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When worker noise exposure exceeds OSHA's permissible exposure limit (PEL) of 90 dBA TWA, hearing protection alone is not enough—OSHA requires that employers implement feasible engineering and administrative controls to actually reduce noise at the source. This guide covers what OSHA requires, the types of controls that work, and how to prioritize implementation.
Soundtrace tracks noise exposure against the PEL in real time, flagging when engineering control assessments are required and documenting the results of implemented controls.
Under 1910.95(b)(1), employers must implement feasible engineering and administrative controls when any employee's noise exposure exceeds the 90 dBA PEL. Hearing protection devices may supplement controls but cannot substitute for them when feasible controls exist.
Many employers with workers at 92–95 dBA TWA simply issue higher-NRR earplugs and consider the matter resolved. This approach is a citable violation of 1910.95(b)(1). OSHA requires a documented feasibility assessment for engineering controls. If controls are feasible, they must be implemented. HPDs are the last line of defense, not the first response to a PEL exceedance.
Exceeding the PEL requires a documented engineering control assessment. Issuing earplugs without that assessment is not OSHA-compliant—even if the earplugs provide adequate attenuation to protect the worker.
Remove the noise source entirely. Examples: eliminating an unnecessary compressed air blow-off, removing a redundant conveyor, automating a manually-operated high-noise task.
Replace the noise-generating equipment with a quieter alternative. Examples: replacing pneumatic tools with electric equivalents, switching from impact to compression fastening.
Modify the equipment or environment to reduce noise transmission. Includes enclosures, barriers, vibration isolation, damping, and acoustic treatment.
Reduce exposure duration through scheduling, worker rotation, or restricting access to high-noise areas.
HPDs protect workers from residual exposure after controls have been applied. Cannot substitute for engineering controls at the PEL.
Sound-absorbing enclosures around high-noise machinery contain noise at the source. Full enclosures can achieve 10–20 dB reduction; partial enclosures 3–8 dB.
Typical reduction: 5–20 dBAnti-vibration mounts, isolation pads, and constrained-layer damping materials. Particularly effective on stamping presses, conveyor frames, and compressors.
Typical reduction: 3–8 dBFreestanding or fixed barriers between noise sources and worker positions block direct sound transmission. Effectiveness depends on barrier height, mass, and positioning.
Typical reduction: 5–15 dBSound-absorbing materials on ceilings, walls, and baffles reduce reverberant noise that accumulates in hard-surfaced production areas.
Typical reduction: 2–6 dBElectric tools instead of pneumatic, lower-speed gear drives, rubber-lined conveyor components. Most cost-effective at equipment replacement or facility expansion cycles.
Typical reduction: 5–15 dBWorn bearings, loose panels, and dry couplings all add noise. A structured PM program targeting noise-generating wear can achieve 3–5 dB reduction with no capital investment.
Typical reduction: 2–5 dBA control is technically feasible if it can achieve meaningful noise reduction for the source type involved. It is economically feasible if the cost is not so high as to threaten business viability. Employers cannot simply assert that controls are infeasible without documentation. A feasibility determination should include: the noise source, available control options, their expected effectiveness, and estimated cost.
If engineering controls do not reduce exposure to or below the PEL, administrative controls must also be implemented.
Distribute high-noise exposure across multiple workers to prevent any individual from accumulating a full-shift dose.
Schedule quiet tasks during high-noise equipment cycles to reduce exposure duration for specific workers each shift.
Position workstations at the maximum feasible distance from dominant noise sources. Noise decreases ~6 dB for each doubling of distance.
Limit time spent in high-noise zones to only the time necessary for the task. Prevent unnecessary transit through high-noise areas.
A compliant program should include: a description of each noise source exceeding the PEL; a list of feasible controls considered; the controls implemented; the noise reduction achieved (verified by post-control measurement); and the date of implementation and next scheduled reassessment.
Soundtrace flags PEL exceedances in real time, triggers engineering control review workflows, and documents post-control measurements alongside the original exposure data.
Book a DemoGet a quote for your facility →Under 1910.95(b)(1), engineering and administrative controls are required whenever any employee's noise exposure exceeds the 90 dBA PEL, provided that feasible controls exist. Hearing protection cannot substitute for engineering controls when controls are technically and economically feasible.
Common engineering controls include machine enclosures (5–20 dB reduction), vibration isolation and damping (3–8 dB), acoustic barriers (5–15 dB), room acoustic treatment (2–6 dB), substitution of quieter equipment (5–15 dB), and noise-focused preventive maintenance (2–5 dB).
OSHA considers controls feasible if they are both technically feasible (capable of achieving meaningful noise reduction) and economically feasible (the cost does not threaten business viability). Employers must document their feasibility assessment in writing. Verbal claims of infeasibility are not defensible during an OSHA inspection.