☣️ UN 1203 • CLASS 3

UN 1203 — Motor spirit

Placard: Flammable. ERG Guide 128. 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.

UN 1203 is Motor spirit, a Class 3 flammable petroleum liquid assigned to ERG Guide 128. It is commonly known as gasoline or petrol and is a high-priority response hazard because vapors can travel, flash back and explode in confined spaces.

Hazard overview: UN 1203 presents severe flammable vapor, flashback, sewer/basement explosion and tank-heating hazards. Gasoline vapors are heavier than air and can ignite far from the spill, while liquid can float on water and spread fire.

Response guidance: For a UN 1203 incident, responders should confirm the product using shipping papers, container markings, SDS and ERG Guide 128. Establish incident command, isolate the area, stay upwind and uphill, remove ignition sources when safe, keep vapors or runoff out of sewers and use compatible fire-control agents from a protected position.

Firefighter training notes: Training for UN 1203 should emphasize vapor-cloud travel, flashback, sewer/basement explosion risk, tank fire behavior, foam application and runoff control. Common errors include standing downwind, using water streams that spread fuel and underestimating vapors far from the spill.

Regulatory context: Motor spirit is regulated as a hazardous material for transportation and emergency response purposes. Transportation, workplace exposure, spill reporting, waste handling, storage and environmental requirements may vary by formulation, quantity and jurisdiction. Verify current requirements through shipping papers, SDS, facility documents and applicable DOT, OSHA, EPA, NFPA, state or local authority guidance.

Storage & handling: Motor spirit should be stored in tightly closed compatible containers in a cool, dry, well-ventilated flammable-liquid storage area. Keep away from heat, sparks, open flames, oxidizers and incompatible materials, with bonding/grounding, secondary containment and drain protection where required.

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UN 1203 Quick Details

UN 1203
Product name: Motor spirit
DOT Class: 3
Placard type: Flammable
ERG Guide: 128 (check current ERG)
Initial isolation: ERG 128: Initially isolate 50m in all directions; for large spill isolate 800m downwind; evacuate area if tank/railcar is involved in fire

Common Hazards of UN 1203

  • EXTREMELY FLAMMABLE liquid and vapor; will be easily ignited by heat, sparks or flames.
  • Vapors may form explosive mixtures with air and flash back to the source.
  • Vapors are heavier than air and may travel long distances to ignition sources or collect in sewers.
  • Vapor explosion hazard exists indoors, outdoors, in tanks, basements and sewers.
  • Liquid floats on water and may spread fire across surfaces or waterways.
  • Fire may produce irritating or toxic combustion products.
  • Containers, tanks or vehicles may rupture or explode when heated.

Chemical Identity & Physical Properties

Clear to pale yellow or light amber liquid with characteristic petroleum/gasoline odor. Highly volatile at room temperature.

Also known asGasolinePetrolMotor gasolineAutomotive fuelMogas
CAS Number86290-81-5
AppearanceClear to pale yellow or light amber liquid with characteristic petroleum/gasoline odor. Highly volatile at room temperature.
Flash Point-43°C (-45°F)
Boiling Point39°C to 204°C (102°F to 399°F) - mixture with variable boiling range
Vapor Density3-4 (heavier than air)
Water ReactivityInsoluble in water; floats and forms flammable layer on surface
Chemical details are general reference only. Always verify with current SDS, ERG, and SOP/SOG.

Fireground Response Guidance — UN 1203

Extinguishing Media

Use AFFF, alcohol-resistant foam where compatible, dry chemical or CO2 for fire control; water spray may cool tanks but may spread burning liquid if misapplied.

PPE Requirements

⚠️ Level B minimum with chemical-resistant suit; SCBA required in vapor area; avoid all ignition sources

Use positive-pressure SCBA for fire, heavy vapor or confined-space exposure. Chemical-resistant gloves, splash protection and protective clothing should be selected from SDS; avoid skin contact with petroleum liquids and contaminated runoff.

