When the charging bear is 20 to 30 feet away, aim and spray a short burst for 1 to 2 seconds. “The goal is to get short bursts, not to spray the entire can at once,” Lynch said. “It's not like a fire extinguisher where the whole thing empties. You can control the amount and it’s designed to be sprayed in short bursts.” It’s also important to know your bear spray and read the label, as some cans could take longer to empty.