☣️ UN 3386 • CLASS 6
UN 3386 — Poisonous by inhalation liquid, water-reactive, n.o.s. (Inhalation Hazard Zone B)
Placard: Toxic. ERG Guide 139. Training/quick-reference only — use current ERG + SOP/SOG for incident-specific actions.
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⚠️ 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 3386 is Poisonous by inhalation liquid, water-reactive, n.o.s. (Inhalation Hazard Zone B), a not-otherwise-specified hazmat entry assigned to ERG Guide 139. The exact product name on shipping papers and the SDS determine the final hazards, but initial response should assume the listed DOT hazard until proven otherwise.
Hazard overview: Zone B inhalation toxicity is the controlling hazard; dangerous reaction with water. Treat unknown releases as immediately dangerous.
Response guidance: For UN 3386, isolate the release, keep personnel upwind, keep the material dry, and use only dry chemical, dry sand, soda ash or lime unless product data says otherwise. Do not use water or foam.
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UN 3386 Quick Details
UN 3386
Product name: Poisonous by inhalation liquid, water-reactive, n.o.s. (Inhalation Hazard Zone B)
DOT Class: 6
Placard type: Toxic
ERG Guide: 139 (check current ERG)
Initial isolation: ERG 139: Isolate spill area immediately for at least 100m in all directions; consider initial evacuation for 500m in all directions; if tank/rail car involved in fire, isolate 800m in all directions and consider evacuation for 800m
Common Hazards of UN 3386
- 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
Variable appearance depending on specific substance; typically a liquid at room temperature that reacts with water or moisture. May have various colors and odors depending on the actual chemical identity.
| Also known as | PIH liquid water-reactiveToxic inhalation hazard liquid water-reactiveZone B water-reactive toxic liquidN.O.S. water-reactive poison |
| Appearance | Variable appearance depending on specific substance; typically a liquid at room temperature that reacts with water or moisture. May have various colors and odors depending on the actual chemical identity. |
| Flash Point | Variable by substance; many are flammable or produce flammable gases on contact with water |
| Boiling Point | Variable by substance; refer to specific chemical SDS |
| Vapor Density | Variable by substance; typically heavier than air for toxic vapors produced |
| Water Reactivity | Reacts with water producing toxic and flammable gases; do not use water except as fine spray to control vapors at a distance |
Chemical details are general reference only. Always verify with current SDS, ERG, and SOP/SOG.
Fireground Response Guidance — UN 3386
Extinguishing Media
Dry chemical, dry sand, or specialized extinguishing agents; avoid water-based agents due to water reactivity
PPE Requirements
⚠️ Level A required for unknown substances; minimum Level B with SCBA and full face protection; chemical-resistant suit required; positive pressure SCBA mandatory in vapor areas
Level A vapor-protective PPE with positive-pressure SCBA is appropriate for unknown or active releases. Avoid all skin contact and downgrade only after monitoring and product identification.
Isolation & Evacuation
ERG 139: Isolate spill area immediately for at least 100m in all directions; consider initial evacuation for 500m in all directions; if tank/rail car involved in fire, isolate 800m in all directions and consider evacuation for 800m
Always confirm protective actions with the current edition of the Emergency Response Guidebook (ERG Guide 139).
First Actions for a UN 3386 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.
- 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 direction.
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📋 Copy & Share Field Card
UN 3386 — Poisonous by inhalation liquid, water-reHAZMAT RADIO NOTE — UN 3386
Product: Poisonous by inhalation liquid, water-reactive, n.o.s. (Inhalation Hazard Zone B)
Class 6 / Toxic / ERG 139
PPE: Level A required for unknown substances; minimum Level B with SCBA and full face protection; chemical-resistant suit required; positive pressure SCBA mandatory in vapor areas
ISOLATION: ERG 139: Isolate spill area immediately for at least 100m in all directions; consider initial evacuation for 500m in all directions; if tank/rail car involved in fire, isolate 800m in all directions and consider evacuation for 800m
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 3386 — Poisonous by inhalation liquid, water-reactive, n.o.s. (Inhalation Hazard Zone B)
Class: 6 | Placard: Toxic | ERG Guide: 139
Appearance: Variable appearance depending on specific substance; typically a liquid at room temperature that reacts with water or moisture. May have various colors and odors depending on the actual chemical identity.
Water Reactivity: Reacts with water producing toxic and flammable gases; do not use water except as fine spray to control vapors at a distance
Extinguishing: Dry chemical, dry sand, or specialized extinguishing agents; avoid water-based agents due to water reactivity
PPE: Level A required for unknown substances; minimum Level B with SCBA and full face protection; chemical-resistant suit required; positive pressure SCBA mandatory in vapor areas
Isolation: ERG 139: Isolate spill area immediately for at least 100m in all directions; consider initial evacuation for 500m in all directions; if tank/rail car involved in fire, isolate 800m in all directions and consider evacuation for 800m
— 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 the emergency response telephone number on the shipping paper, if available.
• 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/poisonous-by-inhalation-liquid-un-3386 | Always use current ERG + SOP/SOGIC BRIEFING
Use for: Incident command briefing, staging area whiteboard, or pre-entry team brief.
UN3386 Poisonous by inhalation liquid, water-reactive, n.o.s. (Inhalation Hazard Zone B) Cls6 ERG139 | allfirefighter.com/hazmat/un/poisonous-by-inhalation-liquid-un-3386SMS / 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/poisonous-by-inhalation-liquid-un-3386
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Frequently Asked Questions about UN 3386
UN 3386 is Poisonous by inhalation liquid, water-reactive, n.o.s. (Inhalation Hazard Zone B). It is assigned to ERG Guide 139 for initial emergency response.
The main hazard is poisonous vapor exposure by inhalation (Zone B). Skin contact and ingestion may also be dangerous depending on the exact chemical.
Use Level A vapor-protective chemical suit with positive-pressure SCBA for unknown or active releases. Downgrade only after monitoring and product identification.
No. Water can produce flammable and toxic gases. Keep the material dry and use dry agents such as dry chemical, dry sand, soda ash or lime.
Because n.o.s. PIH entries cover multiple chemicals. The exact name, concentration and SDS determine final PPE, isolation and control tactics.
Avoid direct contact, vapor inhalation, unprotected entry, low areas where vapors collect, and any incompatible extinguishing agent or runoff path.
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.