The facility uses xylene as a cleaning agent to clean the reactors. Xylene is an extremely hazardous flammable substance, and is stored at the facility. On August 14, 2017, at 11:24am, an operator was cleaning the RX-2 reactor with xylene between tolling processes. The operator overfilled the reactor with xylene, leaving the reactor without a vapor space. The pressure increased causing the mpture disk to fail and release 4500 pounds of xylene into the atmosphere.
The primary root cause for the reactor upset was that the reactor was charged with an excess of xylene, leaving insufficient vapor space in the reactor. In addition, the reactor pressure transmitter for the reactor was set at an insufficient scan rate. As a result, the process control computer did not read any increase in pressure, failed to control the nitrogen pad pressure, and did not alarm the control room operator that an increase pressure was occurring.
Respondent calculated a total release of 4,500 pounds of mixed xylenes, including 1,616 pounds of p-Xylene, 1,803 pounds of m-Xylene, and 1,081 pounds of o-Xylene.
Pursuant to Section 112(r)(1) of the CAA, an owner/operator of a stationary source producing, processing, handling or storing substances listed pursuant to Section 112(r)(3) of the CAA, 42 U.S.C. § 7412(r)(3), or any other extremely hazardous substance, has a general duty to:
- identify hazards which may result from accidental releases of such substances using appropriate hazard assessment techniques;
- design and maintain a safe facility, taking such steps as are necessary to prevent releases; and
- minimize the consequences of accidental releases that do occur.
Complainant alleges that, when Respondent overfilled the reactor with xylene on August 14,2017, leading to the accidental release of xylene into the air, Respondent failed to maintain a safe facility, constituting a violation of the general duty clause in Section 112(r)(1) of the CAA.
In addition, Complainant alleges that Respondent’s failure to set the reactor pressure transmitter for the RX-2 reactor at a sufficient scan rate, leading to a failure to control the nitrogen pad pressure and a failure to indicate to the control room operator that pressure was increasing, was a failure to maintain a safe facility, constituting a violation of the general duty clause in Section 112(r)(1) of the CAA.