| Abstract: | The information presented in this paper is directed to persons concerned with control of exhaust odors from diesel-engine-powered vehicles. This paper summarizes projects sponsored by the Environmental Protection Agency (EPA) over the past years in the field of diesel-exhaust odor. These investigations have concentrated on developing measurement methods for quantifying different odor levels, evaluating various odor control methods, and evaluating public opinions of such odors. A human panel method using odor reference standards has been found suitable to measure these odor levels. In addition to this technique, chemical characterization work has been sponsored under a project jointly sponsored by the Coordinating Research Council and the EPA to isolate and identify those species responsible for the odor. Knowledge of these odorous compounds and the techniques necessary to isolate them should lead to development of a chemical method to measure this type of odor, in place of human panelists. Such basic information would also lead to developing control techniques to minimize this odor. Several control techniques were evaluated for diesel exhaust odor. To date, the most effective method is an improved needle injector for use in the Detroit Diesel type E 6V-71 engine commonly used in buses. Finally, public reaction to diesel-engine-exhaust odor has been measured. It has been found that a systematic relationship exists between increasing public objections and increasing diesel odor intensity. |
