OSHA Noise Level Standards: Limits, Monitoring, and Penalties

OSHA’s noise level standards cap worker exposure at 90 dBA averaged over an eight-hour shift and require the employer to run a hearing conservation program once exposure reaches 85 dBA. Both numbers come from 29 CFR 1910.95, the general industry noise rule, and together they drive nearly every duty an employer has around workplace noise: monitoring, hearing tests, protectors, training, and records.¹

The Two Numbers That Drive Everything

The Permissible Exposure Limit (PEL) is 90 dBA as an eight-hour time-weighted average. Above that level, the employer has to act, either by reducing the noise or by requiring hearing protection.

The Action Level (AL) is 85 dBA as an eight-hour time-weighted average. It is lower than the PEL and triggers the full hearing conservation program described below.²

The standard uses a 5 dB exchange rate. Every 5 dBA increase over 90 cuts the allowable exposure time in half: 95 dBA for four hours, 100 dBA for two hours, 105 dBA for one hour, 110 dBA for 30 minutes, and 115 dBA for 15 minutes or less. When a shift includes noise at different levels, each period’s fraction of its allowed time gets added together; a combined total above 1.0 violates the standard.²

Impact or impulsive noise, such as a punch press or a gunshot, cannot exceed 140 dB peak sound pressure level at any moment, regardless of how brief the exposure is.²

When Employers Must Monitor Noise

An employer has to set up monitoring whenever there is reason to believe any worker’s exposure could reach 85 dBA. That reason can come from employee complaints, from manufacturer data on the equipment, or simply from the type of machinery in the space. Measurements have to capture all continuous, intermittent, and impulsive noise between 80 dBA and 130 dBA.¹

Two instruments do the work. Sound level meters take spot readings at a location. Dosimeters clip to a worker and record personal exposure across the whole shift. Whichever the employer uses, it has to be calibrated before each measurement.¹

Every worker whose exposure meets or exceeds the Action Level has to be notified of the results. That notice is not optional and cannot wait for the next safety meeting.¹

What the Hearing Conservation Program Requires

Once monitoring confirms any employee at or above 85 dBA TWA, the employer must run a continuing hearing conservation program. It has four moving parts: audiometric testing, hearing protection, annual training, and recordkeeping.¹

Baseline and Annual Hearing Tests

Each covered worker gets a baseline audiogram within six months of first being exposed at or above the Action Level. Employers using a mobile testing van instead of a fixed facility have up to one year, but the worker has to wear hearing protectors from the six-month point until the test happens.¹

Before the baseline, the worker needs at least 14 hours away from workplace noise. Wearing hearing protection during a shift can substitute for that quiet period.²

After the baseline, an annual audiogram follows. A licensed or certified audiologist, an otolaryngologist, another physician, or a properly trained technician performs the test; a technician has to work under the supervision of one of those professionals. The supervising professional reviews problem audiograms and decides whether further evaluation is warranted.²

Standard Threshold Shifts

A Standard Threshold Shift (STS) is an average hearing loss of 10 dB or more at 2,000, 3,000, and 4,000 Hz in either ear compared to the baseline. When the annual test shows an STS, the employer may retest within 30 days and use that retest as the official annual result. If the shift is confirmed, the employer must notify the worker in writing within 21 days.²

Unless a physician finds the shift unrelated to workplace noise, the employer then has to take action. A worker not yet in protectors has to be fitted, trained, and required to wear them. A worker already using protectors has to be refitted, retrained, and given protectors with greater noise reduction if the current pair is not enough. The employer also has to refer the worker for further clinical evaluation when additional testing or a medical opinion is needed.²

Annual Training

Every worker in the program has to be trained each year on how noise damages hearing, how to use hearing protectors, and why audiometric testing matters. Training has to be updated when equipment, processes, or protector types change.¹

Records

Noise exposure measurements have to be kept for at least two years. Audiometric test records have to be kept for the whole duration of the affected worker’s employment.¹

When Workers Must Actually Wear Hearing Protection

Availability and mandatory use are two different obligations, and this is where employers most often go wrong.

