Asbestos exposure from the overhaul of a Pratt & Whitney R2800 engine

This study assessed the asbestos exposures of airplane piston engine mechanics while performing overhaul work on a Pratt & Whitney R2800 radial engine, with tools and practices in use since the time these engines were manufactured. Approximately 40% of the bulk samples collected during this test were found to contain chrysotile. Air samples were collected during the overhaul and were analyzed by phase contrast microscopy (PCM) and transmission electron microscopy (TEM). The average worker exposure during disassembly was 0.0272 f/ml (PCM) and ranged from 0.0013 to 0.1240 f/ml (PCM) during an average sample collection time of 188 min. The average worker exposure during reassembly was 0.0198 f/ml (PCM) and ranged from 0.0055 to 0.0913 f/ml (PCM) during an average sample collection time of 222 min. Only one worker sample (during reassembly) was found to contain asbestos at a concentration of 0.0012 f/ml (PCME). Similar results should be found in other aircraft piston engines that use metal clad and non-friable asbestos gaskets, which are the current standard in aircraft piston engines.