EMISSIONS FROM THE INCINERATION OF NERVE AGENT ROCKETS CONTAINING LOW-LEVEL PCBS

During a recent assessment of the obsolete nerve agent rocket stockpile, some of the shipping and firing tubes encasing the rockets were found to contain low levels of polychlorinated biphenyls (PCBs) within the tube's fiberglass matrix. In order to determine the environmental and regulatory impacts associated with incineration of these rockets, the Army conducted an incineration test in March 1986, using its existing pilot incineration system. Because the feedrate of PCBs to the incinerator was very low and because the background matrix of the stack gas samples was so complex, the approved EPA analytical procedure was not sensitive enough to demonstrate that the PCB emissions were less than the rates required by the Toxic Substances Control Act (TSCA) regulations. While the regulatory level of PCB emissions could not be demonstrated analytically, a health risk assessment based on ambient concentrations of PCBs from dispersion modeling demonstrated that the PCB emissions do not pose a significant health risk. Emissions of octachlorodibenzo-p-dioxin (OCDD) were detected, but the risk assessment found no significant health risk associated with OCDD ambient concentrations. No semivolatile, chlorinated organic compounds were identified in the stack gases, while a number of volatile, chlorinated organic compounds were. Again, no significant health risk was associated with these emissions.