“Solid” means a substance or mixture of substances that, whether whole or subdivided into particles, such as those comprising a powder, is not capable of visually detectable flow using the method in ASTM D-4359-90(2000)e1. The term does not include liquids or gels.

Source. #10527, eff 2-26-14; ss by #13969, eff 5-21-24 (formerly Env-A 4104.47)