This Notice of Violation is being issued by the New York State Department of Environmental Conservation (Department) to SABIC Innovative Plastics US, LLC in response to the unauthorized release of styrene vapor on September 1, 2020 at the facility. According to information obtained by the Department in conducting its on-going investigation of this incident, on September 1, 2020, an estimated quantity of 15,825 pounds of styrene vapor was released through the pressure relief valve and manway of a tank car stored at the facility. The tank car was received at the facility on May 26, 2020. However, later that day, facility personnel discovered that the tank car had a frozen vent valve plug. Therefore, the tank car was not unloaded and, in accordance with facility Standard Operating Procedures (SOPs), was relocated to the facility rail yard. The tank car remained in the facility rail yard with the load of styrene monomer since the date it was received. During this time,