ABSTRACT
The regulations of the Clean Air Act of 1991 in the United States are recorded in the congressional Federal Register [40 CFR Ch. 1 (7-1-91 Edition)], Subpart T, Standards of Performance for the Phosphate Fertilizer Industry: Wet-Process Phosphoric Acid Plants. Some of the requirements are:
1. The regulations apply to any wet-process phosphoric acid plant built or modified after October 22, 1974 with a capacity of more than 15 tons of equivalent feed of PzOs per day.
