OC Strength
OC Concentration and Scoville Heat
Testing the Hotness of Pepper Sprays
Excerpts from Law Enforcement News
State of California
Memorandum
OC Concentration
-
Pepper
Spray Concentration
Confusion abounds concerning the efficacy of various pepper (oleoresin capsicum
"OC") sprays because of the U.S. Consumer Product Safety Commission's labeling
system. Often a consumer of civilian OC defense spray will see "5%" or
"10%" pepper spray claims on a canister. Unfortunately, these percentages do not
correlate with efficacy because they only measure the percentage of OC relative to the
other ingredients in the canister. These other ingredients include the carrier for the OC,
a propellant, and often marking dyes or other chemicals. An over-the-counter "10%" spray contains 10% Oleoresin Capsicum relative to
the rest of the ingredients. What the OC concentration does not measure is the
concentration of the active ingredients (Capsaicin) in the OC formulation. OC concentration therefore, only represents the amount of OC (oily resin) in a canister
and not its strength. The heat or strength of OC is measured by the quantity of an active
ingredient called Capsaicin*. Therefore, the higher the Capsaicin amount, the
hotter the OC. * Capsaicin is the ingredient within the OC that causes inflammation of
mucous membranes. The reason some peppers are hotter than others is due to the amount of
capsaicin. Capsaicin percentage changes depending on the pepper species, geographical
origin and climatic growth conditions as well as upon oleoresin extraction and formulation
processes. For example an OC spray with 5.5% concentration can be 5 times hotter than one
with 10% OC concentration.
| BrandnameOC Concentration |
Capsaicin within OC |
| First Defense10% |
0.18%A |
| CAP-STUN5.5% |
0.92%B |
First Defense is a trademark of Defense Technology Corporation of
America
A As disclosed to California Department of Justice and printed
on the canister. Tested via HPLC method.
B As disclosed to California Dept. of Justice and independent
laboratory test results. Tested via HPLC method.
SHU Scoville Heat Units
Laboratory Testing for Heat of Capsicum Peppers
A misconception exists that the heat of a pepper spray is best demonstrated through
Scoville Heat Units (SHU). SHU testing is none other than "tongue" tasting of
the OC by a panel of 5 individuals. SHU therefore depends on the subjective taste
experience of the panel. The SHU test is not accurate since it depends on the individual
taste sensitivity which changes from person to person and does not measure the actual
chemical percentage within the product. SHU test is an appropriate test for the food spice
community, however it cannot serve as the standard for OC weaponry, where an officer
depends on the OC's consistent and reliable performance.Therefore, to scientifically measure the amount of Capsaicin within OC sprays, High
Pressure Liquid Chromatography (HPLC)* is used to obtain exact and accurate machine data.
HPLC provides an acceptable international guideline for testing the Capsaicin amount by
the scientific community.
* See the Official Analytical Methods of The American Spice Trade Association
(HPLC method 21.1).
Testing the Hotness of Pepper Sprays
1. Capsaicin is the actual ingredient within the OC that causes burning
sensation and inflammation of mucous membranes. The amount of Capsaicin in layman terms,
is the cause of the hotness of chili peppers.
To scientifically measure the amount of Capsaicin within OC sprays, HPLC method is used
to obtain exact and accurate data. (See the Official Analytical Methods of the American
Spice Trade Association (HPLC method 21.1). This test method provides an acceptable
international guidelines for testing the Capsaicin amount by the scientific community.
2. For example, United States Testing laboratory HPLC on CAPSTUN
product resulted in 0.92% Capsaicin for Z-305 model. With the HPLC method the users are
rest assured that exactly 0.92% of Capsaicin is contained in the canister regardless of
the formula or other ingredients.
3. Scoville Heat "SHU" Test method (See the American Spice
Trade Association Method 21.0.) dates back to 1930's and is replaced by the modern and machine
accurate HPLC method.
SHU testing is none other than "tongue" tasting of the spice by a
panel of 5 individuals. SHU therefore depends on the subjective taste experience
of the panel. The SHU test is not accurate since it depends on the
individual taste sensitivity which changes from person to person and does not measure the
actual chemical percentage within the product. SHU test is an appropriate test for the
food spice community, however it cannot serve the weapon technology, where an officer
depends on the OC's high performance.
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Excerpts from Law Enforcement News
Answering Questions, Posing New Ones on the Use of OC Spray
By Eugene V. Morabito
Vol. XXII, No. 445. May 15, 1996
A publication of John Jay College of Criminal Justice/CUNY"The study of which I was a co-author, reviewed over 2,000 use-of-force reports
from the Tallahassee, Florida Police Department filed between May 1, 1993, and December
31, 1995.""A second phase of the study examined OC effectiveness. Pepper spray worked in
72.7 percent of the incidents". "Effectiveness was significantly lower for those offenders receiving multiple
doses. The effectiveness rate of these suspects was 58.3 percent."
Note: "First-Defense" brand of pepper spray from Defense
Technology Corporation of America was involved in these case studies.
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