Detection of sulfur mustard (HD) is an important step for preventing exposure to agent workers. Minicams™ instrumentation is used to monitor agent in the field and in the laboratory. We used a Minicams to detect and locate both sulfur mustard (HD) and a simulant, dibutyl sulfide (DBS), in an approved safety hood. The HD and the DBS sources were each one ml volumes at 9.5 mg/ml in hexanes contained in 1.5 ml vials that were opened for three minutes. The safer and more volatile DBS served as a simulant for detection at the front of the hood where HD is prohibited for safety reasons. We placed the HD in hexanes behind the 20-cm line that regulates how far from the front of the hood an agent operator can work with agent. After opening the vial for three minutes, HD was first detected seven cm in front of the vial, four cm to the left, four cm to the right, and four cm above the vial. With the detector placed at the front of the hood, DBS was first detected 4 cm from the front of the hood. These Minicams detection points for HD and DBS demonstrate the locus of HD near a source and give an example of the containment of DBS provided in a properly functioning hood. The results of this study show that the Minicams can detect HD at 0.3 ng/L in a hood in the absence of interfering analytes and that the Department of the Army agent safety standards are more than adequate for safe handling of HD.