Precision Castparts Corporation, previously ranked at number one among the Toxic 100, has submitted data to US EPA revising its 2010 TRI reporting. Based on the pounds revisions, Precision Castparts ranks 10th on the Toxic 100. Furthermore, Precision Castparts undertook testing of the share of hexavalent chromium in its total chromium releases. With facility-specific data on the hexavalent chromium share replacing US EPA's estimates, Precision Castparts ranks 20th on the Toxic 100. Precision Castparts indicates that its cobalt and nickel releases are in forms (elemental and specific compounds) that are less toxic than those assumed by EPA's RSEI model. The next edition of the Toxic 100 will reflect the most current information.