Table 1: Combustibility Hazards of Flammable Vapors and Combustible Dusts
| COMBUSTIBILITY HAZARDS | FLAMMABLE VAPORS/GASES | COMBUSTIBLE DUSTS | COMMENTS |
|---|---|---|---|
| Fire | Pool/Jet Fires | Dust-Accumulation/Layer Ignition (lower than minimum cloud ignition temperature | "Arrhenius" time/temperature behavior for dusts |
| Flash Fire | Unconfined vapors above pools; Unconfined leakage of flammable liquids, vapors, and gases | Unconfined combustible dust clouds, usually visible | - |
| Explosion | Confined vapors above pools; Confined leakage of flammable liquids, vapors, and gases | Confined dust clouds; Accumulation on elevated surfaces; Secondary explosion | Secondary explosion is very unlikely for flammable liquids, vapors and gases |
| Open Equipment | Hazardous; Not Permitted | Hazardous |