☣️ UN 1343 • CLASS 4
UN 1343 — Phosphorus trisulphide, free from yellow and white phosphorus
Placard: Flammable Solid. ERG Guide 139. 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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UN 1343 Quick Details
UN 1343
Product name: Phosphorus trisulphide, free from yellow and white phosphorus
DOT Class: 4
Placard type: Flammable Solid
ERG Guide: 139 (check current ERG)
Initial isolation: ERG 139: Initial isolation 100m in all directions. Protective action distance up to 800m downwind for large spills. Evacuate immediate area if fire develops.
Common Hazards of UN 1343
- Produce flammable and toxic gases on contact with water.
- May ignite on contact with water or moist air.
- Some react vigorously or explosively on contact with water.
- May be ignited by heat, sparks or flames.
- May re-ignite after fire is extinguished.
- Some are transported in highly flammable liquids.
- Containers may explode when heated.
- Runoff may create fire or explosion hazard.
Chemical Identity & Physical Properties
| Also known as | Phosphorus sesquisulfideTetraphosphorus trisulfidePhosphorus sulfideP4S3Trisulfurated phosphorus |
| CAS Number | 1314-85-8 |
| Appearance | Grayish-yellow to greenish-yellow crystalline solid with a characteristic odor similar to rotten eggs or garlic. Free from yellow and white phosphorus impurities. |
| Flash Point | Not applicable (ignites spontaneously when in contact with moisture or friction) |
| Boiling Point | 407-408C (765-766F) with decomposition |
| Vapor Density | Not applicable (solid material) |
| Water Reactivity | Reacts with water producing toxic and flammable hydrogen sulfide (H2S) and phosphoric acid. May ignite spontaneously on contact with moisture. |
Chemical details are general reference only. Always verify with current SDS, ERG, and SOP/SOG.
Fireground Response Guidance — UN 1343
Extinguishing Media
Dry chemical, dry sand, soda ash. DO NOT use water, foam, or CO2.
PPE Requirements
⚠️ Level B minimum with full-face SCBA required. Chemical-resistant suit for spill cleanup. Respiratory protection mandatory due to toxic H2S gas evolution.
Isolation & Evacuation
ERG 139: Initial isolation 100m in all directions. Protective action distance up to 800m downwind for large spills. Evacuate immediate area if fire develops.
Always confirm protective actions with the current edition of the Emergency Response Guidebook (ERG Guide 139).
First Actions for a UN 1343 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.
- 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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📋 Copy & Share Field Card
UN 1343 — Phosphorus trisulphide, free from yellowHAZMAT RADIO NOTE — UN 1343
Product: Phosphorus trisulphide, free from yellow and white phosphorus
Class 4 / Flammable Solid / ERG 139
PPE: Level B minimum with full-face SCBA required. Chemical-resistant suit for spill cleanup. Respiratory protection mandatory due to toxic H2S gas evolution.
ISOLATION: ERG 139: Initial isolation 100m in all directions. Protective action distance up to 800m downwind for large spills. Evacuate immediate area if fire develops.
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 1343 — Phosphorus trisulphide, free from yellow and white phosphorus
Class: 4 | Placard: Flammable Solid | ERG Guide: 139
Appearance: Grayish-yellow to greenish-yellow crystalline solid with a characteristic odor similar to rotten eggs or garlic. Free from yellow and white phosphorus impurities.
Water Reactivity: Reacts with water producing toxic and flammable hydrogen sulfide (H2S) and phosphoric acid. May ignite spontaneously on contact with moisture.
Extinguishing: Dry chemical, dry sand, soda ash. DO NOT use water, foam, or CO2.
PPE: Level B minimum with full-face SCBA required. Chemical-resistant suit for spill cleanup. Respiratory protection mandatory due to toxic H2S gas evolution.
Isolation: ERG 139: Initial isolation 100m in all directions. Protective action distance up to 800m downwind for large spills. Evacuate immediate area if fire develops.
— Key Hazards —
• Produce flammable and toxic gases on contact with water.
• May ignite on contact with water or moist air.
• Some react vigorously or explosively on contact with water.
— 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/1343 | Always use current ERG + SOP/SOGIC BRIEFING
Use for: Incident command briefing, staging area whiteboard, or pre-entry team brief. Full chemical + response details.
UN1343 Phosphorus trisulphide, free from yellow and white phosphorus Cls4 ERG139 | allfirefighter.com/hazmat/un/1343SMS / 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/1343
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Frequently Asked Questions about UN 1343
Produce flammable and toxic gases on contact with water. May ignite on contact with water or moist air. Some react vigorously or explosively on contact with water. May be ignited by heat, sparks or flames. May re-ignite after fire is extinguished. Some are transported in highly flammable liquids. Containers may explode when heated. Runoff may create fire or explosion hazard.
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 with full-face SCBA required. Chemical-resistant suit for spill cleanup. Respiratory protection mandatory due to toxic H2S gas evolution.
Water reactivity: Reacts with water producing toxic and flammable hydrogen sulfide (H2S) and phosphoric acid. May ignite spontaneously on contact with moisture.. Recommended extinguishing: Dry chemical, dry sand, soda ash. DO NOT use water, foam, or CO2..
ERG Guide 139 recommendation: ERG 139: Initial isolation 100m in all directions. Protective action distance up to 800m downwind for large spills. Evacuate immediate area if fire develops.
No. This is a training/quick-reference aid only. Always consult the current ERG Guide 139 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.