Prohibits fuel oil, grade number four in any building or facility in the state

This bill prohibits the use of grade 4 fuel oil (a specific type of heavy fuel oil classified under ASTM D396-15c) in all buildings and facilities across the state after July 1, 2030. It directly affects commercial, industrial, and residential properties that currently rely on this fuel for heating or energy. The key provision sets a clear deadline for the phaseout, while allowing municipalities to adopt stricter local regulations if desired. The bill does not require immediate replacement but mandates a transition to alternative fuels or systems by the 2030 deadline. This is a substantive environmental regulation focused on reducing emissions from a specific fuel source.