The Navy has issued a partial ban on vaping after a series of what it characterizes as "mishaps," NPR reports. According to the Hill, there were 15 incidents involving e-cigarettes between October 2015 and June 2016. Eight of those incidents happened aboard vessels or aircraft, and two involved e-cigarettes exploding while actually in the mouths of sailors. The Navy says "multiple" sailors have been injured by exploding e-cigarettes, including some who've suffered first-degree burns and facial disfigurement. In addition to sailors, the ban—which bars anyone from possessing or using e-cigs on Navy crafts—is meant "to protect the ships, submarines, aircraft, and equipment." The ban goes into effect May 14 and doesn't affect vaping while on shore. (More vaping stories.)