Hazardous substance
Hazardous substance for the purposes of this subchapter, means a material, including its mixtures and solutions, that (1) Is listed in the appendix A to 172.101 of this subchapter; (2) Is in a quantity, in one package, which equals or exceeds the reportable quantity (RQ) listed in the appendix A to 172.101 of this subchapter; and (3) When in a mixture or solution (i) For radionuclides, conforms to paragraph 7 of the appendix A to 172.101. (ii) For other than radionuclides, is in a concentration by weight which equals or exceeds the concentration corresponding to the RQ of the material, as shown in the following table:
Source
49 CFR § 171.8
Scoping language
for the purposes of this subchapter