Senators James Inhofe (R-OK), David Vitter (R-LA), Jeff Session (R-AL), Tom Coburn (R-OK), and Lindsey Graham (R-SC) sent a letter August 3 to Environmental Protection Agency Administrator Lisa Jackson asking her to reconsider the toxicological assessment of halogenated platinum salts and platinum compounds and revise it to a more realistic estimate – one that is more easily measured – before it is finalized. The senators contended that the agency should not use its Integrated Risk Information System to assess the platinum as fuel additives for diesel engines. The International Platinum Group Metals Association expressed similar concerns in a May 24 letter to Bob Sussman.