title: Perchlorate contamination from the detonation of insensitive high-explosive rounds.
abstract: The insensitive high-explosive PAX-21 was the first of its kind fielded in an artillery munition by the United States military. This formulation contains three main components: RDX, dinitroanisole, and ammonium perchlorate (AP). In March 2012, detonation tests were conducted on PAX-21 60mm mortar rounds to determine the energetic residues resulting from high-order and blow-in-place (BIP) detonations. Post-detonation residues were sampled and analyzed for the three main PAX-21 components. Concentrations of RDX and dinitroanisole in the samples were quite low, less than 0.1% of the munitions' original organic explosive filler mass, indicating high order or near high order detonations. However, disproportionately high concentrations of AP occurred in all residues. The residues averaged 15% of the original AP following high-order detonations and 38% of the original AP mass following the BIP operations. There was no correlation between AP residues and the RDX and dinitroanisole. Perchlorate readily leached from the detonation residues, with over 99% contained in the aqueous portion of the samples. Use of these rounds will result in billions of liters of water contaminated above drinking water perchlorate limits. As a result of this research, PAX-21 mortar rounds are currently restricted from use on US training ranges.
authors.affiliation: US Army Cold Regions Research and Engineering Laboratory, 72 Lyme Road, Hanover, NH, USA. Electronic address: Michael.Walsh@usace.army.mil.
authors.forename: Michael R
authors.initials: MR
authors.lastname: Walsh
authors.forename: Marianne E
authors.initials: ME
authors.lastname: Walsh
authors.forename: Charles A
authors.initials: CA
authors.lastname: Ramsey
authors.forename: Sylvie
authors.initials: S
authors.lastname: Brochu
authors.forename: Sonia
authors.initials: S
authors.lastname: Thiboutot
authors.forename: Guy
authors.initials: G
authors.lastname: Ampleman
mesh_terms: D053834:Explosive Agents; D010472:Perchlorates / Q000032:analysis*; D014481:United States
chemical_list: D053834:Explosive Agents; D010472:Perchlorates; C494474:perchlorate
keywords: 2,4-dinitroanisole; AP; BIP; CRREL; Cold Regions Research and Engineering Laboratory; DNAN; DRDC; Defence Research and Development Canada, Valcartier; Detonation residues; EPA; Environmental contamination; IHE; IM; Insensitive high explosives; MI/MIS; OTP; PAX-21; Perchlorate; QA; RDX; RPD; Range sustainability; UHPLC–MS; US Environmental Protection Agency; ammonium perchlorate; blow in place; cyclotrimethylene-trinitramine; insensitive high explosive; insensitive munition; multi-increment sampling; outside the plume (sampling decision unit); quality assurance; relative percent difference; ultra-high-pressure liquid chromatography–mass spectrometer