☣️ 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.

🚒☣️

⚠️ 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.

Phosphorus trisulphide is a highly reactive substance that can produce toxic and flammable gases when exposed to water. It is essential to handle this substance with extreme caution.

Hazard overview: Phosphorus trisulphide can produce flammable and toxic gases on contact with water, and may ignite on contact with water or moist air.

Response guidance: In case of emergency, isolate the area and protect personnel from toxic hydrogen sulfide gas. Use dry chemical, dry sand, or soda ash to extinguish fires.

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

Phosphorus trisulphide is a grayish-yellow to greenish-yellow crystalline solid with a characteristic odor similar to rotten eggs or garlic.

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.

Level B minimum with full-face SCBA required, chemical-resistant suit for spill cleanup, and respiratory protection mandatory.

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

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

📋 Copy & Share Field Card

UN 1343 — Phosphorus trisulphide, free from yellow

HAZMAT 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.

SMS WhatsApp

=== 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 — • 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 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.

SMS (short)

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.

Open in Messages WhatsApp

⚠️ Quick-reference only. Always use current ERG + SOP/SOG for incident-specific actions. Page: https://allfirefighter.com/hazmat/un/phosphorus-trisulphide-free-from-un-1343

Related UN Numbers in Class 4

Open Class Guide →Hazmat Hub →

UN 1183 UN 1242 UN 1295 UN 1309 UN 1310 UN 1312 UN 1313 UN 1314 UN 1318 UN 1320 UN 1321 UN 1322

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

Frequently Asked Questions about UN 1343

Yes, UN 1343 can ignite on contact with water or moist air.

Yes, UN 1343 produces toxic hydrogen sulfide gas on contact with water.

No, do not use water, foam, or CO2 to extinguish UN 1343 fires.

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.