Evaluation of Airborne Asbestos Concentrations Associated with the Operation and Maintenance of Brakes and Clutches on Nonautomated Heavy Equipment
Table 1
Overview of air samples collected during crane maintenanceA.
Day
Crane maintenance
Additional maintenance tasksB
Personal samples
Full-shift area samples (one sample/day)
Number of task-based area samples (1.5 m from workbench, 18–21 m from cranes)C
1
Clutch band removed from 22B crane, relined, and almost completely reinstalled; shop cleanup
None
1 full-shift; 2 partial-shift; 5 task-based
1.5 m from 22B crane; 4.6 m from 22B crane; 9.1 m from 22B crane; 4.6 m from workbench; 9.6 m from workbench;
4 samples
2
Finished reinstalling 22B clutch band; brake bands removed from 22B crane, relined, and reinstalled; shop cleanup
(1) Compressed air blowoff of brake linings (2) Compressed air blowoff of clutch linings
1 full-shift; 2 partial-shift; 9 task-based
1.5 m from 22B crane; 4.6 m from 22B crane; 9.1 m from 22B crane; 4.6 m from workbench; 9.6 m from workbench;
9 samples
3
Clutch and brake bands removed from 15B crane, and clutch bands relined; shop cleanup
(3) Sanded brake linings and blew off with compressed air (4) Removed brake linings, cleaned and painted brake bands (5) Cleaned brake lining surface with electric wire brush (6) Measured, cut, and installed woven brake linings
1 full-shift; 2 partial-shift; 8 task-based
1.5 m from 15B crane; 4.6 m from 15B crane; 9.1 m from 15B crane; 4.6 m from workbench; 9.6 m from workbench;
8 samples
ASamples were collected in accordance with the NIOSH methods 7400 and 7402. Flow rates were approximately 1-2 L/min for personal samples and 5 L/min for area samples. BTasks performed on brake and clutch bands that were removed from the crane prior to the start of the study. CTask-based area samples were collected 1.5 m from workbench, including during tasks performed on the cranes which were 18.3 to 21.3 m from the stationary sampler.