☣️ HAZMAT HUB  ·  UN LOOKUP  ·  CLASS 1–9

Hazmat Hub for Firefighters

Search UN/NA numbers, explore DOT Classes 1–9, and review NFPA 704 basics. Built for training & preplanning — always follow SOP/SOG + current ERG.

🚒☣️
DOT CLASSES 1–9 + UN LOOKUP
⚠️ Training/quick-reference only. For real incidents, consult the current ERG and follow your agency's SOP/SOG.
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UN Numbers by DOT Class

Quick-reference links. Always consult current ERG + SOP/SOG for incident actions.

Can't find a UN? Use the full UN Lookup →

DOT Hazmat Classes 1–9

Tap a class for firefighter-level overview, hazards, first actions, and UN examples.

Class Guides

🚒 First 5 Minutes Checklist

Initial approach
  • Stage uphill / upwind when possible
  • Establish isolation perimeter; deny entry
  • ID placards & UN markings from safe distance
  • Request Hazmat team early — don't wait
Command & safety
  • Accountability & hot/warm/cold zones
  • Protect exposures without unnecessary entry
  • Consult current ERG for isolation distances
  • Follow SOP/SOG — no freelancing

🟦 NFPA 704 Diamond — Quick Reference

0–4 scale meaning
  • 0 = Minimal hazard
  • 1 = Slight hazard
  • 2 = Moderate hazard
  • 3 = Serious hazard
  • 4 = Severe / extreme hazard
Quadrant colors
  • Blue = Health hazard
  • Red = Flammability
  • Yellow = Reactivity / instability
  • White = Special hazards (OX, W̶ etc.)
  • Fixed facilities only — does not replace SDS/ERG

FAQ

Find the UN/NA number on the placard, orange panel, shipping papers, or container markings, then consult the current ERG and your SOP/SOG. This hub helps you identify the class and common hazards quickly during training or preplanning.

No. This is a training and quick-reference aid only. Always follow your department's SOP/SOG and the current Emergency Response Guidebook (ERG) for incident-specific protective actions.

The 9 DOT hazmat transport classes are: Class 1 Explosives, Class 2 Gases, Class 3 Flammable Liquids, Class 4 Flammable Solids, Class 5 Oxidizers and Organic Peroxides, Class 6 Toxic and Infectious Substances, Class 7 Radioactive Materials, Class 8 Corrosives, and Class 9 Miscellaneous Dangerous Goods.

NFPA 704 uses a diamond-shaped sign with four colored quadrants: blue (health hazard), red (flammability), yellow (reactivity), and white (special hazards). Numbers 0 to 4 indicate severity, where 0 is minimal and 4 is severe. It is commonly found on fixed facilities and provides fast hazard awareness during size-up.
Sources: DOT/PHMSA class definitions, NFPA 704 standard overview, ERG usage principles. Always consult the current ERG for field operations.
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