Cheng Fong Chemical Co. Ltd is a Chinese active pharmaceutical ingredient (API) company that exports to the United States of America.[1] In September 2016, the US FDA issued a warning letter "following a five-day inspection in April 2016 that found the company failed to appropriately maintain its facilities and investigate reports of foreign particles in finished batches."[2] According to the FDA, Cheng Fong officials told investigators "that the rooms had never been cleaned.".[1]