The U.S. Chemical Safety and Hazardous Investigation Board says a draft proposal by the American Petroleum Institute does not adequately address risks associated with construction trailers and other temporary structures in hazardous areas. Fifteen contractors near or in trailers were killed in 2005 at the site of an explosion at a Texas City refinery. The proposal does not give minimum safe distance for trailers or “explicit” steps to protect occupants, claims the board. The study is limited to areas covered by process management safety standards and excludes other areas that contain hazards.