This study was designed to accomplish two primary objectives: (1) to compare two test methods commonly used to evaluate toxicity of inhaled air pollutants, and (2) to observe the response as measured by each of the methods, of pulmonary alveolar macrophages exposed to 2μg hexavalent chromium. The firs t method evaluated featured use of intratracheal injections to simulate live inhalation exposures, and the second required exposure of macrophages cultured on petri plates. Pulmonary alveolar macrophages harvested from Long Evans rats were used. The two cell function parameters measured in the evaluations were chemiluminescence and oxygen consumption (which was determined for cells at rest and during phagocytosis). These two tests have been shown to be sensitive indicators of macrophage damage. Results of CL output and oxygen consumption revealed the two methods were significantly different. Evaluation of macrophages from live animals treated with CrO3 or CaCrO4showed no differences between their respective untreated controls as determined by measurement of their chemiluminescence production or of oxygen consumption rates. Alveolar macrophages that were cultured in media during treatment with the same two forms of hexavalent chromium showed statistically significant differences from untreated controls. These comparisons indicate that choices of investigative toxicological models influence interpretation of data recorded.