sentence1: approaches for setting different requirements for sources that pose different levels of hazard (tiering); worst-case releases and other hazard assessment issues; accident information reporting; public participation; inherently safer approaches; and implementation and integration of section 112(r) with state programs, particularly state air permitting programs and true is true and true is true and true is true and true is true and true is true .
sentence2: Different requirements are required for different levels of hazard.