Where the standard is exceeded, consumer products and paint fall under regulation too — what reasonably available control technology means

1What falls on an area that exceeds the standard

The United States air regime sets nationwide standards and designates areas failing to meet them as nonattainment. Once designated, the state containing such an area must write a plan to reach the standard. What every such plan contains is reasonably available control technology.

Replacing every existing facility with the newest equipment is not realistic, so what is required is measures that are technically available and reasonable in cost. Where reasonableness lies is judged by industry and equipment type.

2Not only factories

The coverage is the striking part: not only factories with stacks, but consumer products and coatings. Ozone is not emitted directly; it forms when volatile organic compounds and nitrogen oxides react in sunlight. Those compounds evaporate from everyday products such as paint, cleaners and hair products. Because the sources are spread thin and wide, regulation extends beyond the factory gate.

3The state writes, the federal government approves

This too takes the form of a state writing rules, submitting them, and the agency approving them into the state implementation plan. Once approved, those state rules become enforceable as a matter of federal law as well. This site covers approvals of the same structure for other states, showing that the content differs while the mechanism is shared.

4Comments do arrive

The agency proposed approval on February 27, 2026 and received eleven sets of comments. Even a procedure as unglamorous as approving one state air plan draws comment, because for those who make the regulated products, which state regulates what bears directly on their business.