Quantitative exposure matrix for asphalt fume, total particulate matter, and respirable crystalline silica among roofing and asphalt manufacturing workers

Abstract

This paper summarizes available data on worker exposures to asphalt fume (soluble fraction), total particulate matter, and respirable crystalline silica (quartz) [hereinafter RCS] over a 30-year period in Owens Corning’s asphalt production and roofing manufacturing plants. For the period 1977 through 2006, the air-monitoring database contains more than 1,400 personal samples for asphalt fume (soluble fraction), 2,400 personal samples for total particulate, and 1,300 personal samples for RCS. Unique process-job categories were identified for the asphalt production and roofing shingle manufacturing plants. Quantitative exposures were tabulated by agent, process-job, and calendar period to form an exposure matrix for use in subsequent epidemiologic studies of the respiratory health of these workers. Analysis of time trends in exposure data shows substantial and statistically significant exposure reductions for asphalt fume (soluble fraction), total particulate matter, and respirable crystalline silica at Owens Corning plants. Cumulative distribution plots for the most recent sampling period (2001–2006) show that 95% of the asphalt fume (soluble fraction) measurements were less than 0.25 mg/m³; 95% of the total particulate measurements were less than 2.2 mg/m³; and 95% of the RCS measurements were less than 0.05 mg/m³. Several recommendations are offered to improve the design of future monitoring efforts.

Keywords::

• Asphalt fume
• total particulate
• respirable crystalline silica (quartz)
• historical exposure analysis
• product stewardship
• built-up roofing asphalt

Acknowledgements

The many contributions of Robert Holler, Paul Langford, Joe Cendro, and Klaus Rosinski are gratefully acknowledged. We also acknowledge the helpful comments of anonymous reviewers whose comments added clarity and focus to the manuscript.

Declaration of interest: This project was funded by Owens Corning. The findings, conclusions, and recommendations of this paper are those of the authors alone and do not necessarily represent the interpretations of Owens Corning.

Notes

¹See http://osha.europa.eu/en/seminars/belgian-eu-presidency-seminar/speech-venues/workshop-3-maintenance-and-dangerous-substances/overview-of-workers2019-exposure-while-performing-repair-and-maintenance-work or http://www.cefic.org/Documents/ResponsibleCare/RC%20Forum%202011/7.EU-OSHA%20Campaign%20on%20Safe%20Maintenance%20-%20Katalin%20Sas.pdf.

²Note that very few samples of RCS were collected at asphalt production plants. This is because silica-containing materials are not used in asphalt production. However, sand is used in the manufacture of roofing materials.