Document ooxvjvpvJ9Y9eB8bVr25Leo7

Raymond J. Kent, Ph D. Senior Scientist U.S. Environmental Protection Agency Washington, D C., 20460 Dear Sir or Madam, It is my privilege to write a general letter of recommendation for Dr. William Irwin, DABT. I have known and worked with Dr. Irwin since he joined the EPA in 2009. He has a bachelor's degree in chemistry and a Ph D. in biochemistry (as I do) and I have relied on him for many years for his depth of knowledge in matters of chemistry and biochemistry. In addition, his extensive scientific knowledge and expertise extend well beyond chemistry, especially in the area of pharmacology and toxicology, providing invaluable scientific support for the regulation of pesticides. Among Will's various assignments at EPA, he is lead toxicologist for a number of high profile and complex chemicals such as chlorpyrifos, dicamba and amitraz. Based on his background and prior experience in sodium channel research, Will provides critical technical input to the pyrethroid class of insecticides. At the EPA's Office of Pesticide Programs, he is member of a variety of key committees including a toxicology scientific advisory committee (ToxSAC), a risk assessment advisory committee (RARC) and a committee that defines pesticide residues of concern (ROCKS). Apart from Will's current work in the OPP, Will's prior work on designing and implementing in vitro methods for high throughput and high content screening is utilized in the Agency's ToxCast program. As a scientific professional in the field of toxicology, Will is board certified as a Diplomate of the American Board of Toxicology, has given multiple presentations to the Society of Toxicology while at the Agency and is an editor of a toxicology journal. Will is highly respected by his colleagues. At the EPA, he can always be counted on to go the extra mile to ensure a robust scientific basis for regulatory action. I am confident Will would be a great asset to your organization. Sincerely, Raymond J. Kent, Ph D. Telephone:! Ex. 6 Sierra Club v. EPA 18cv3472 NDCA Attachments Prod 1 ED 002061 00039345-00001