CHARLESTON, W.Va. (AP) -- The manufacturer of a breathing device used by coal miners in emergencies says it has expanded the scope of an investigation beyond an earlier recall of an oxygen starter.
CSE Corp. of Monroeville, Pa., notified the U.S. Mine Safety and Health Administration this week that until the main cause can be found, the problem could involve other SR-100 units than serial numbers previously identified.
CSE suspended production of the most popular self-contained self-rescuer unit in U.S. coal mines in February and recalled the entire production lot of more than 4,000 units sold. The company believed then that the problem affected less than 1 percent of those units.
CSE President Scott Shearer didn't immediately return a telephone message Tuesday night.