§ 63.1294 Standards for slabstock flexible polyurethane foam production—diisocyanate emissions.
Each new and existing slabstock affected source shall comply with the provisions of this section.
(a) Diisocyanate storage vessels. Diisocyanate storage vessels shall be equipped with either a system meeting the requirements in paragraph (a)(1) of this section, or a carbon adsorption system meeting the requirements of paragraph (a)(2) of this section.
(1) The storage vessel shall be equipped with a vapor return line from the storage vessel to the tank truck or rail car that is connected during unloading.
(i) During each unloading event, the vapor return line shall be inspected for leaks by visual, audible, or an instrumental detection method.
(ii) When a leak is detected, it shall be repaired as soon as practicable, but not later than the subsequent unloading event.