Changes in peroxisome number and volume after exposure to various mixtures of polyCTFE

Abstract

Polychlorotrifluoroethylene (POLYCTFE) is a candidate base stock for a nonflammable hydraulic fluid under consideration for advanced aircraft and ground systems. PolyCTFE consists of oligomers with 3 and 4 units, trimer and tetramer, blended to achieve a viscosity of 3.1 (3.1 oil). Although acutely nontoxic, repeated inhalation exposure of rats to the 3.1 oil resulted in hepatocytomegaly with an increased number of peroxisomes identified by counts made on photomicrographs. A comparative study was conducted to evaluate the relative toxicity of the different oligomers and two formulations of 3.1 oil. In rats pure tetramer was toxic while pure trimer had little toxicity. The standard 3.1 oil formulation of PolyCTFE (C6:C8 oil), consisting of trimer and tetramer in a ratio of 55:45, produced toxicity similar to the pure tetramer. The 3.1 oil formulation of PolyCTFE, consisting of trimer and high molecular weight oligomers in the C10 range with a ratio of 95:5 (C6 oil), produced toxicity similar to pure trimer. The objective of this study was to quantitate by number and volume peroxisomes in hepatocytes from the comparative study.