The subject of the paper is the experience with a novel and field-proven method for the enhanced control of transient emissions from rotary kiln incinerators using oxygen enrichment. When high-BTU content wastes are fed into rotary kiln incinerators in an intermittent mode (typical of ram feed systems), the transient combustion behavior of these materials creates unsteady releases of combustible gases which may momentarily deplete the oxygen content of kiln gases. These temporary oxygen-deficient conditions could cause the release of products of incomplete combustion (PICs). Release of PICs from incinerators has raised public concern and has been the subject of research projects sponsored by the EPA. The enhanced control of transient emissions was demonstrated by the field operation of the EPA Mobile Incineration System (MIS) at the Denney Farm Superfund Site in McDowell, Missouri. During the field operation of the MIS, large quantities of high-BTU content wastes were burned periodically. These materials were ram-fed into the rotary kiln at a frequency of about twice a minute. To respond to the transient oxygen demand resulting from the burning of these materials, a unique oxygen feedforward-feedback control logic was designed into the LINDE Oxygen Combustion System (OCS) which was retrofitted into the MIS in 1987. After implementation of the OCS, transient upset conditions were significantly reduced during the operation of the MIS. Low NOx emissions were also achieved.