Table 3. Performance Factors Checklist for Measures to Control Worker Exposures to Air Contaminants in Foundries
Job Category: Target Air Contaminant Exposures (follow up from Step 1 Exposure Hazard Assessment):
Instructions 1. Complete this worksheet for each exposure control option identified in Table 2. 2. Check all boxes which are expected to be satisfied by this option.
Effectively addresses potential exposure sources. Can feasibly be installed in this operation. Does not create new hazards to safety and health. Does not disrupt the capability to produce a quality product. Is acceptable to workers. Standards of performance are defined and performance monitoring methods are established. Can readily perform reliably with periodic maintenance and worker training. Reduces/eliminates the sources of air contaminants. Reduces/eliminates the need for respiratory protection.
Performance Factor Comments
they are capable and performing at their design parameters. Selecting exposure control measures
for metalcasting applications based on a simple ranking provides insufficient guidance to address the complexities of the foundry work environment: • In metalcasting operations, several sources of air contamination may impact the exposure levels of particular workers, resulting in the potential need for a strategy involv- ing the interworking of multiple control measure types.
• The processes, equipment and materials employed in casting production are not amenable to extensive changes to effectively accomplish exposure reduction to a significant extent through elimina- tion and substitution.
• For many current metalcasting operations which extend across wide areas of the plant, may be mobile in nature or require extensive worker involvement, effective engineering control measures such as ventila- tion have not been developed to the extent that they can address many current process operations.
• Ventilation control of air con-
taminants at or near their sources is potentially the most effective form of ventilation. However, this exposure control method would not apply if its application caused the creation of a new safety or health hazard, interference with produc- tion, or unacceptability to workers.
Performance-Based Approach A stepwise performance-based
approach has been formulated for use in directing efforts to reduce worker exposures to air contami- nants in foundries, with guidance starting at initial exposure hazard assessment through evaluation of the performance of installed expo- sure control measures.
ACTION ITEM 1: CONDUCT AN EXPOSURE HAZARD ASSESSMENT Objectives:
• Determine compliance status with standards for worker expo- sures to air contaminants.
• Identify jobs where exposure controls need improvement. An assessment should be done that considers the risk to workers
(both severity of potential harm and likelihood of exposure.) Poorly understood single expo-
sure measurements are not a sound basis for risk or controls deci- sions. The exposure hazard assess- ment should take into account the expected variability in exposures measured in metalcasting environ- ments. NIOSH has recommended a statistical method for analyz- ing exposure results in industrial environments which takes variability of exposure sampling results into account. Variability in exposure sampling results can occur from the following sources: • Normal metalcasting operations that occur regularly and have expected outcomes.
• Situations occurring in metalcast- ing operations that deviate from the norm.
• Differences among workers. • Differences in the work environment.
ACTION ITEM 2: DETERMINE THE SOURCES OF AIR CON- TAMINATION Objectives:
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