Now that you know how to properly use bear spray, this article examines factors influencing bear spray performance.
In a 2020 publication in the Journal of Wildlife Management, scientists examined the effects of temperature, wind, canister age, and repeated use on bear spray performance. The main takeaway is that bear spray is an important and effective deterrence tool in all areas where bears occur, even if it is windy or cold.
Specifically, they tested bear spray in temperatures ranging from -23C to +25 C. In all cases they achieved a spray distance of four meters or more. Even when used in the highest winds, coming directly towards the nozzle, the spray still reached 2 meters (the average distance of spray deployment in real incidents). When looking at repeated use, or test firing of bear spray, they found that approximately 50% of canister head pressure is lost during the first 1 second of spray use or greater. Finally, when examining the effect of time, the canisters lost about 1 gram of propellant for every year of age, supporting manufacturers' 4-year expiration dates.
Based on the results of this paper, they recommend the following guidelines:
Do not test‐fire new cans intended for use in the field
Keep canisters warm when in the cold, tucking them inside a parka or sleeping bag
Retire canisters of bear spray when they are expired
The link to the full article can also be found here.
Reminder: Bear spray should be carried year-round and it still works in freezing cold temperatures and in windy conditions!
Photo Source: Smith, T.S., Wilder, J.M., York, G., Obbard, M.E. and Billings, B.W. (2020), An Investigation of Factors Influencing Bear Spray Performance. Journal of Wildlife Management. doi:10.1002/jwmg.21958