KINSTON, N.C. (June 20)—The Jan. 29 blast at West Pharmaceutical Services Inc.´s Kinston plant was caused by an explosion of fine plastic powder used to make the company's rubber medical products, according to the U.S. Chemical Safety Board. CSB leaders and investigators told a Kinston community audience at a June 18 meeting the dust explosion—which killed six people and injured many others—occurred above an area where rubber strips were coated with moistened polyethylene powder. The powder is used as a nonstick coating for rubber sheeting, and when dry, is fine and capable of forming explosive mixtures in the air, the CSB said. By installing a suspended ceiling at the plant years earlier, West inadvertently created a space where dust could accumulate out of view and an explosion could occur and then spread, said Angela Blair, a CSB investigator. The investigation is not yet complete, but when it is the full CSB will meet in Kinston to issue final safety recommendations in the case. West announced May 16 it is buying a plant four miles away from the original and re-establishing normal production by sometime in 2004.