40 C.F.R. § 63.493
Owners and operators of new and existing affected sources shall comply with the requirements in §§ 63.494 through 63.500 . Owners and operators of affected sources whose only elastomer products are latex products, liquid rubber products, or products produced in a gas-phased reaction process, are not subject to the provisions of §§ 63.494 through 63.500 . If latex or liquid rubber products are produced in an affected source that also produces another elastomer product, the provisions of §§ 63.494 through 63.500 do not apply to the back-end operations dedicated to the production of one or more latex products, or to the back-end operations during the production of a latex product. Table 8 to this subpart contains a summary of compliance alternative requirements for the emission limits in § 63.494(a)(1)-(3) and associated requirements.
40 C.F.R. §63.493