Managing Silica Dust When Grinding Irregular Surfaces

Ernest N. Morial New Orleans Convention Center 

When grinding rounded or non-flat concrete surfaces, current commercially available vacuum systems fail to contain silica dust. The rigid shroud on these tool-mounted systems cannot maintain a seal, allowing large amounts of airborne dust to be released directly into the operator's breathing zone. While wet grinding systems, which use a continuous water mist to control dust at the source to effectively mitigate this hazard, their commercial availability for concrete finishing applications is limited. Consequently, manufacturers have not provided adequate engineering controls to suppress or capture silica-containing dust during the detailing of non-flat concrete infrastructure.

Employees faced high silica exposure, reaching levels 38.8 times the ACGIH TLV, primarily due to the limited capture efficiency of HEPA-filtered dust collectors. A key challenge was the failure of conventional local exhaust ventilation for concrete grinding on non-flat surfaces. Commercially available shrouds could not properly conform to these shapes, leading to inadequate suction and high employee dust exposure. To address this issue, wet grinding methods were introduced at a major infrastructure manufacturer. This approach has proven effective in real-world conditions, reducing personal silica exposure to a safe level below the ACGIH TLV. While this is currently the most effective and practical solution, the limited availability of suitable equipment means it may not be viable for every si

Kevin Beeunas graduated from Purdue University in 2017 and immediately joined the Liberty Mutual Risk Control group. As an Industrial Hygienist, Kevin advises all levels of customer organizations on occupational disease risk assessment and man processes. Further, Kevin is responsible for supporting customers by identifying exposure risk, evaluating workplace practices/procedures, and developing strategies to reduce the risk of occupational disease associated with various stressors through a var 

Dr Rob Agnew, Technical Director, Industrial Hygiene, Liberty Mutual Insurance 

Aerosol and airborne particulate monitoring

Exposure Assessment

Regulatory compliance

Risk assessment and management

Ventilation