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The shakeout floor of a metal foundry is one of the loudest places any industrial worker will ever stand. Castings being knocked from molds at 115–130 dBA. Grinding and chipping operations clearing gates and risers at 100–118 dBA. Tumble blast cleaning machines running 12 hours a day at 112 dBA inside enclosed drums. Foundry work is extreme-intensity noise work, and the hearing conservation programs at many foundries have not kept pace with what that intensity legally and practically requires.
Soundtrace tracks occupational hearing loss data across metal foundry and casting operations. This guide covers the unique compliance challenges of foundry noise environments and what hearing conservation program designs actually work.
At 115 dBA, OSHA's permissible exposure limit is reached in 15 minutes. At 130 dBA, under 2 minutes. Shakeout operations routinely produce these levels at operator positions for entire shifts. OSHA 1910.95(b)(1) explicitly requires engineering and administrative controls where technically feasible before relying on HPDs. At foundries, that requirement is mandatory, and citations for failure to implement feasible controls at shakeout operations are a real and documented enforcement action.
Extreme noise is not confined to shakeout. It permeates the entire production floor: grinding and chipping stations, tumble blast cleaning, molding machines, and core knockout operations all exceed 90 dBA at nearby operator positions. A foundry worker on a full shift is typically exposed to sustained broadband noise above OSHA's action level from the moment they clock in. The workers' compensation exposure at foundries with poor longitudinal audiometric records is among the highest in manufacturing.
Foundry noise is intense, broadband, and pervasive. There is no position on a production floor that is reliably below OSHA's 85 dBA action level without specific engineering controls.
At 115–130 dBA, no combination of HPDs reduces exposure to safe levels for a full shift. OSHA 1910.95(b)(1) mandates feasible engineering and administrative controls before relying on HPDs. At levels exceeding 100 dBA, dual hearing protection is required. Foundries that have operated shakeout without these controls for decades are citation-ready.
The foundry sector's occupational hearing loss trend has followed the broader manufacturing pattern — a gradual rise since 2016, disrupted by the COVID testing gap in 2020, then accelerating post-pandemic as programs normalized.
Foundry hearing conservation programs fail at specific and predictable points: inadequate engineering controls, insufficient dual-protection implementation, heat-stress-driven HPD non-compliance, and infrequent testing that misses rapid threshold progression.
OSHA 1910.95(b)(1) requires feasible engineering and administrative controls when noise exceeds the permissible exposure limit. At 115 dBA, the PEL is reached in 15 minutes. Engineering controls — equipment enclosures, remote operation, vibration isolation, job rotation — must be implemented to the extent technically feasible before relying on hearing protection.
Under OSHA Appendix B to 1910.95, when noise levels exceed 100 dBA, dual hearing protection is required. The combined NRR is calculated by taking the higher of the two NRR values and adding 5 dB. At 130 dBA, even optimal dual protection may produce an estimated ear exposure above 90 dBA, reinforcing the requirement for engineering controls.
Yes. Maintenance technicians who work in foundry production areas are covered by 1910.95 if their noise exposure meets or exceeds 85 dBA TWA. Maintenance workers who enter tumble blast housings, grinding rooms, and shakeout areas often have the highest individual exposures on the floor and are the most frequently missed by standard program enrollment.
Soundtrace puts audiometric testing in-house so workers can be tested year-round, not once a year. Automated STS detection. Cloud-based records. Built for high-noise industrial environments.
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