Facilities that recycle hazardous waste shall be exempt from subsection C of Section 2-7-113.1 and Section 2-7-115 of this title with regard to those units exclusively used in the recycling process. Off-site hazardous waste recycling facilities are subject to the requirements specified by the Oklahoma Hazardous Waste Management Act, the Oklahoma Uniform Environmental Permitting Act,¹ and rules promulgated thereunder, for a permit, and shall also meet design standards as promulgated by the Board. Such recycling facilities which were in existence on July 1, 1990, may but shall not be required to file a permit application pursuant to the provisions of the Oklahoma Hazardous Waste Management Act. A permit modification is not required for a permitted recycling facility to use new, improved, or better methods of recycling if the Department has approved the plans as being environmentally acceptable. An approved class 1 permit modification shall be required for a permitted recycling facility to increase the capacity of its recycling units or add new or different recycling units.