Oleoresin capsicum (OC or "pepper
spray"; not to be confused with "Mace," a commercial brand of CN
in aersol form) is a riot control agent used primarily by law enforcement
agencies and was not an agent standardized by the US military (OC is an
abbreviation, not a chemical agent code). This agent was in US military
inventory for use by military police for incapacitating violent or threatening
subjects, but also has applications for special forces and stability and
support operations.
OC is a naturally occurring substance
found in the oily resin of cayenne and other varieties of peppers, but can and
is also be produced synthetically. As a result, the various grades of OC are
often described using the Scoville scale developed by Wilbur Scoville in 1912
for measuring the "heat" of peppers. Sprays intended for use on
humans are rated generally between 200,000 and 2,000,000 Scoville Heat Units
(SHUs), while the hottest peppers generally range from 350,000 to 1,500,000
SHUs. Sprays intended for protection against large animals, such as bears
(leading to the colloquial term "Bear Mace", though again not to be
confused with Mace), come in grades sometimes over 9,000,000 SHUs. Pure
capsaicin is rated at 15,000,000 to 16,000,000 SHUs.
Contact with OC particles in a sprayed
mist incapacitates subjects by inducing an almost immediate burning sensation
of the skin and burning, tearing, and swelling of the eyes. When inhaled, the
respiratory tract becomes inflamed causing the mucous membranes to swell. This
restricts breathing to short, shallow breaths.
Standard RCAs like CS or CR also cause
tearing and respiratory discomfort (irritant effects), but do not induce the
inflammation and swelling effects of OC. OC is most commonly dispersed via a
hand-held canister similar to M32/36 dispersers and when sprayed most people
cannot keep their eyes open unless they physically hold their eyelids apart due
to the swelling. Fear and disorientation often result from this temporary
blindness. Affected personnel may also lose strength and coordination due to the
shortness of breath.
