EPPU
Elastomer product process unit (EPPU) means a collection of equipment assembled and connected by hard-piping or duct work, used to process raw materials and to manufacture an elastomer product as its primary product. This collection of equipment includes unit operations; recovery operations equipment; process vents; storage vessels, as determined in 63.480; equipment that is identified in 63.149; and the equipment that is subject to the equipment leak provisions as specified in 63.502. Utilities, lines and equipment not containing process fluids, and other non-process lines, such as heating and cooling systems which do not combine their materials with those in the processes they serve, are not part of an elastomer product process unit. An elastomer product process unit consists of more than one unit operation.
Source
40 CFR § 63.482
Scoping language
The following terms used in this subpart shall have the meaning given them in 63.2, 63.101, 63.111, 63.161, or the Act, as specified after each term: