These PIH drums meet 49 CFR requirements for overpacking materials that are Poisonous by Inhalation (PIH). The UN certified drums are tested to Packing Group I, Hazard Zones A and B. Our open head Poisonous by Inhalation Drums are constructed of 16-gauge (1.5 mm) steel. The PIH drums have passed a 100 kPa (15 psi) hydrostatic pressure test.