Missouri's air quality rules get new definitions, but nothing actually changes

The US environmental regulators have approved updates to how Missouri defines terms in its air quality rules. This update does not make the rules stricter or change air quality.

This document is a routine administrative update. It clarifies language but does not alter any requirements for polluters or change how air quality is measured or enforced. It is a bureaucratic housekeeping item, not a shift in environmental policy or impact.