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FHWA Bridge Coatings Technical Note: Personnel Protection During Bridge Paint Removal
From: Special Projects and Engineering Division, Office of Engineering Research and Development
Topic: Personnel Protection During Bridge Paint Removal
Description: Many steel bridges are currently in need of maintenance. Maintenance operations may range from small component replacement jobs to major maintenance activities including repainting. Many steel bridges in the highway system are coated with paint that contains toxic heavy metal pigments (e.g., lead, chromate) in varying concentrations. These metals can be hazardous to human health if inhaled or ingested in relatively small quantities in the form of dusts or fumes. It is important to take appropriate measures to protect workers and inspectors potentially exposed to these hazards. Protection measures are straight forward, and when followed, can protect personnel while allowing for safe and productive work.
Description of the Hazard:
Required measures for worker protection during occupational exposure to lead are covered in the OSHA Lead-in-Construction Standard, 29 CFR 1926.62. This standard addresses the following issues in detail:
Engineering Controls are any piece of equipment or modified maintenance procedure which reduces the hazardous dust exposure to workers. Examples are: ventilation equipment (dust collectors) attached to blasting containments; shrouds and vacuum attachments for power tools; and, alternative low-dusting surface preparation methods (e.g., wet abrasive blasting, high pressure water blasting, chemical stripping, etc.). All of these controls provide a benefit by reducing worker health risks. Each engineering control also has tradeoffs in cost, productivity, or quality of surface preparation (and, hence, durability of the new coating). Engineering controls should be applied as-practical without sacrificing the quality of the work and balancing associated costs.
Respirators come in various forms. Each type of respirator has a particular assigned protection factor. This is the factor of hazard reduction associated with the particular respirator. For example, a half-face mask with proper filters and properly fitted reduces the ambient hazard by a factor of 10X. A typical continuous-flow, supplied-air abrasive blasting helmet reduces the hazard by 25X, with certain models designed to provide 1000X protection. Although exposure levels vary from job to job, for abrasive blasting inside of containment, a 1000X rated respirator is generally required.3, 4 For workers outside of containment and for inspection personnel, a half-face, negative pressure respirator with HEPA (high efficiency particulate air) filters (usually bright pink in color) may be sufficient. Since exposure levels for workers vary greatly depending on worker job description, containment design and operation, and other site-specific conditions, respirator selection and use should consider these factors.
Hygiene Practices - Workers removing lead-containing paint from bridges will get fine lead dust on their skin and clothes. The key to hygiene practices is to eliminate inhalation and ingestion of that dust by the worker while on the jobsite and to keep the worker from taking the lead hazard off the jobsite to expose others in their personal vehicles or homes. This is best accomplished by using dedicated work clothes which remain on the jobsite and are either disposable or laundered separately; and by supplying reasonable washing facilities for workers to use before they eat, smoke, or leave the jobsite. Specific requirements for these hygiene facilities are contained in the OSHA standard for lead-in-construction.
Administrative Controls - Exposures to lead are measured for compliance purposes using an 8-hour, full shift average. Mixing "high-exposure" activities with "low-exposure" activities may reduce a particular worker’s or inspector’s overall exposure.
OSHA requires air and blood monitoring for workers exposed to lead. The OSHA "action level" for lead-in-air is an 8-hour average of 30 :g/m3. This action level will be exceeded by almost all abrasive blasting activities, and many power tool-cleaning and torch cutting or demolition activities. Once the action level is exceeded, the contractor must follow all of the guidance of the standard to maintain worker exposure below 50 :g/m3 (the Personal Exposure Limit).
Worker blood lead level monitoring is required. Blood levels above 50 :g/dL require removal of the worker from the hazard. Some States require contractors to report worker blood levels as a means for monitoring contractor compliance.
For further information, please contact a member of the Bridge Coatings Technology Outreach Team: Ron Andresen, FL-Cen.; Dan Brydl, IL Div.; Dave Calabrese, MI Div; Mark Clabaugh, FL-East; Dr. Shuang-Ling Chong, HNR-20; Carl Highsmith, Region 3; Joe Huerta, HNG-20; Bob Kogler, HNR-20; Mike Praul, ME Div.; Larry O’Donnell, MA Div.
TRT Terms: Metal bridges; Paint removal; Occupational safety