The chemical spill released 3,000 gallons of nitric acid from a tank at the Austin Powder Red Diamond Plant in McArthur– which manufactures explosives used for mining and construction – around 8:30 a.m. Wednesday, a Vinton County spokesperson told WLWT. Spillage from the 5,000-gallon tank caused nearby roads to shutter and the Federal Administration Authority to enforce a temporary flight restriction.