A large percentage of Americans have red polyethylene gas cans in their garages. They are used to refuel chainsaws or lawnmowers or other equipment. Injuries resulting from exploding plastic gas cans (video) are surprisingly common. These injuries may include burnt skin, coma, and limb damage. The treatments required are extensive.
Tragically, about 40% of burn victims hurt due to gas cans are children. Fumes outside the gas can ignite as you pour or fill gas resulting in a flashback fire. Currently, gas cans have safety warnings that tell users to keep them away from flames and electric motors. But these warnings can be inadequate. Moreover, flame arrestors could make them safer.
Some manufacturers do install flame arrestors, but the law doesn't mandate their installation yet. They are small mesh screens that can keep gas cans from exploding. They are installed in the spout of the cans. Shockingly, it only costs 5 cents to include an arrestor in the design of the can and yet some manufacturers will not pay even that much to keep their consumers safe.