Brian Matayoshi would likely be alive today if he carried a $40 canister of bear repellent spray on Wednesday.
According to bear pepper spray research data compiled by Dr. Thomas Smith, an Associate Professor of Plant and Wildlife Sciences at Brigham Young University, bear spray stopped aggressive bears in 92% of the cases studied. The research covered twenty years of incidents in Alaska.
Of the 175 people who used bear spray and were involved in these incidents only three were injured and none went to the hospital. Contrast this with nearly 300 bear attacks involving firearms, the firearms were only effective in 67% of the cases.
According to Smith "The reason guns are less effective than bear spray is the difficulty of making an accurate shot during a split second chase. Smith's data shows it take an average of four hits to stop a bear. Bear spray is easier to carry and easier to use accurately in an emergency than a gun."
This article and the research it is based on are very interesting. I would suggest reading the article. Smith thinks one of the reasons bear spray is effective, is it requires the person being charged to hold their position, thereby avoiding triggering the bear's instinct to chase. Another upside is that a bear that has been sprayed in the past remembers it. I've heard reports that bears encountering humans with spray regularly are being conditioned to depart to avoid being sprayed. Sometimes this merely requires raising an arm in gesture similar to spraying.
Bart Bratlien of my neighborhood sporting good store, Capital Sports in Helena, MT took a few minutes to demonstrate proper deployment of bear spray and to discuss his choice of a "plan b" firearm in the off chance the bear spray fails.
We used a training canister for this video. Bratlien noted that actual spray with the pepper is heavier and will spray a longer distance than what you saw. It is also red in color.
I would highly suggest visiting the Interagency Grizzly Bear Committee for the most comprehensive, research-based bear safety information. The documents are well written, easy to read and very sensible.
Also, check out this video created by Counter Assault, a leading manufacturer of bear spray.
My wife, who works with bears for MT Fish Wildlife and Parks told me that to empty an expired canister, you spray the remaining contents into a bucket of water and poor the water out somewhere out of the way. Don't just throw it in your trash bin. If it is punctured or heated to the point it explodes, it will mess people up.