Workers at a 40-person agency that investigates industrial accidents will vote whether to join the American Federation of Government Employees next week after staff discord and closure threats.

A majority of U.S. Chemical Safety Board employees have signed union interest cards, and the American Federation of Government Employees and agency management agreed to hold an election beginning April 9, Peter Winch, a special assistant for AFGE District 14 in Washington told Bloomberg Environment April 5.

If a majority of eligible employees approve, the union would be the first at the safety board since it became operational in 1998...