OSHA 29 CFR 1910.95

OSHA 29 CFR 1910.95 is the federal regulation governing occupational noise exposure in general industry. It sets a permissible exposure limit (PEL) of 90 dBA as an 8-hour time-weighted average (TWA), an action level of 85 dBA TWA that triggers a full Hearing Conservation Program, and detailed requirements for noise monitoring, audiometric testing, hearing protection, training, and recordkeeping. Hearing loss caused by workplace noise is permanent and cumulative, and it is one of the most common occupational illnesses recorded on OSHA 300 logs.

The standard applies to every general industry employer where employees are exposed to noise at or above the action level. Construction has its own noise rules under 29 CFR 1926.52 and 1926.101, which are less prescriptive (no federally mandated audiometric testing) but still require feasible engineering and administrative controls plus hearing protection.

The standard runs from paragraph (a) through (m) plus several appendices. The most frequently cited provisions are summarized below.

OSHA 1910.95 also includes mandatory appendices A (5 dB exchange rate calculation), B (methods for estimating attenuation), C (audiometric measuring instruments), D (audiometric test rooms), E (acoustic calibration), and F (calculations and application of age corrections).

OSHA uses a 5 dB exchange rate, meaning the allowable exposure time is cut in half for every 5 dB increase in sound level above 90 dBA. NIOSH and most of the rest of the world use a 3 dB exchange rate (which is more health-protective), but OSHA enforcement still relies on the 5 dB rule from Table G-16.

Table G-16: Permissible noise exposures

PEL vs Action Level: what triggers what

Once any employee's 8-hour TWA reaches 85 dBA, paragraph (c) requires the employer to administer a continuing, effective Hearing Conservation Program (HCP). The HCP has six interlocking elements, and OSHA inspectors will ask for documentation of each one.

• Noise exposure monitoring — Identify employees at or above the action level using personal dosimetry or area sampling representative of actual exposure.
• Audiometric testing — Baseline within 6 months (preceded by at least 14 hours away from workplace noise), then annual audiograms by a licensed or certified professional.
• Hearing protection — Variety of HPDs offered at no cost, employee choice from the available selection, attenuation adequate for the exposure.
• Employee training — Annual instruction on noise effects, purpose of audiograms, and proper selection/fit/use/care of HPDs.
• Notification and access — Employees must be notified of monitoring results and given access to the standard, their records, and relevant materials.
• Recordkeeping — Noise exposure data retained 2 years; audiometric records retained for the duration of employment.

Monitoring is the foundation of the program. Without reliable exposure data, you can't determine who is in the HCP, what hearing protection is adequate, or whether engineering controls are working.

When to monitor

• Whenever sound levels are likely to expose any employee at or above 85 dBA TWA
• After any change in production, process, equipment, or controls that could increase exposure
• When new equipment is introduced or existing equipment moved to a new area
• When existing controls (enclosures, mufflers, isolation pads) degrade

Two acceptable methods

Instruments must include all continuous, intermittent, and impulsive sound levels from 80 to 130 dBA in the average. Calibrate before and after each use per the manufacturer's instructions and Appendix E.

Employee notification and observation

Paragraph (e) requires the employer to notify each monitored employee of the results. Paragraph (f) gives employees and their representatives the right to observe noise monitoring being conducted on their behalf.

Audiometric testing is how the HCP detects hearing loss before it becomes severe enough to be noticed by the employee. The program revolves around comparing each annual audiogram against the employee's baseline.

Baseline and annual audiograms

• Baseline within 6 months of an employee's first exposure at or above the action level (or 1 year if a mobile test van is used; HPDs must be worn in the interim)
• Employees should avoid workplace noise for at least 14 hours before the baseline audiogram (HPDs may be substituted)
• Annual audiogram thereafter; compare to baseline to evaluate Standard Threshold Shifts
• Tested at 500, 1000, 2000, 3000, 4000, and 6000 Hz, each ear separately
• Conducted by a licensed/certified audiologist, otolaryngologist, other qualified physician, or technician certified by the Council of Accreditation in Occupational Hearing Conservation (CAOHC)

Standard Threshold Shift (STS)

A Standard Threshold Shift is defined as a change in hearing threshold, relative to the baseline audiogram, of an average of 10 dB or more at 2000, 3000, and 4000 Hz in either ear. Age corrections per Appendix F may be applied.

