On April 7, 2021, U.S. EPA issued a Finding of Violations that alleged violations of the National Emission Standards for Hazardous Air Pollutants
from the Synthetic Organic Chemical Manufacturing Industry (the HON) and the National Emission Standards for Hazardous Air Pollutants from Hazardous Waste Combustors (the HWC MACT). In brief, Vertellus violated various leak detection and repair provisions in the HON and the carbon monoxide emission standard in the HWC MACT. Vertellus informed EPA representatives that on or around December 15, 2023, the company idled the Facility and ceased burning hazardous waste in its boilers. Consequently, Vertellus is not operating at the Facility any emission units subject to the Hazardous Organic NESHAP and the HWC MACT.