40 CFR 63.620 - Applicability.
(a) Except as provided in paragraphs (c) and (d) of this section, you are subject to the requirements of this subpart if you own or operate a phosphate fertilizer production plant that is a major source as defined in § 63.2. You must comply with the emission limitations, work practice standards, and operating parameter requirements specified in this subpart at all times.
(1) Each phosphate fertilizer process line (e.g., diammonium and/or monoammonium phosphate process line).
(d) The provisions of this subpart do not apply to research and development facilities as defined in § 63.621.