; and (C) withstand peer review. (4) An association between the occurrence of an illness in humans or animals and exposure to toxic airborne chemicals and fumes caused by open burn pits shall be considered to be positive for purposes of this subsection if the credible evidence for the association is equal to or outweighs the credible evidence against the association. (5) Not later than 60 days after receiving a report from the Open Burn Pit Advisory Commission regarding an illness, the Secretary shall make a determination under this subsection regarding that illness. (c) Regulations (1) If the Secretary determines under subsection (b) that a presumption of service connection is warranted for an illness, the Secretary shall issue proposed regulations setting forth the determination not later than 60 days after making the determination. (2) (A) If the Secretary determines under subsection (b) that a presumption of service connection is not warranted for an illness described in subsection (a)(2), the Secretary shall publish in the Federal Register a notice of that determination not later than 60 days after making the determination. The notice shall include an explanation of the evidence and scientific basis for that determination. (B) If an illness already presumed to be service connected under this section is subject to a determination under subparagraph (A), the Secretary shall issue proposed regulations removing the presumption for the illness not later than 60 days after publication of the notice of a determination that the presumption is not warranted. The notice shall include an explanation of the evidence and scientific basis for that determination. (3) Not later than 90 days after the date on which the Secretary issues any proposed regulations under this subsection, the Secretary shall issue final regulations. Such regulations shall be effective on the date of issuance. (4) Whenever the presumption of service connection for an illness under this section is removed under this subsection— (A) a veteran who was