☣️ UN 3130 • CLASS 4

Water-reactive liquid, poisonous, n.o.s.

Placard: Dangerous When Wet. 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.
Advertisement
Quick details
UN 3130
Class: 4
Placard type: Dangerous When Wet
ERG: Guide 139 (check current ERG)
Isolation: ERG 139: isolate spill 50m all directions; if tank/rail car involved in fire isolate 800m and consider evacuation 800m; toxic gases evolved on contact with water
Chemical & Response Details
Also known asWater-reactive liquid, toxic, n.o.s.Water-reactive poisonous liquidDangerous when wet liquid, poisonousClass 4.3 toxic liquid
AppearanceVariable appearance depending on specific substance; n.o.s. designation covers multiple water-reactive liquids that produce toxic gases. Typically clear to colored liquids that react dangerously with moisture.
Flash PointVariable; many are pyrophoric and may ignite spontaneously on contact with water or moist air
Boiling PointVariable depending on specific chemical identity
Vapor DensityVariable; vapors typically heavier than air
Water ReactivityReacts violently with water producing flammable and toxic gases; DO NOT use water directly on material
ExtinguishingDry chemical, soda ash, lime, sand; DO NOT use water or foam
PPE⚠️ Level A recommended due to toxic gas generation; SCBA required; chemical-resistant suit; avoid all contact
IsolationERG 139: isolate spill 50m all directions; if tank/rail car involved in fire isolate 800m and consider evacuation 800m; toxic gases evolved on contact with water
Chemical details are general reference only. Always verify with current SDS, ERG, and SOP/SOG.
Common hazards (high level)
  • 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.
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
Advertisement
📋 Copy & Share
UN 3130 — Water-reactive liquid, poisonous, n.o.s.
HAZMAT RADIO NOTE — UN 3130 Product: Water-reactive liquid, poisonous, n.o.s. Class 4 / Dangerous When Wet / ERG 139 PPE: Level A recommended due to toxic gas generation; SCBA required; chemical-resistant suit; avoid all contact ISOLATION: ERG 139: isolate spill 50m all directions; if tank/rail car involved in fire isolate 800m and consider evacuation 800m; toxic gases evolved on contact with water 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 3130 — Water-reactive liquid, poisonous, n.o.s. Class: 4 | Placard: Dangerous When Wet | ERG Guide: 139 Appearance: Variable appearance depending on specific substance; n.o.s. designation covers multiple water-reactive liquids that produce toxic gases. Typically clear to colored liquids that react dangerously with moisture. Water Reactivity: Reacts violently with water producing flammable and toxic gases; DO NOT use water directly on material Extinguishing: Dry chemical, soda ash, lime, sand; DO NOT use water or foam PPE: Level A recommended due to toxic gas generation; SCBA required; chemical-resistant suit; avoid all contact Isolation: ERG 139: isolate spill 50m all directions; if tank/rail car involved in fire isolate 800m and consider evacuation 800m; toxic gases evolved on contact with water — 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/3130 | 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)
UN3130 Water-reactive liquid, poisonous, n.o.s. Cls4 ERG139 | allfirefighter.com/hazmat/un/3130SMS / 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/3130
Related UN numbers (same class)
Discovery block for training / quick reference. Always consult the current ERG + your SOP/SOG for operations.
Advertisement

FAQ

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 A recommended due to toxic gas generation; SCBA required; chemical-resistant suit; avoid all contact

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.