The Health Hazard Evaluation Program received a request from a gray and ductile iron foundry. The employer was concerned about noise exposures in the knockoff areas of the facility. The foundry had seven knockoff areas where employees separated ductile iron castings from the metal riser and runner gating that remained attached following the casting process. We measured sound levels in the knockoff areas; they were very high. Metal-to-metal contact, shaker conveyors and other equipment, and vibration caused most noise. Employees' time-weighted average noise exposures in all of the knockoff jobs we monitored exceeded NIOSH and OSHA occupational exposure limits. Furthermore, time-weighted average noise exposures in all of the knockoff locations were greater than 100 decibels, A-weighted. We observed that most but not all employees working in these areas wore dual hearing protection as recommended by NIOSH and OSHA. Some employees did not fully insert their foam earplugs. We recommend installing engineering noise controls, improving acoustic barriers and treatments, maintaining equipment to eliminate unnecessary rattling from loose parts, and implementing a Buy Quiet program to help reduce noise exposures. Recommended citation for this report: NIOSH [2017]. Evaluation of noise exposures in the knockoff areas of an 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 Health Hazard Evaluation Report 2009-0224-3274, http://www.cdc.gov/niosh/hhe/reports/pdfs/2009-0224-3274.pdf. NIOSHTIC no. 20049531

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