Bear spray is highly effective as a deterrent against aggressive bears, with studies showing success rates generally above 90%. It works by creating a cloud of irritating spray that targets a bear's eyes, nose, and lungs, causing temporary discomfort that stops the bear's undesirable behavior and gives chances to retreat safely.
Specifically, a 2008 study found bear spray stopped undesirable bear behavior 92% of the time for brown bears, 90% for black bears, and 100% for polar bears, with 98% of users escaping uninjured during close encounters. Other research reports the spray deters aggressive bears over 90% of the time. Bear spray is also considered safer and easier to use in high-stress situations than firearms and does not cause permanent harm to bears.
While no deterrent is 100% effective, bear spray is generally regarded as the best non-lethal defense against bear attacks, making it a highly recommended safety tool in bear country.
