§ 63.5345 How do I distinguish between the two upholstery product process operations?
(a) Product process operations that finish leather for use in automobile and furniture seat coverings are categorized as an upholstery product process operation. There are two upholstery product process operations subject to the requirements of this subpart—operations with less than 4 grams of finish add-on per square foot, and operations with 4 grams or more of finish add-on per square foot. You must distinguish between the two upholstery product process operations so that you can determine which HAP emission limit in Table 1 of this subpart applies to your affected source.
(b) You must determine finish add-on by calculating the difference in mass before and after the finishing process. You may use an empirical method to determine the amount of finish add-on applied during the finishing process, as described in paragraphs (b)(1) through (4) of this section: