☣️ UN 2813 • CLASS 4
UN 2813 — Water-reactive solid, n.o.s.
Placard: Dangerous When Wet. ERG Guide 138. 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.
Water-reactive solid, n.o.s. is a broad dangerous-when-wet entry. The specific material may release flammable gas, heat, toxic products or corrosive residue when contacted by moisture.
Hazard overview: The common response rule is to keep the material dry. Because this is an n.o.s. entry, water reactivity may range from vigorous gas release to explosive reaction.
Response guidance: Isolate the area, keep water and foam away and use dry media only when compatible with the product. Confirm the exact identity before disturbing damaged containers.
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UN 2813 Quick Details
UN 2813
Product name: Water-reactive solid, n.o.s.
DOT Class: 4
Placard type: Dangerous When Wet
ERG Guide: 138 (check current ERG)
Initial isolation: ERG 138: Initial isolation 25m in all directions. Protective action distance: Spill 100m downwind daytime, 300m nighttime. Fire: 800m radius evacuation.
Common Hazards of UN 2813
- This n.o.s. entry covers water-reactive solids with variable and sometimes severe behavior.
- Contact with water or moisture can release flammable gases and heat.
- Some materials may ignite or explode when wetted.
- Reaction products may be toxic, corrosive or irritating.
- Fire may re-ignite after apparent extinguishment if unreacted material remains.
- Wet runoff can create secondary fire, explosion or contamination hazards.
- Exact material identity is essential before applying extinguishing media.
Chemical Identity & Physical Properties
Appearance varies: powders, granules, pellets or solid pieces may all fall under this entry. Color and odor are not reliable indicators of hazard.
| Also known as | Water-reactive solid not otherwise specifiedDangerous when wet solid n.o.s.Water-sensitive solidHydro-reactive solid |
| Appearance | Appearance varies widely as this is a generic classification. May be powder, granules, or solid pieces. Color and odor depend on specific substance. Reacts with water to produce flammable gases. |
| Flash Point | Not applicable (reacts with water to produce flammable gases) |
| Boiling Point | Not applicable (varies by specific substance) |
| Vapor Density | Not applicable (solid material) |
| Water Reactivity | Reacts with water or moisture to produce flammable gases. May ignite spontaneously. Some substances react violently or explosively. Keep dry at all times. |
Chemical details are general reference only. Always verify with current SDS, ERG, and SOP/SOG.
Fireground Response Guidance — UN 2813
Extinguishing Media
Dry chemical, dry sand, dry sodium chloride powder. DO NOT use water, foam, or any water-based extinguishing agents.
PPE Requirements
⚠️ Level B minimum with SCBA required. Chemical-resistant suit and gloves. Keep upwind and avoid all contact with material and its water reaction products.
Use SCBA, eye and face protection, dry-compatible gloves and chemical protective clothing. Keep tools and absorbents dry.
Isolation & Evacuation
ERG 138: Initial isolation 25m in all directions. Protective action distance: Spill 100m downwind daytime, 300m nighttime. Fire: 800m radius evacuation.
Always confirm protective actions with the current edition of the Emergency Response Guidebook (ERG Guide 138).
First Actions for a UN 2813 Incident
- Call 911 and the emergency response number shown on the shipping papers or container documents.
- Keep unauthorized personnel away and isolate the area before approaching.
- Stay upwind, uphill and upstream; keep all water sources away from the material.
- Avoid breathing reaction gases, dust or smoke and avoid all skin and eye contact.
- Do not touch damaged containers or spilled material without dry-compatible PPE and tools.
- Do not apply water or foam unless a qualified hazmat specialist directs it for a specific product.
- Use ERG guidance, SDS, shipping papers and monitoring to confirm isolation and evacuation distances.
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📋 Copy & Share Field Card
UN 2813 — Water-reactive solid, n.o.s.HAZMAT RADIO NOTE — UN 2813
Product: Water-reactive solid, n.o.s.
Class 4 / Dangerous When Wet / ERG 138
PPE: Level B minimum with SCBA required. Chemical-resistant suit and gloves. Keep upwind and avoid all contact with material and its water reaction products.
ISOLATION: ERG 138: Initial isolation 25m in all directions. Protective action distance: Spill 100m downwind daytime, 300m nighttime. Fire: 800m radius evacuation.
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 2813 — Water-reactive solid, n.o.s.
Class: 4 | Placard: Dangerous When Wet | ERG Guide: 138
Appearance: Appearance varies widely as this is a generic classification. May be powder, granules, or solid pieces. Color and odor depend on specific substance. Reacts with water to produce flammable gases.
Water Reactivity: Reacts with water or moisture to produce flammable gases. May ignite spontaneously. Some substances react violently or explosively. Keep dry at all times.
Extinguishing: Dry chemical, dry sand, dry sodium chloride powder. DO NOT use water, foam, or any water-based extinguishing agents.
PPE: Level B minimum with SCBA required. Chemical-resistant suit and gloves. Keep upwind and avoid all contact with material and its water reaction products.
Isolation: ERG 138: Initial isolation 25m in all directions. Protective action distance: Spill 100m downwind daytime, 300m nighttime. Fire: 800m radius evacuation.
— Key Hazards —
• This n.o.s. entry covers water-reactive solids with variable and sometimes severe behavior.
• Contact with water or moisture can release flammable gases and heat.
• Some materials may ignite or explode when wetted.
— First Actions —
• Call 911 and the emergency response number shown on the shipping papers or container documents.
• Keep unauthorized personnel away and isolate the area before approaching.
• Stay upwind, uphill and upstream; keep all water sources away from the material.
• Avoid breathing reaction gases, dust or smoke and avoid all skin and eye contact.
SOURCE: allfirefighter.com/hazmat/un/water-reactive-solid-n-un-2813 | Always use current ERG + SOP/SOGIC BRIEFING
Use for: Incident command briefing, staging area whiteboard, or pre-entry team brief.
UN2813 Water-reactive solid, n.o.s. Cls4 ERG138 | allfirefighter.com/hazmat/un/water-reactive-solid-n-un-2813SMS / 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/water-reactive-solid-n-un-2813
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Frequently Asked Questions about UN 2813
Water contact can release flammable gas and heat, and some products may ignite or explode.
No. Foam is water-based and may worsen the reaction.
Dry chemical, dry sand or other product-approved dry media are considered first.
This n.o.s. entry covers many substances with different gas products and reaction severity.
Keep material dry, separate it from water sources and prevent wet runoff.
Yes. Unreacted material can re-ignite when it later contacts moisture.
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.