O.C. is in the form of a stream or spray and is employed widely by law enforcement as a less-than-lethal weapon to accomplish individual or crowd control. Questions have arisen as to the safety in using O.C., both to the target person and to the officer that employs it. This study examined 63 cases on the basis of details of the law enforcement confrontation and modified by examination of the pathologic and toxicologic information. All of these cases involved drugs, disease, and drugs and disease combined with confrontational situations. In 7 of the 63 cases the cause of death was due to "position asphyxia" because the position of the subject can not use the normal and accessory muscles to adequately move air in-and -out of the lungs. The subject is usually lying face down, hands cuffed behind, the subject lies on his abdomen, which forces the abdominal contents up against the diaphragm inhibiting its use. Thirty-two of the 63 cases were subdivided as such. The results show that there is no evidence that O.C. as used by law enforcement officers in confrontational situations is a total or contributing cause of death, except when pre-existing asthma (or disease-narrowed airways) is present. As a tool for the law enforcement officer, O.C. ranks at the low end of the escalation of force scale and is relatively innocuous. The effectivity of O.C. is approximately 1 in 5, but this study included violent subjects alone, so violent that death ensued from the confrontation. 8 references, 7 tables