Authorities are investigating after U.S. Customs and Border Protection officers seized 500-thousand counterfeit N95 masks last week in Chicago. The masks were confiscated from a shipment arriving from China September 10th. Officers sent 30 masks to a CDC testing office in West Virginia. The CDC concluded that ten-percent of the respirators tested had a filter efficiency rating below 95-percent. An appraisal estimated the domestic value of the masks to be more than three-million-dollars. The shipment was turned over to Homeland Security.