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Evaluation of Oleoresin Capsicum (Pepper Spray) Canisters for Chemical Content and Reliability


Aerosol sprays containing oleoresin capsicum, an extract of hot peppers, have been widely used by law enforcement agencies to subdue non-cooperative individuals. Pepper sprays cause incapacitation through contact of the product with the skin, eyes, and respiratory system. The pain and irritation associated with pepper sprays arise from a family of compounds called capsaicinoids. While pepper sprays have generally proven to be effective in producing incapacitation, a failure rate of 10 % to 15 % has been observed. The current research effort investigates the physical and chemical properties of commercial pepper spray products, to survey variability in the devices and to identify potential sources of failure. As part of this effort, recommended product specifications are being developed.


A project to characterize the chemical composition and the physical characteristics of pepper spray products has been established in the Analytical Chemistry Division at the request of the NIST Office of Law Enforcement Standards (OLES) and with funding from the National Institute of Justice (NIJ). This effort was designed to establish product specifications to improve device reliability. The causes of failures have not been established, but may include low concentrations of the active ingredients, poor delivery, and variable subject response. To evaluate canister properties, physical and chemical testing was initiated for a broad sampling of commercially available pepper spray products. In the course of this work, specifications for acceptable performance have been established. A reliable set of quantitative chemical and physical measurements on a representative set of canisters is expected to provide a basis for determining the most likely causes of failures in the field and to provide a benchmark against which manufacturers can assess the performance of their products. These data and performance criteria may be used by manufacturers to develop more reliable products with lower failure rates. In turn, law enforcement personnel will have access to more reliable and effective devices.

Additional Technical Details:

Prior to implementation of testing, facilities and new instrumentation were developed. A test chamber was constructed for physical testing, and semi-automated devices were designed and fabricated for various physical and performance tests. These tests included canister spray capacity, pattern and range tests, durability tests (resistance to dropping, crushing, and extreme temperatures).  Environmental chambers have been constructed for storage of canisters under controlled conditions. Phase Doppler interferometry instrumentation was utilized to measure particle sizes near the point of impact within the test chamber. Over 1000 canister representing 11 commercial devices were utilized in product testing. In addition, tests have been performed on several canisters that have failed in actual field use. The data have been compiled, and specifications for acceptable performance have been drafted based on the variability observed.

Photograph of pepper spray canisters

Photograph of typical pepper spray canisters.

Major Accomplishments:

  • Testing protocols have been developed for physical and chemical properties, as well as device performance.
  • Physical and chemical properties of eleven commercial pepper spray products (≈1000 canisters) have been investigated.     
  • Draft specifications for device properties have been developed (including physical, compositional, and operational specifications).

Start Date:

October 1, 2003

End Date:


Lead Organizational Unit:





Richard G. Christensen (retired)
Karen W. Phinney (Division 645)
Cary Presser
Lane C. Sander
Edward White V (Division 645)

Associated Products:

Sander, L. C., Phinney, K. W., and Fatah, A. A. "Technical Standard for Oleoresin Capsicum Canisters," NISTIR ____, U.S. Department of Commerce, Gaithersburg, MD, (in preparation).

White V, E., Phinney, K. W., Porter, B., Sander, L. C., Christensen, R. G., Waddell, J., Fatah, A. A., and Thompson, R. Q. "Oleoresin Capsicum Canister Study," .(ed). NISTIR 7486, 1-79, U.S. Department of Commerce, Gaithersburg, MD, (2007).

Thompson, R. Q., Phinney, K. W., Sander, L. C., and Welch, M. J., "Reversed-phase liquid chromatography and argentation chromatography of the minor capsaicinoids," Anal. Bioanal. Chem., 381, 1432-1440 (2005).


Lane C. Sander
Phone 301-975-3117

Karen W. Phinney
Phone 301-975-4457

Alim A. Fatah
Phone 301-975-2753