(a) The provisions of this section apply to the control of air emissions from process vents for which Sec. 63.683(c)(1)(i) of this subpart references the use of this section for such air emission control.
(b) The owner or operator must route the vent stream from each affected process vent through a closed-vent system to a control device that meets the standards specified in Sec. 63.693 of this subpart. For the purpose of complying with this paragraph (b), a primary condenser is not a control device; however, a second condenser or other organic recovery device that is operated downstream of the primary condenser is considered a control device. [64 FR 38970, July 20, 1999]