Isolation & Evacuation

ERG 128: Initially isolate 50m in all directions; for large spill isolate 800m downwind; evacuate area if tank/railcar is involved in fire
Always confirm protective actions with the current edition of the Emergency Response Guidebook (ERG Guide 128).

First Actions for a UN 1203 Incident

  • CALL 911. Then call the emergency response telephone number on the shipping paper, if available.
  • Keep unauthorized personnel away.
  • Stay upwind, uphill and/or upstream.
  • Eliminate ignition sources if it is safe to do so.
  • Do not touch or walk through spilled liquid unless properly trained and wearing appropriate protective equipment.
  • Keep vapors and runoff out of basements, sewers, drains and waterways.
  • Ventilate closed spaces before entering, but only if properly trained, equipped and authorized by incident command.
  • Isolate the spill or leak area for at least 50 meters (150 feet) in all directions.
  • For large spills, fire involvement or strong vapor movement, expand isolation and consider downwind evacuation based on monitoring and incident command.
  • Use ERG Guide 128, shipping papers, SDS and local SOP for protective actions and entry decisions.
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📋 Copy & Share Field Card

UN 1203 — Motor spirit
HAZMAT RADIO NOTE — UN 1203 Product: Motor spirit Class 3 / Flammable / ERG 128 PPE: Level B minimum with chemical-resistant suit; SCBA required in vapor area; avoid all ignition sources ISOLATION: ERG 128: Initially isolate 50m in all directions; for large spill isolate 800m downwind; evacuate area if tank/railcar is involved in fire 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 1203 — Motor spirit Class: 3 | Placard: Flammable | ERG Guide: 128 Appearance: Clear to pale yellow or light amber liquid with characteristic petroleum/gasoline odor. Highly volatile at room temperature. Water Reactivity: Insoluble in water; floats and forms flammable layer on surface Extinguishing: Use AFFF, alcohol-resistant foam where compatible, dry chemical or CO2 for fire control; water spray may cool tanks but may spread burning liquid if misapplied. PPE: Level B minimum with chemical-resistant suit; SCBA required in vapor area; avoid all ignition sources Isolation: ERG 128: Initially isolate 50m in all directions; for large spill isolate 800m downwind; evacuate area if tank/railcar is involved in fire — Key Hazards — • EXTREMELY FLAMMABLE liquid and vapor; will be easily ignited by heat, sparks or flames. • Vapors may form explosive mixtures with air and flash back to the source. • Vapors are heavier than air and may travel long distances to ignition sources or collect in sewers. — First Actions — • CALL 911. Then call the emergency response telephone number on the shipping paper, if available. • Keep unauthorized personnel away. • Stay upwind, uphill and/or upstream. • Eliminate ignition sources if it is safe to do so. SOURCE: allfirefighter.com/hazmat/un/motor-spirit-un-1203 | Always use current ERG + SOP/SOGIC BRIEFING

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

SMS (short)
UN1203 Motor spirit Cls3 ERG128 | allfirefighter.com/hazmat/un/motor-spirit-un-1203SMS / 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/motor-spirit-un-1203

Related UN Numbers in Class 3

Discovery block for training / quick reference. Always consult the current ERG + your SOP/SOG for operations.
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Frequently Asked Questions about UN 1203

UN 1203 is Motor spirit, a hazardous material assigned to ERG Guide 128.

Yes. It is extremely flammable and vapors can form explosive mixtures with air.

ERG Guide 128 applies to UN 1203 and should be used for initial isolation, protective actions and first response guidance.

UN 1203 presents severe flammable vapor, flashback, sewer/basement explosion and tank-heating hazards. Gasoline vapors are heavier than air and can ignite far from the spill, while liquid can float on water and spread fire.

Use positive-pressure SCBA for fire, heavy vapor or confined-space exposure. Chemical-resistant gloves, splash protection and protective clothing should be selected from SDS; avoid skin contact with petroleum liquids and contaminated runoff.

Responders should isolate the area, stay upwind and uphill, eliminate ignition sources when safe, prevent sewer entry, verify the product with SDS and follow ERG Guide 128, incident command and local SOP.
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.