Respondent owns and operates a global technology and specialty materials company operating in the production of vinyl acetate. Respondent operates the Facility in part to produce vinyl acetate in a reactor process. Vinyl acetate is identified at 40 C.F.R. Part 68.130 as a toxic regulated substance with a threshold quantity of 15,000 pounds. Respondent produces, stores, or handles vinyl acetate in an amount over the threshold quantity of 15,000 pounds in a process unit. The unit at Respondent’s facility is a covered process subject to RMP Program 3 requirements. Respondent’s covered process includes Azeotrope Distillation Column T-127, where crude vinyl acetate and water are separated from acetic acid and ethyl acetate. The crude vinyl acetate is separated from acetic acid through an evaporation and condensation process. As part of the distillation process the vinyl acetate vapor is transported by piping from the T-127 column through cooling water exchangers and then flows to a receiver vessel. The Facility employs a differential pressure transmitter located at the top of T-127 column and before the cooling water exchangers to monitor pressure across the column. The transmitter sends a reading to the unit’s control room. On October 1, 2015 Respondent reported a release of vinyl acetate from the covered process to the National Response Center. The report states that the release began on September27, 2015 but was not identified until October 1, 2015. During the four days the leak persisted, Respondent released 35,444 pounds of vinyl acetate.