A harmless symbol of Christmas cheer was once deemed so risky that the FDA had to regulate it. Tinsel once contained lead, which, as scientists realized in the 1960s, made it dangerous to kids. That prompted a deal between the FDA and tinsel makers to alter manufacturing methods, the American Chemical Society reports in a video. The 1972 change was at first kept secret, Popular Science reports, for fear “that many people preferring the lead variety would stockpile it,” an official said at the time. Believe it or not, that wasn’t the first time tinsel had posed a threat: One...