AIHA Fall Conference Template The Chartered Society for Worker Health Protection OH2016 25-28 April 2016 Glasgow, Scotland Session 7b Asbestos Wednesday, April 27, 2016 Brakes and Clutches: Maintaining and Repairing Interacting Surfaces. Fred W Boelter, CIH, PE, BCEE, FAIHA Jacob Persky, MPH, CIH RHP Risk Management Inc.
James Watt William Murdoch Scottish inventor Watt steam engine 1775 Scottish inventor Steam road locomotive 1784 2
Hold, Protect, Transfer, Stop - Hold - Clamps to Prevent Rotation - Protect Slip Clutch - Transfer Transmission Clutch - Stop - Rotating Wheel 3
Railroad Signal Shop Switch Machine Brake Shoes Holds in place motor drum Solenoid released Field adjusted Often never replaced over life of machine Possibly replaced but not relined ND-65% chrysotile by PLM 4
Railroad Signal Shop Switch Machine Slip Clutch Protects w/ fiber discs Slip Clutch Always engaged Slips to protect machine Maybe field replaced but never field serviced Shop rebuilt occasionally ND-80% chrysotile by PLM 5
Slip Clutch Unit Replacement Statistical Function Full-Shift Personal Samples NIOSH 7400 PCM (total f/cc) 8-Hour TWA Personal Samples NIOSH 7402 TEM (Asbestos f/cc) 8-Hour TWA Personal Samples MAXIMUM 0.024 < 0.006 MINIMUM 0.016 < 0.006 MEAN 0.020 < 0.006 S.D. 0.006 < 0.000 COUNT 2 2 Statistical Function Excursion Limit (aka STEL) Personal Samples NIOSH 7400 PCM (total f/cc) 30-Minute Personal Samples NIOSH 7402 TEM (Asbestos f/cc) 30- Minute Personal Samples MAXIMUM 0.065 < 0.045 MINIMUM <0.045 < 0.045 MEAN 0.050 < 0.045 S.D. 0.009 0.000 COUNT 8 8 6
Slip Clutch Rebuilding 7
Slip Clutch Rebuilding Statistical Function Full-Shift Personal Samples NIOSH 7400 PCM (total f/cc) 8-Hour TWA Personal Samples NIOSH 7402 TEM (Asbestos f/cc) 8-Hour TWA Personal Samples MAXIMUM 0.044 0.009 MINIMUM 0.029 <0.006 MEAN 0.037 0.007 S.D. 0.011 0.002 COUNT 2 2 Statistical Function Excursion Limit (aka STEL) Personal Samples NIOSH 7400 PCM (total f/cc) 30-Minute Personal Samples NIOSH 7402 TEM (Asbestos f/cc) 30-Minute Personal Samples MAXIMUM 0.106 < 0.045 MINIMUM <0.045 < 0.045 MEAN 0.050 < 0.045 S.D. 0.015 0.000 COUNT 18 18 8
Heavy Machines Clutch (transfer) Brakes (stop) 9
D8 Track Bulldozer Cleaning, scraping, compressed air cleaning of drive and driven plates, hand riveting 30-min EL 0.17 asb f/cc 8-hrTWA 0.052 asb f/cc 10
955 Track Loader Drilling Brake Pad Lining, Brake Relining with Rivets 30-min EL <0.038 asb f/cc 8-hr TWA 0.016 asb f/cc 30-min EL <0.043 asb f/cc 8-hr TWA 0.016 asb f/cc 11
930 Wheeled Loader Disc brake pad removal, Disc brake reinstallation 30-min EL <0.044 asb f/cc 8-hr TWA 0.024 asb f/cc 30-min EL <0.044 asb f/cc 8-hr TWA 0.024 asb f/cc 12
12E Motor Grader Brake shoe replacement, Brake drum adjustment 30-min EL <0.045 asb f/cc 8-hr TWA <0.005 asb f/cc 30-min EL <0.044 asb f/cc 8-hr TWA 0.028 asb f/cc 13
