Oleoresin capsicum (OC), or pepper spray, has gained wide acceptance as standard police equipment in law enforcement as a swift and effective method to subdue violent, dangerous suspects in the field. As a use-of-force method, however, OC spray has been alleged in the media to have been associated with a number of in-custody deaths. The goal of this study was to assess the safety of a commercially available OC spray in use by law enforcement agencies nationwide. The study was conducted as a randomized, cross-over, controlled trial on volunteer human subjects recruited from the local law enforcement training academy in San Diego County, California. Subjects participated in four different experimental trials in random order over two separate days in a pulmonary function testing laboratory: (a) placebo spray exposure followed by sitting position, (b) placebo spray exposure followed by restraint position, (c) OC spray exposure followed by sitting position, and (d) OC spray exposure followed by restraint position. Prior to participation, subjects completed a short questionnaire regarding their health status, history of lung disease and asthma, smoking history, medication use, and respiratory inhaler medication use. Prior to exposure, subjects also underwent a brief screening spirometry in the sitting position by means of a portable spirometry device to determine baseline pulmonary function. Subjects then placed their heads in a 5' x 3' x 3' exposure box that allowed their faces to be exposed to the spray. A one-second spray was delivered into the box from the end opposite the subject (approximately five feet away). Subjects remained in the box for five seconds after the spray was delivered. During this time, subjects underwent impedance monitoring to assess whether inhalation of the OC or placebo spray had occurred. After this exposure period, subjects were placed in either the sitting or prone maximal restraint position. Subjects remained in these positions for ten minutes. Repeat spirometric measurements were performed, oxygen saturation, blood pressure, end-tidal carbon dioxide levels, and pulse rate were recorded, and an arterial blood sample was drawn. A total of 34 subjects completed the study, comprising 128 separate analyzable study trials. Variables provided in all three parts of this collection include subject's age, gender, ethnicity, height, weight, body mass index, past medical history, tobacco use history, and history of medication use, as well as OC spray or placebo exposure and sitting or restraint position during the trial. Part 1 also includes tidal volume, respiratory rate, and heart rate at baseline and at 1, 5, 7, and 9 minutes, and systolic and diastolic blood pressure at baseline and at 3, 6, and 9 minutes. Additional variables in Part 2 include predicted forced vital capacity and predicted forced expiratory volume in 1 second, and the same measures at baseline, 1.5 minutes, and 10 minutes. Derived variables include percent predicted and mean percent predicted values involving the above variables. Part 3 also provides end-tidal carbon dioxide and oxygenation levels, oxygen saturation, oxygen consumption at baseline and at 1, 5, 7, and 9 minutes, blood pH, partial pressure of oxygen, and partial pressure of carbon dioxide at 8 minutes.