Cook installed emission controls prior to compliance deadlines in the Ethylene Oxide Sterilizer NESHAP, and performance tested either on or well ahead of performance test deadlines, and the performance tests showed compliance. However, Cook is using a control technology not contemplated by the rule, and therefore was required to submit an alternative monitoring plan to USEPA for approval prior to the performance test. Therefore, Cook was in violation of the monitoring and recordkeeping requirements of the NESHAP General Provisions and the Ethylene Oxide Sterilizer NESHAP. This Order requires Cook to come into compliance and conduct repeated performance testing to demonstrate compliance.