Dust and Debris 15 samples were taken of debris and scrapings from friction products 6 samples had asbestos content of <1% No asbestos was detected in the other 9 samples 14
Heavy Machines Statistical Function All Friction Tasks Full-Shift Personal Samples NIOSH 7400/7402 PCM (asbestos f/cc) 8-Hour TWA Personal Samples MAXIMUM 0.052 MINIMUM <0.005 AVERAGE 0.024 S.D. 0.015 COUNT 7 All Friction Tasks Excursion Limit (aka STEL) Personal Samples Statistical NIOSH 7400/7402 PCM (asbestos f/cc) Function 30-Minute Personal Samples MAXIMUM 0.17 MINIMUM <0.038 AVERAGE 0.061 S.D. 0.048 COUNT 7 15
Power Transmission Clutch (transfer) 16
Transmission Clutch removal Deep pitting Hot spot 17
Statistical Function Transmission Clutch Data Clutch Servicing Full-Shift Personal Samples NIOSH 7400 PCM (total f/cc) 8-Hour TWA Personal Samples NIOSH 7402 TEM (Asbestos f/cc) 8-Hour TWA Personal Samples MAXIMUM 0.056 <0.006 MINIMUM 0.046 <0.006 AVERAGE 0.051 <0.006 S.D. 0.007 0 COUNT 2 2 Clutch Servicing Excursion Limit (aka STEL) Personal Samples Statistical Function NIOSH 7400 PCM (total f/cc) 30-Minute Personal Samples NIOSH 7402 TEM (Asbestos f/cc) 30-Minute Personal Samples MAXIMUM 0.176 <0.045 MINIMUM 0.074 <0.045 AVERAGE 0.112 <0.045 S.D. 0.032 0 COUNT 8 8 18
Arc Grinding Brake Shoes (stop) 19
the Drum and the Shoes Turning the Drum Gauging the Drum Arcing the Primary and Secondary Shoes Verifying the Shoe Fits 20
The Good and the Bad of Arcing Properly Arced Irreparably Damaged 21
Cleaning Drum Turnings and Arcing Dust Mostly Metal Turnings Sanded Off Brake Shoe Lining 22
Arc Grinding Statistical Function Arc Grinding Full-Shift Personal Samples NIOSH 7400 PCM (total f/cc) 8-Hour TWA Personal Samples MAXIMUM 0.019 MINIMUM 0.018 AVERAGE 0.018 S.D. 0 COUNT 2 Arc Grinding Excursion Limit (aka STEL) Personal Samples Statistical NIOSH 7400 PCM (total f/cc) Function 30-Minute Personal Samples MAXIMUM 0.086 MINIMUM <0.045 AVERAGE 0.051 S.D. 0.011 COUNT 32 23
Other Friction Studies (8-hr TWA f/cc) Maximum 0.052 PCME Mean 0.018 PCME Minimum 0.005 f/cc PCME Our Aggressive Activity Data 24
Conclusions Aggressive repair and maintenance of asbestoscontaining friction products results in exposures well below both OSHA s standard for an 8-hour TWA and the 30-minute EL Aggressive activities such as scraping, hammering, drilling, abrasive cutting, riveting, and cleaning using a die grinder or compressed air on materials containing asbestos did not yield significant concentrations based on a STEL nor contribute meaningfully to the 8-hr TWA Studies regarding exposures are challenging to conduct and when examining historical products and methods, it is critical to have the parts, vintage equipment, and knowledgeable tradespersons. 25
Thank You. Fred W Boelter, CIH, PE, BCEE, FAIHA RHP Risk Management Inc. Boise, Idaho, USA fboelter@rhprisk.com +1 208 258 7478 Jacob Persky, MPH, CIH RHP Risk Management Inc. Chicago, Illinois, USA jpersky@rhprisk.com +1 773 867 6001