1. a) Incompatible wastes or incompatible wastes and materials (see appendix V of 40 CFR 265 (Examples of Potentially Incompatible Waste), incorporated by reference in 35 Ill. Adm. Code 720.111(b), for examples) must not be placed in the same container, unless Section 725.117(b) is complied with.
2. b) Hazardous waste must not be placed in an unwashed container that previously held an incompatible waste or material (see appendix V of 40 CFR 265, for examples), unless Section 725.117(b) is complied with.

3. c) A storage container holding a hazardous waste that is incompatible with any waste or other materials stored nearby in other containers, piles, open tanks, or surface impoundments must be separated from the other materials or protected from them by means of a dike, berm, wall, or other device.

   BOARD NOTE: The purpose of this is to prevent fires, explosions, gaseous emissions, leaching, or other discharge or hazardous waste or hazardous waste constituents that could result from the mixing of incompatible wastes or materials if containers break or leak.

(Source: Amended at 30 Ill. Reg. 3460, effective February 23, 2006)