This guide details the scientific methodology for investigating fires and explosions.

The NFPA 921 serves as the definitive resource for professionals involved in fire and explosion investigations, aiming to improve the accuracy of determining origin, cause, incident responsibility, and prevention. It outlines the scientific method applicable to these investigations, making it a crucial tool for both public and private sector professionals in their field work and training. The document's increasing relevance in U.S. federal and state courts underscores its importance in evaluating the reliability of fire investigations in legal proceedings, with compliance potentially bolstering an investigator's credibility.

The NFPA 921 is recognized as the premier source for fire and explosion investigations, essential for professionals seeking to render accurate opinions on origin and cause. Its detailed scientific methodology is widely adopted in both practical field work and training programs. The guide's growing significance in U.S. federal and state courts highlights its role in assessing the validity of fire investigations in civil and criminal trials, making adherence to its standards critical for expert testimony.