Document XxOzNO1G1vMw3wYb2Nq9qb5J

CONTENTS Abstract.......................................................................................................... iii Introduction..............................................................................................................1 .Brake Materials, Products, and Usage.......................... 2 Historical. Development of Friction Products..............................2 Requirements for Brake Linings...........................................................3 Types of Brake Linings and Manufacturing Processes.............. 6 Brake Lining and Repair and Maintenance Practices History......... 8 Selection of Facilities Surveyed..............................................................10 Description of Brake Servicing Operations........................................... 10 Sample Collection and Analysis Methods.............................. ...11 Airborne Samples........................................................................................11 Bulk Samples.................................................. 12 Work Practices Characterization.................................................. 13 Compressed Air Blow-off.....................................................................13 Compressed Air/Solvent Mist Blow-off......... ................................. 13 Dry Brushing................................................................................................ 13 Vet Brushing............................................................................... 13 Squirt-off...................... 13 Vacuum Cleaning.......................................................................................... 14 Survey Results and Discussion................................................. Asbestos Exposure Levels....................................................... .15 15 TEM Fiber Characterization........................................................... ...17 Bulk Brake Dust................................................................................. 21 Trace Metal Analysis.............................................................................. 21 Potential Health Effects from Asbestos Exposure..............................23 Summary....................................................................................................... 25 Conclusion.......................................................................................... 26 Recommendations............................ 28 Appendix A-References................................................................................. .A-l Appendix B-Description of Individuals Facilities......................... B-l Appendix C-Recommended Procedures for Asbestos Brake and Clutch Servicing...................................... .......................C-l TABLES 1. Fiber Air Sample Results......................................... 16 2. Comparison Between TEM & Optical MicroscopyAnalysis........... 18 3. Fiber Size Data.......................... 20 4. Trace Metal Analyses.................................................................................22