Pepper Spray

Pepper spray, also known as OC spray (from "Oleoresin Capsicum"), OC gas, and capsicum spray, is a lachrymatory agent (a chemical compound that irritates the eyes to cause tears, pain, and even temporary blindness) used in policing, riot control, crowd control, and personal self-defense, including defense against dogs and bears. Its inflammatory effects cause the eyes to close, taking away vision. This temporary blindness allows officers to more easily restrain subjects and permits persons using pepper spray for self-defense an opportunity to escape. Although considered a less-than-lethal agent, it has been deadly in rare cases, and concerns have been raised about a number of deaths where being pepper sprayed may have been a contributing factor.

The active ingredient in pepper spray is capsaicin, which is a chemical derived from the fruit of plants in the Capsicum genus, including chilis. Extraction of oleoresin capsicum from peppers requires capsicum to be finely ground, from which capsaicin is then extracted using an organic solvent such as ethanol. The solvent is then evaporated, and the remaining waxlike resin is the oleoresin capsicum. An emulsifier such as propylene glycol is used to suspend the OC in water, and pressurized to make it aerosol in pepper spray. The high performance liquid chromatography (HPLC) method is used to measure the amount of capsaicin and major capsaicinoids within pepper sprays.

Determining the strength of different manufactures of pepper sprays can be confusing. The best and possibly the only reliable method is using the CRC of the product. The federal government of the United States has determined that Bear Attack Deterrent Sprays must contain at least 1.0% Capsaicin and Related Capsaicinoids. CRC does not measure the amount of Oleoresin Capsicum (OC) within the formulation. Instead, CRC is the heat bearing and pain producing components of the OC. The federal government of the United States makes no mention of SHU (Scoville heat units)or OC in their requirements, only CRC. Some manufactures may show a very high percentage of OC (Oleoresin Capsicum) and though OC is the active ingredient within the formulation it does not indicate pepper spray strength. The OC percentage only measures the amount of peppers contained in the defense spray, not the strength, pungency or effectiveness of the product. Other companies may show a high SHU, but again this is deceiving. The SHU is measured at the base resin and not by what comes out of the aerosol. The rated high heat of the resin can is diluted down depending on how much of it is put in the can.

A synthetic analogue of capsaicin, desmethyldihydrocapsaicin, is used in another version of pepper spray known as PAVA spray that is used in the United Kingdom. Another synthetic counterpart of pepper spray, pelargonic acid morpholide, was developed and is widely used in Russia. Its effectiveness compared to natural pepper spray is unclear. Pepper spray typically comes in canisters, which are often small enough to be carried or concealed in a pocket or purse. Pepper spray can also be purchased concealed in items such as rings. There are also pepper spray projectiles available, which can be fired from a paintball gun. It has been used for years against demonstrators. Many such canisters also contain dyes, either visible or UV-reactive, to mark an attacker's skin and/or clothing to enhance identification by police.