SCAQMD Rule 1147 regulates nitrogen oxides (NOx) emissions from miscellaneous combustion equipment. Recent rule amendments include additional equipment, such as microturbines, autoclaves, tunnel dryers, absorption chillers, and tunnel kilns.

• Rule 1147.1 regulates NOx from Aggregate Dryers and was adopted in August 2021.

• Rule 1147.2 regulates NOx from Metal Heating and Melting Furnaces.

Regional Clean Air Incentives Market (RECLAIM) facilities that have previously been exempt from the NOx requirements of these rules will become subject to them as the RECLAIM program winds down. These rules establish Best Available Retrofit Control Technology (BARCT) emission standards that RECLAIM facilities will have to meet in the future.