A document published by NIOSH in March focuses on engineering controls for pavement-milling machines that can be used to reduce occupational exposures to respirable crystalline silica. The publication, which was developed through the Silica/Asphalt Milling Machine Partnership, represents more than ten years of collaborative research by labor, industry, and government to reduce silica exposure during asphalt pavement milling in highway construction. 

According to NIOSH, approximately 367,000 U.S. workers employed in highway, street, and bridge construction are at risk of exposure to respirable crystalline silica. Many of these workers use or work in close proximity to cold-milling machines, which have toothed, rotating cutters that grind and remove asphalt pavement. The document provides recommendations to reduce silica dust exposure, including ventilation controls in addition to water sprays used to cool the cutting teeth of the milling machines.

The new publication also includes case studies in which NIOSH and its partners evaluated the effectiveness of changes in water spray applications on multiple job sites. Studies showed that worker exposure to silica from asphalt milling operations was lessened when machines used this dust control approach.

View the publication on NIOSH’s website.

The Silica/Asphalt Milling Machine Partnership was formed in 2003 and is coordinated by the National Asphalt Pavement Association.