SEATTLE — Dozens of hospitals in Washington state have learned that N95 respirator masks believed to be purchased from 3M are knockoffs and were not manufactured by the company. After receiving notice from 3M about the possibility that some masks were counterfeit, the Washington State Hospital Association on Friday alerted the state’s hospitals and asked them to pull potentially affected masks from their supplies. WSHA asked the state’s 115 hospitals to sort through their mask supplies and several have sent masks to 3M for testing. This weekend, the company confirmed that some were counterfeit...