☣️ UN 2921 • CLASS 8
Corrosive solid, flammable, n.o.s.
Placard: Corrosive. 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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Quick details
UN 2921
Class: 8
Placard type: Corrosive
ERG: Guide 134 (check current ERG)
Isolation: ERG 134: Initial isolation 50m in all directions; protective action distance 0.1km daytime/0.2km nighttime for small spills; 0.3km daytime/0.8km nighttime for large spills or fire
Chemical & Response Details
| Appearance | Variable appearance depending on specific substance; typically a solid material at room temperature that exhibits both corrosive and flammable properties. May range from crystalline to powdered form with varying colors and odors. |
| Flash Point | Variable; typically below 93°C (200°F) for flammable classification |
| Boiling Point | Variable depending on specific substance; decomposes or sublimates in many cases |
| Vapor Density | Variable; many corrosive solids produce heavier-than-air vapors when heated |
| Water Reactivity | May react with water producing heat and corrosive solutions; some formulations may react violently with water |
| Extinguishing | Dry chemical, CO2, sand, or earth; avoid water streams due to corrosive runoff and potential reactivity |
| PPE | ⚠️ Level B minimum with SCBA required; chemical-resistant suit and gloves necessary for corrosive protection; face shield and splash protection mandatory |
| Isolation | ERG 134: Initial isolation 50m in all directions; protective action distance 0.1km daytime/0.2km nighttime for small spills; 0.3km daytime/0.8km nighttime for large spills or fire |
Chemical details are general reference only. Always verify with current SDS, ERG, and SOP/SOG.
Common hazards (high level)
- Flammable/combustible material.
- May be ignited by heat, sparks or flames.
- When heated, vapors may form explosive mixtures with air: indoors, outdoors and sewers explosion
- Corrosives in contact with metals may evolve flammable hydrogen gas.
- Containers may explode when heated.
- TOXIC and/or CORROSIVE; inhalation, ingestion or skin contact with material may cause severe
- Fire will produce irritating, corrosive and/or toxic gases.
- Runoff from fire control or dilution water may be corrosive and/or toxic and cause environmental
First actions (field-minded)
- CALL 911. Then call emergency response telephone number on shipping paper. If shipping paper
- Stay upwind, uphill and/or upstream.
- Keep unauthorized personnel away.
- Ventilate closed spaces before entering, but only if properly trained and equipped.
- Isolate spill or leak area for at least 25 meters (75 feet) in all directions.
- Consider initial downwind evacuation for at least 100 meters (330 feet).
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UN 2921 — Corrosive solid, flammable, n.o.s. HAZMAT RADIO NOTE — UN 2921
Product: Corrosive solid, flammable, n.o.s.
Class 8 / Corrosive / ERG 134
PPE: Level B minimum with SCBA required; chemical-resistant suit and gloves necessary for corrosive protection; face shield and splash protection mandatory
ISOLATION: ERG 134: Initial isolation 50m in all directions; protective action distance 0.1km daytime/0.2km nighttime for small spills; 0.3km daytime/0.8km nighttime for large spills or fire
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 2921 — Corrosive solid, flammable, n.o.s.
Class: 8 | Placard: Corrosive | ERG Guide: 134
Appearance: Variable appearance depending on specific substance; typically a solid material at room temperature that exhibits both corrosive and flammable properties. May range from crystalline to powdered form with varying colors and odors.
Water Reactivity: May react with water producing heat and corrosive solutions; some formulations may react violently with water
Extinguishing: Dry chemical, CO2, sand, or earth; avoid water streams due to corrosive runoff and potential reactivity
PPE: Level B minimum with SCBA required; chemical-resistant suit and gloves necessary for corrosive protection; face shield and splash protection mandatory
Isolation: ERG 134: Initial isolation 50m in all directions; protective action distance 0.1km daytime/0.2km nighttime for small spills; 0.3km daytime/0.8km nighttime for large spills or fire
— Key Hazards —
• Flammable/combustible material.
• May be ignited by heat, sparks or flames.
• When heated, vapors may form explosive mixtures with air: indoors, outdoors and sewers explosion
— First Actions —
• CALL 911. Then call emergency response telephone number on shipping paper. If shipping paper
• Stay upwind, uphill and/or upstream.
• Keep unauthorized personnel away.
• Ventilate closed spaces before entering, but only if properly trained and equipped.
SOURCE: allfirefighter.com/hazmat/un/2921 | Always use current ERG + SOP/SOGIC BRIEFING
Use for: Incident command briefing, staging area whiteboard, or pre-entry team brief. Full chemical + response details.
UN2921 Corrosive solid, flammable, n.o.s. Cls8 ERG134 | allfirefighter.com/hazmat/un/2921SMS / 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/2921
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FAQ
Flammable/combustible material. May be ignited by heat, sparks or flames. When heated, vapors may form explosive mixtures with air: indoors, outdoors and sewers explosion Corrosives in contact with metals may evolve flammable hydrogen gas. Containers may explode when heated. TOXIC and/or CORROSIVE; inhalation, ingestion or skin contact with material may cause severe Fire will produce irritating, corrosive and/or toxic gases. Runoff from fire control or dilution water may be corrosive and/or toxic and cause environmental
CALL 911. Then call emergency response telephone number on shipping paper. If shipping paper Stay upwind, uphill and/or upstream. Keep unauthorized personnel away.
Level B minimum with SCBA required; chemical-resistant suit and gloves necessary for corrosive protection; face shield and splash protection mandatory
No. This is a training/quick-reference aid only. Always consult the current ERG Guide 134 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.