The Health Hazard Evaluation Program received a request from a gray and ductile iron foundry. The employer was seeking guidance on noise control solutions for the molding, knockoff, grinding, and inspection areas. We visited the facility in April 2011 to discuss concerns with managers and employees; observe work activities and processes; measure employees' noise exposures, sound levels, and noise frequencies; and assess potential noise control options. Noise sources included striking metal with sledgehammers; cutting metal with chop saws; and smoothing metal edges with stationary abrasive stone grinders, hand-held pneumatic chisels and grinders, and shotblast tumblers. The foundry operated three shifts per day and had about 200 employees. Employees worked 10-hour shifts. Noise levels in many work areas were very high (above 100 decibels). Metal-to-metal contact, grinders and saws, compressed air, and vibration caused most noise from equipment and shaker conveyors. All employees we monitored were exposed to noise above noise exposure limits, and some employees' noise exposures were above 100 decibels, A-weighted. Some employees did not insert their foam earplugs properly. We recommended the foundry install controls to reduce noise, implement a long-term plan to purchase new equipment that generates less noise, require employees working in areas where noise exposures are above 100 decibels, A-weighted to wear earplugs and earmuffs, and use National Institute for Occupational Safety and Health recommendations for evaluating employees' hearing tests. We recommended employees wear hearing protection properly and tell their doctor that they work in areas with high noise levels and about hearing problems they have. Recommended citation for this report: NIOSH [2015]. Health hazard evaluation report: evaluation of noise exposures at a grayand ductile iron foundry. By Brueck SE. Cincinnati, OH: U.S. Department of Health and Human Services, Centers for Disease Control and Prevention, National Institute for Occupational Safety and Health, NIOSH HHE Report No. 2011-0087-3241. NIOSHTIC no. 20046652

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