Center, Internet, Wildlife Damage Management
Human–Wildlife Interactions
A Device for Refilling Practice Bear Spray Canisters
Date of this Version
Fall 2014
Document Type
Article
Citation
Human–Wildlife Interactions (Fall 2014) 8(2): article 14
doi: 10.26077/8ev0-qm54
Abstract
Studies have shown bear spray to be effective for deterring aggressive and nuisance bears (Herrero and Higgins 1998, Smith et al. 2007). Consequently, bear safety books encourage people to carry it into bear country (Schneider 2004, Smith 2006, Gookin and Reed 2009). Those who carry bear spray are encouraged to practice the sequence of unholstering, removing the safety clip, and test-firing the canister before encountering a bear for the first time (Schneider 2004, Smith 2006, Gookin and Reed 2009). Using bear spray for practice, however, may result in undesirable side effects on the user, such as debilitating blowback (Smith et al. 2007), residues that are attractive to bears (Smith 1998), or injury to persons carrying partially filled canisters into bear country. To avoid these problems, several bear-spray vendors (e.g., Counter Assault®, UDAP®, and Frontiersman®) market practice bear-spray canisters that lack capsaicinoid compounds, the active ingredient that irritates sensory nerve endings, particularly in the eyes and respiratory tracts (Herrero and Higgins 1998). Such training canisters, also called inert spray, perform similarly to actual bear spray by using propellants that expel a rapidly expanding cloud of inert carrier at a distance of approximately 7 m. More important than simulating spray with inert ingredients, however, is the opportunity to practice the sequence of events that brings bear spray into action: unholstering, removing the safety clip, aiming, and pressing the trigger. Cans of inert spray range in cost from $15 to $25 each (2014 pricing) and provide approximately 7 1-second bursts of spray. Hence, organizations with large numbers of personnel working in bear country either spend thousands of dollars on inert spray or limit the practice needed to master spray deployment. Those who cannot afford these costs often forego practice (T. Smith personal observation). The purpose of this paper is to promote bear-spray training by providing a low-cost alternative to the purchase of inert spray cans. We hope this device will encourage more organizations to practice bear-spray deployment until their people master use of this deterrent (Figure 1).
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Given the high-pressure air used in refilling canisters, eye protection is recommended. Suspending the device (i.e., from an overhead beam or ceiling) frees one hand for operating valves and adding pressure, while the other holds the canister in place on the device. To refill a canister, close the fill valve and open the water intake valve (Figure 2). Add 1 cup of water to the water intake funnel; let the water trickle downward into the device, then close the water intake valve. With the air compressor set to 95 pounds per square inch (PSI), attach a clamp-on tire inflator (i.e., does not require you to hold it in place) to the Schrader air valve. If using the refilling device suspended, raise a canister up onto the filler nozzle until firmly seated, and wrap 1 hand around both the top of the canister and bottom of the device to hold it in place. If not suspending the device, set the canister on a stable surface (i.e., table top), and lower the refilling nozzle into the canister until fully seated. Open the fill valve and add pressurized air until no more air is heard entering the refilling device, then close the fill valve. This not only forces the water down into the canister but also pressurizes the system to 95 PSI. Separate the canister and device, then open the water intake valve to release air pressure trapped between the 2 valves on the device. Reattach the head to the can by pressing until it snaps into place. Some canisters require the head assembly to be tightly attached for the trigger to work properly, while others work with loose heads. Some experimentation with spray assembly tightnesses will help determine what works best.