Evaluation of airborne asbestos concentrations associated with the maintenance of brakes on an industrial overhead crane

Abstract

Objectives

To evaluate potential airborne asbestos exposures during brake maintenance and repair activities on a P&H overhead crane, and during subsequent handling of the mechanic’s clothing.

Methods

Personal (n = 27) and area (n = 61) airborne fiber concentrations were measured during brake tests, removal, hand sanding, compressed air use, removal and reattachment of chrysotile-containing brake linings, and reinstallation of the brake linings. The mechanic’s clothing was used to measure potential exposure during clothes handling.

Results

All brake linings contained between 19.9% to 52.4% chrysotile asbestos. No amphibole fibers were detected in any bulk or airborne samples. The average full-shift airborne chrysotile concentration was 0.035 f/cc (PCM-equivalent asbestos-specific fibers, or PCME). Average task-based personal air samples collected during brake maintenance, sanding, compressed air use, and brake lining removal tasks ranged from 0 to 0.48 f/cc (PCME). The calculated 30-minute time-weighted average (TWA) airborne chrysotile concentration associated with 5-15 minutes of clothes handling was 0–0.035 f/cc PCME.

Conclusion

The results indicated that personal and area TWA fiber concentrations measured during all crane brake maintenance and clothes handling tasks were below the current OSHA 8-h TWA Permissible Exposure Limit for asbestos of 0.1 f/cc. Further, no airborne asbestos fibers were measured during routine brake maintenance tasks following the manufacturer’s maintenance manual procedures. All short-term airborne chrysotile concentrations measured during non-routine tasks were below the current 30-minute OSHA excursion limit for asbestos of 1 f/cc. This study adds to the available data regarding chrysotile exposure potential during maintenance on overhead cranes.

Keywords:

• Asbestos
• inhalation
• chrysotile
• crane
• brake maintenance
• exposure assessment
• heavy equipment

Acknowledgements

The data collection and laboratory analysis portion of this study was funded by P&H Cranes. The writing and submission of the manuscript was not funded by P&H Cranes and was solely supported by the employer of the authors, Insight Exposure and Risk Sciences Group.

Data availability statement

The data that support the findings of this study are available from the corresponding author, JS, upon reasonable request.

Disclosure statement

All the authors (TF, SB, BS, HA, SD, SG, and JS) are employed by Insight Exposure & Risk Sciences, a consulting firm that provides scientific advice to entities including governments, corporations, law firms, and various scientific/professional organizations. Four of the authors (SD, SG, JS, and BS) have previously served as an expert in litigation that involved asbestos exposure allegations. The data collection and laboratory analysis portion of this study was funded by P&H Cranes. P&H Cranes did not review or provide input on the article or data analysis prior to submission or revision.