. Water Reactivity: Reacts with water to release toxic and corrosive HCl gas; hydrolyzes readily in moisture Extinguishing: Alcohol-resistant foam, CO2, dry chemical; water may cause violent reaction and toxic gas release PPE: Level A required for spill response; SCBA mandatory; butyl rubber or Viton gloves; full chemical-resistant suit Isolation: ERG 154: Initially isolate 50m in all directions; if tank/rail car involved in fire, isolate 800m in all directions — Key Hazards — • TOXIC and/or CORROSIVE; inhalation, ingestion or skin contact with material may cause severe injury • Contact with molten substance may cause severe burns to skin and eyes. • Avoid any skin contact. — 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. • Ventilate closed spaces before entering, but only if properly trained and equipped. SOURCE: allfirefighter.com/hazmat/un/3277 | 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)
UN3277 Chloroformates, poisonous, corrosive, n.o.s. Cls6 ERG154 | allfirefighter.com/hazmat/un/3277SMS / 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/3277
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 and/or CORROSIVE; inhalation, ingestion or skin contact with material may cause severe injury Contact with molten substance may cause severe burns to skin and eyes. Avoid any skin contact. Fire may produce irritating, corrosive and/or toxic gases. Runoff from fire control or dilution water may be corrosive and/or toxic and cause environmental Non-combustible, substance itself does not burn but may decompose upon heating to produce corrosive Some are oxidizers and may ignite combustibles (wood, paper, oil, clothing, etc.). Corrosives in contact with metals may evolve flammable hydrogen gas.

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 for spill response; SCBA mandatory; butyl rubber or Viton gloves; full chemical-resistant suit

No. This is a training/quick-reference aid only. Always consult the current ERG Guide 154 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.