Ive found the OSHA requirements. "A safety can is (29CFR1926.155(1) an approved, closed container, of not more than 5 gallons capacity, having a flash arresting screen, spring closing lid and spout cover and so designed that it will safely relieve internal pressure when subjected to fire exposure." Given this, are they saying that the sealed premix cans on the shelf at home depot have a spring closing lid, and a pressure relieving capability? also does anyone know if they have a built in screen as to arrest sparks? im thinking they will simply say the cans are not refillable.