Which NFPA standard serves as a guide for fire investigators in conducting fire investigations?

• A. NFPA 1033
• B. NFPA 921
• C. NFPA 1561
• D. NFPA 1620

Answer: (B)

NFPA 921, the Guide for Fire and Explosion Investigations, is the standard that provides the systematic, evidence-based approach investigators use to determine where a fire began, what caused it, and how it spread. It lays out how to safely examine the scene, collect and preserve evidence, analyze burn patterns and ignition sources, and develop and test hypotheses so findings are documented and defensible. This guide emphasizes a scientific method to investigations, focusing on documentation, scene control, and reproducibility of results.

Other NFPA standards in the options serve different roles: one sets the minimum qualifications for who can perform investigations, another focuses on firefighter safety during incidents, and another covers pre-incident planning.