; 38 U.S.C. 527 note). (II) The term open burn pit has the meaning given that term in section 201(c) of the Dignified Burial and Other Veterans’ Benefits Improvement Act of 2012 ( Public Law 112–260 ; 38 U.S.C. 527 note). (III) The term toxic substance means a toxicant or a toxin. (IV) The term toxicant means any substance that can injure or kill humans, animals, or plants and that is produced by humans or is a by-product of human activities. (V) The term toxin means any substance that can injure or kill humans, animals, or plants and that is produced naturally.