☣️ UN 2940 • CLASS 4

UN 2940 — Cyclooctadiene phosphines

Placard: Spontaneously Combustible. ERG Guide 135. Training/quick-reference only — use current ERG + SOP/SOG for incident-specific actions.

🚒☣️
⚠️ Verification required: Broad or variable material category; verify exact product, SDS and shipping papers.
⚠️ 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.

UN 2940 is Cyclooctadiene phosphines, a moisture-sensitive spontaneously combustible phosphine entry assigned to ERG Guide 135. Product/SDS verification is important.

Hazard overview: SPONTANEOUSLY COMBUSTIBLE moisture-sensitive phosphine solid; may ignite on contact with air or moisture. May react with water or moist air, releasing heat and toxic phosphine/phosphorus-containing vapors. May burn rapidly and re-ignite after apparent extinguishment.

Response guidance: For UN 2940, isolate the area, avoid dust/friction and use SCBA. Use only compatible dry media, watch for re-ignition or violent decomposition and follow SDS/ERG 135.

Firefighter training notes: Training for UN 2940 should emphasize dry-media tactics, moisture/friction control, re-ignition, remote operations, SCBA use and runoff/debris control. Use ERG 135, SDS and local SOP.

Regulatory context: Cyclooctadiene phosphines is regulated as a hazardous material for transport and emergency response. Storage, reporting, exposure, waste and incident-notification duties depend on quantity, formulation and jurisdiction; verify shipping papers, SDS and authority guidance.

Storage & handling: Cyclooctadiene phosphines should be stored dry in tightly closed compatible containers away from moisture, heat, ignition sources and incompatible materials. Keep compatible dry media available.

Advertisement

UN 2940 Quick Details

UN 2940
Product name: Cyclooctadiene phosphines
DOT Class: 4
Placard type: Spontaneously Combustible
ERG Guide: 135 (check current ERG)
Initial isolation: ERG 135: isolate 25m in all directions; if tank/railcar involved in fire, isolate 800m all directions and evacuate 800m

Common Hazards of UN 2940

  • SPONTANEOUSLY COMBUSTIBLE moisture-sensitive phosphine solid; may ignite on contact with air or moisture.
  • May react with water or moist air, releasing heat and toxic phosphine/phosphorus-containing vapors.
  • May burn rapidly and re-ignite after apparent extinguishment.
  • Water, foam or CO2 may worsen some reactions or spread burning material.
  • Fire may produce phosphorus oxides and toxic organic smoke.
  • Runoff may carry reactive or toxic contamination.
  • Exact complex/formulation should be verified from SDS.

Chemical Identity & Physical Properties

Yellow to orange crystalline or powdery solid with a mild phosphine odor. Solid at room temperature, often moisture-sensitive.

Also known asCyclooctadiene phosphinesCOD phosphine complexes1,5-Cyclooctadiene phosphine compounds
AppearanceYellow to orange crystalline or powdery solid with a mild phosphine odor. Solid at room temperature, often moisture-sensitive.
Flash PointNot applicable (pyrophoric solid)
Boiling PointNot applicable (decomposes before boiling)
Vapor DensityNot applicable (solid)
Water ReactivityReacts with moisture and water, may ignite spontaneously on contact with moist air
Chemical details are general reference only. Always verify with current SDS, ERG, and SOP/SOG.

Fireground Response Guidance — UN 2940

Extinguishing Media

Use dry powder, dry sand, Class D media or SDS-approved dry media. Do not use water, foam or CO2 unless specialist guidance confirms compatibility.

PPE Requirements

⚠️ Level B minimum; SCBA required; full protective clothing to prevent skin contact

Use positive-pressure SCBA for fire, dust or smoke. Wear flame/chemical protection and avoid dust, friction and incompatible media.

Isolation & Evacuation

ERG 135: isolate 25m in all directions; if tank/railcar involved in fire, isolate 800m all directions and evacuate 800m
Always confirm protective actions with the current edition of the Emergency Response Guidebook (ERG Guide 135).