When an STS is identified, the employer must, within 21 days:

• Notify the employee in writing
• Refit and retrain the employee in hearing protector use, or provide more protective HPDs if already in the program
• Require HPD use for affected employees not previously required to wear them
• Refer the employee for a clinical audiological evaluation if necessary

A confirmed STS that meets the OSHA recordable hearing-loss criteria (a 25-dB or greater hearing level above audiometric zero, averaged at 2000, 3000, and 4000 Hz, in the same ear as the STS) must be entered on the OSHA 300 log.

Sections (i) and (j) require employers to make hearing protectors available at no cost to all employees exposed at or above the action level, give employees a choice from a variety of suitable HPDs, and ensure attenuation is adequate for the exposure.

Common HPD types

Noise Reduction Rating (NRR) and OSHA derating

The NRR printed on every HPD package is set under EPA regulations (40 CFR Part 211) using a laboratory test method (ANSI S3.19-1974). Real-world attenuation is almost always lower than the labeled NRR because of imperfect fit, partial wear time, and product variability.

OSHA's Technical Manual recommends derating the NRR before comparing it to the workplace TWA. Two common formulas:

HPDs and other PPE

Hearing protection rarely sits alone. Many employees wear earmuffs in combination with ANSI Z89.1 hard hats using cap-mounted earmuff brackets, or with safety glasses whose temples can break the muff seal. Confirm the muff is rated for hard-hat mounting and re-verify NRR if the manufacturer publishes a separate cap-mount value.

For employees in respiratory protection programs, communication and warning audibility through HPDs becomes more difficult. Coordinate hearing conservation with OSHA 1910.134 respiratory protection when both apply.

Every employee in the Hearing Conservation Program must receive training at least annually. The employer must ensure the training material is updated to reflect changes in protective equipment and work processes.

The training program must cover, at a minimum:

• The effects of noise on hearing
• The purpose, advantages, disadvantages, and attenuation of various types of hearing protectors
• Instructions on selection, fitting, use, and care of hearing protectors
• The purpose of audiometric testing and an explanation of the test procedure

Employees must also have access to a copy of the standard, posted in the workplace or otherwise readily available, and to all informational materials provided by OSHA.

OSHA 1910.95 covers general industry. Construction has its own noise requirements that are similar in numeric limits but materially less prescriptive in program structure.

Multi-employer construction sites still need to consider noise from adjacent trades. A roofing crew and a demolition crew working in the same area can push exposures above the PEL even if neither activity does so on its own.

OSHA 1910.95(m) sets explicit retention periods, but most successful programs maintain a broader documentation set to support inspections and workers' compensation defense.

• Noise exposure measurements: Retain at least 2 years
• Audiometric test records: Retain for the duration of the affected employee's employment (and per state workers' comp rules)
• Audiometer calibration records: Functional check daily; acoustic calibration annually; exhaustive calibration every 2 years
• HPD selection logs: Which HPDs were offered, which the employee chose, fit-test or initial training date
• Training rosters: Annual training attendance with topics covered and signature
• Written HCP: Not required by the standard but expected by most inspectors as evidence of program management
• OSHA 300 entries: Recordable hearing loss cases (work relationship, STS confirmation, 25 dB hearing level threshold)

1910.95 is consistently in OSHA's top 25 most-cited general industry standards. Citations almost always cluster around a few common gaps:

Penalty maximums adjust each January for inflation. The 2024 figures above illustrate the order of magnitude. Recordable hearing loss cases also count against the employer's DART rate and can trigger Severe Violator Enforcement Program scrutiny on subsequent inspections.

OSHA references

• 29 CFR 1910.95 Full Regulation Text
• OSHA Occupational Noise Exposure Topic Page
• OSHA 3074: Hearing Conservation (PDF)
• 29 CFR 1926.52: Construction Noise Exposure
• NIOSH Occupational Noise & Hearing Loss

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