Complete necropsies were done on all surviving rats on termination of the study. Similar examinations were done as quickly after death as possible on rats that died during the experiment. Three male rats and one female rat in test group I, four male rats and two female rats in test group II, five male rats and four female rats in test group III and all rats in test group IV died during the experiment. Acute pneumonia characterized by varying degrees of consolidation (Hepatization) was observed in rats that died shortly after exposure to the test material. Treated rats that survived to completion of the study were described as emaciated. Frequently, the lungs of these animals did not collapse when the thorax was opened. This suggests a chronic proliferative inflammatory response in the lungs of affected animals.