First Actions for a UN 2940 Incident

  • Call 911 and the emergency response number on the shipping paper, if available.
  • Keep unauthorized personnel away and establish incident command.
  • Stay upwind, uphill and upstream.
  • Avoid breathing vapor, dust, gas, mist, smoke or fumes and avoid skin or eye contact.
  • Keep water or moisture contact controlled because reaction, toxic fuming or re-ignition hazards may be severe.
  • Do not touch damaged containers or spilled material without proper training and PPE.
  • Prevent contaminated liquid, dust, runoff and decontamination waste from spreading.
  • Ventilate confined spaces only after monitoring and only if properly trained and equipped.
  • Use ERG Guide 135, SDS, shipping papers and monitoring to set isolation, evacuation and entry decisions.
Advertisement

📋 Copy & Share Field Card

UN 2940 — Cyclooctadiene phosphines
HAZMAT RADIO NOTE — UN 2940 Product: Cyclooctadiene phosphines Class 4 / Spontaneously Combustible / ERG 135 PPE: Level B minimum; SCBA required; full protective clothing to prevent skin contact ISOLATION: ERG 135: isolate 25m in all directions; if tank/railcar involved in fire, isolate 800m all directions and evacuate 800m 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 2940 — Cyclooctadiene phosphines Class: 4 | Placard: Spontaneously Combustible | ERG Guide: 135 Appearance: Yellow to orange crystalline or powdery solid with a mild phosphine odor. Solid at room temperature, often moisture-sensitive. Water Reactivity: Reacts with moisture and water, may ignite spontaneously on contact with moist air Extinguishing: Use dry powder, dry sand, Class D media or SDS-approved dry media. Do not use water, foam or CO2 unless specialist guidance confirms compatibility. PPE: Level B minimum; SCBA required; full protective clothing to prevent skin contact Isolation: ERG 135: isolate 25m in all directions; if tank/railcar involved in fire, isolate 800m all directions and evacuate 800m — Key Hazards — • SPONTANEOUSLY COMBUSTIBLE moisture-sensitive phosphine solid; may ignite on contact with air or moisture. • May react with water or moist air, releasing heat and toxic phosphine/phosphorus-containing vapors. • May burn rapidly and re-ignite after apparent extinguishment. — First Actions — • Call 911 and the emergency response number on the shipping paper, if available. • Keep unauthorized personnel away and establish incident command. • Stay upwind, uphill and upstream. • Avoid breathing vapor, dust, gas, mist, smoke or fumes and avoid skin or eye contact. SOURCE: allfirefighter.com/hazmat/un/cyclooctadiene-phosphines-un-2940 | Always use current ERG + SOP/SOGIC BRIEFING

Use for: Incident command briefing, staging area whiteboard, or pre-entry team brief.

SMS (short)
UN2940 Cyclooctadiene phosphines Cls4 ERG135 | allfirefighter.com/hazmat/un/cyclooctadiene-phosphines-un-2940SMS / 160 CHAR

Use for: Quick text to command or incoming units. Fits in a single SMS.

⚠️ Quick-reference only. Always use current ERG + SOP/SOG for incident-specific actions. Page: https://allfirefighter.com/hazmat/un/cyclooctadiene-phosphines-un-2940

Related UN Numbers in Class 4

Discovery block for training / quick reference. Always consult the current ERG + your SOP/SOG for operations.
Advertisement

Frequently Asked Questions about UN 2940

UN 2940 is Cyclooctadiene phosphines, assigned to ERG Guide 135.

Yes. Cyclooctadiene phosphines can ignite or burn under heat, moisture, friction or contamination conditions.

SPONTANEOUSLY COMBUSTIBLE moisture-sensitive phosphine solid; may ignite on contact with air or moisture. May react with water or moist air, releasing heat and toxic phosphine/phosphorus-containing vapors. May burn rapidly and re-ignite after apparent extinguishment.

Use positive-pressure SCBA for fire, dust or smoke. Wear flame/chemical protection and avoid dust, friction and incompatible media.

Use dry powder, dry sand, Class D media or SDS-approved dry media. Do not use water, foam or CO2 unless specialist guidance confirms compatibility.

Reactive residues, heat, friction, air or moisture can trigger renewed burning or decomposition.
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.