Quality assurance testing of an explosive trace analysis laboratory

During 1989, the Forensic Explosives Laboratory (FEL) established a weekly quality assurance testing regime in its explosives trace analysis laboratory. The purpose of the regime is to prevent the accumulation of explosives traces within the laboratory at levels which could, if other precautions failed, result in the contamination of samples and controls. This paper describes the regime and summarizes the results from approximately eight years of tests. Lessons learned and improvements made over the period are also discussed.