What color smoke is produced by Class C fire?

• A. Black
• B. White
• C. Blue/Gray
• D. Orange

Answer: (C)

Class C fires involve energized electrical equipment. The smoke produced in this situation is typically blue or gray because the insulation, plastics, varnishes, and coatings found in electrical gear break down and burn, releasing bluish-gray fumes. This blue/gray smoke is a common training cue to quickly identify an electrical fire and distinguish it from other types. While exact colors can vary with materials present, blue/gray is the standard indicator for Class C. Other fires tend to show different smoke colors—black for hydrocarbon fuels, white for quickly burning organic materials like paper or wood—so blue/gray is the best fit for Class C.