Opinion ID: 513179
Heading Depth: 3
Heading Rank: 1

Heading: Text and Structure of the Statute

Text: 30 Both the wording and structure of TSCA reveal that Congress did not expect that EPA would have to document to a certainty the existence of an unreasonable risk before it could require testing. This is evident from the two-tier structure of the Act. In order for EPA to be empowered to regulate a chemical substance, the Agency must find that the substance presents or will present an unreasonable risk of injury to health or the environment. TSCA Sec. 6, 15 U.S.C. Sec. 2605(a). The testing provision at issue here, by contrast, empowers EPA to act at a lower threshold of certainty than that required for regulation. Specifically, testing is warranted if the substance may present an unreasonable risk of injury to health or the environment. TSCA Sec. 4, 15 U.S.C. Sec. 2603(a)(1)(A)(i) (emphasis added). Thus, the language of section 4 signals that EPA is to make a probabilistic determination of the presence of unreasonable risk.