Single Judge Application; solvent; Veterans Benefits Administration documents undermine the Secretary’s current claim of ignorance as to what constitutes a solvent. See, e.g., VA ADJUDICATIONS PROCEDURES MANUAL (M21-1MR), pt. IV, subpt. 2, ch. 1, § E(19)(g) (discussing solvent exposure in Gulf War veterans); VA Training Letter 10-01 (Feb. 4, 2010) (same); VA CLINICIANS’ GUIDE § 20.1 (same); VA Training Letter 07-04 (July 5, 2007) (solvent exposure in Navy divers); VA Training Letter 10-03 (Apr. 26, 2010) (solvent exposure from burn pits in Iraq, Afghanistan, and Djibouti and at the Naval Air Facility in Atsugi, Japan); VA Training Letter 11-03 (Nov. 21, 2011) (solvent exposure for veterans stationed at Camp Lejeune).;