Relating to Legislative Rules regarding chemicals of emerging concern

HB 4949 establishes rules for West Virginia's regulation of "chemicals of emerging concern," including PFAS (like PFOS/PFOA), microplastics, nanomaterials, and other substances posing potential environmental or health risks. The bill prohibits state rules on these chemicals from being stricter than existing federal standards for the same topic. If no federal rule exists, state regulations must be based on "best available science" and the "weight of scientific evidence," requiring a direct link between chemical exposure and proven human harm (not just risk). This applies to areas like drinking water, air quality, hazardous waste, and contaminated site cleanup, affecting state agencies developing environmental regulations.