An Assessment of Lead Controls for Torch Cutting and Rivet Removal on Steel Structures

The use of engineering and work practice controls to protect workers from lead-containing dusts and fumes generated during rehabilitation of steel structures is mandated by the Occupational Safety and Health Administration (OSHA) Lead in Construction Standard (1993). Because the implementation and assessment of controls can be problematic in the rugged and dynamic construction environment, industrial hygienists should understand the effectiveness and limitations of controls adopted. The present investigation assesses the efficacy of two controls to reduce lead exposure: paint removal prior to oxy-acetylene torch cutting of steel, and encapsulation of rivets prior to their removal. A task-based exposure assessment approach was used to evaluate these tasks at three sites. Exposures at one site without controls were compared to exposures at sites with controls. Comparison of the results via an analysis of variance (0.05 significance level) indicates that, for torch cutting, exposures at the control site were not significantly different from those at an uncontrolled site (p = 0.14). The results for rivet busting show no significant differences in exposures at the control site compared to the uncontrolled site (p = 0.08). Results are also presented from two control sites where work was done in enclosed spaces. Two main difficulties in applying the controls are explored: technical and managerial. Technical problems during torch cutting included the penetration of paint into the steel profile and the configuration of the structures. For rivet busting, working within an enclosure was an important factor. Management problems arose both from a lack of coordination among different contractors, and from a failure to provide day-to-day guidance and assessment of the control. Important components of a program to implement controls are preplanning and coordination of control implementation, frequent testing of control efficacy, and a method for timely intervention to correct deficiencies.

Keywords:

• Lead Exposure
• Task-BASED Exposure Assessment
• Bridge Rehabilitation
• Engineering Controls
• Work Practice Controls
• Construction Industry