At 85 dBA TWA, the employer has to make hearing protectors available at no cost to every exposed worker, offer a variety of styles, and ensure proper fitting. Wearing them is only mandatory in three situations: when exposure exceeds the PEL and controls cannot bring it down; when a worker exposed at 85 dBA or above has not yet had a baseline audiogram; and when a worker has experienced a standard threshold shift.²

Protectors also have to attenuate enough for the specific environment. For most workers, they must bring exposure down to at least 90 dBA TWA. For a worker who has experienced an STS, they must bring exposure down to 85 dBA TWA or lower.¹

The manufacturer’s Noise Reduction Rating (NRR) is used to check whether a protector is strong enough. When noise measurements were taken with an A-weighted meter (the most common approach), you subtract 7 dB from the NRR, then subtract that remainder from the measured noise level. A protector rated NRR 29 used in a 100 dBA environment: 29 minus 7 is 22, and 100 minus 22 gives an estimated exposure of 78 dBA under the protector.¹

NIOSH recommends wearing both earplugs and earmuffs when exposure exceeds 100 dBA TWA. OSHA’s simplified method for dual protection adds 5 dBA to the NRR of whichever device rates higher.

Engineering and Administrative Controls Come First

Hearing protectors are not an acceptable substitute for controlling the noise itself when controls are feasible. When exposure exceeds the Table G-16 limits, the employer’s first duty is to bring the noise down through engineering or administrative controls.¹

Engineering controls target the noise at its source or along its path: sound enclosures around machinery, vibration dampening mounts, barriers, or swapping a loud component for a quieter one. Administrative controls change how workers interact with the noise: rotating people between noisy and quiet tasks, scheduling loud operations when fewer workers are present, or limiting time in high-noise areas.

Protectors as the primary control are only acceptable when engineering and administrative options have been considered and determined not to be feasible. Feasibility asks whether a control is effective, recognized in the industry, readily available, and cost-effective across the short and long term. Simply handing out earplugs without investigating quieter equipment or enclosures does not meet the standard.²

Your Right to See Your Records

Workers and their designated representatives can request copies of noise exposure and audiometric records under 29 CFR 1910.1020. The employer has to provide access within a reasonable time, and in no case later than 15 working days after the request. Copies are free to the employee. A union representative acting as a designated representative can reach exposure records without individual written consent from each worker; medical records, including audiograms, still require the specific written consent of the worker involved.³

How the Rules Differ for Construction

Everything above sits under 29 CFR 1910.95, the general industry rule. Construction work is governed by a separate and much less detailed standard, 29 CFR 1926.52. The permissible exposure limits in the Table D-2 duration chart match general industry’s Table G-16, and the 140 dB peak limit for impact noise still applies.⁴

The big difference is what happens below the PEL. In construction, the hearing conservation program is only required when noise exceeds the PEL, not at the 85 dBA Action Level that triggers coverage in general industry. Construction also lacks the general industry standard’s detailed rules on baseline audiograms, annual testing, training, and protector evaluation.⁴

Penalties Employers Face

OSHA adjusts its maximum penalty amounts each year for inflation. Under the adjustment effective January 15, 2025, the ceilings are:⁵

Serious violation: up to $16,550 per violation
Other-than-serious violation: up to $16,550 per violation
Willful or repeated violation: up to $165,514 per violation
Failure to abate: up to $16,550 per day beyond the abatement deadline

A noise citation can stack. An employer with inadequate monitoring, no hearing conservation program, missing audiometric testing, and no training can face separate violations for each gap. Willful violations, where the employer knew about the standard and ignored it, carry penalties roughly ten times higher than serious violations. Failure-to-abate penalties accumulate daily, so ignoring a citation past its correction deadline can outrun the original fine within weeks.⁶

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eCFR. 29 CFR 1910.95 – Occupational Noise Exposure
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Occupational Safety and Health Administration. 1910.95 – Occupational Noise Exposure
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Occupational Safety and Health Administration. Access to Employee Exposure and Medical Records
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Occupational Safety and Health Administration. 1926.52 – Occupational Noise Exposure
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Occupational Safety and Health Administration. OSHA Penalties
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Occupational Safety and Health Administration. 2025 Annual Adjustments to OSHA Civil Penalties