Occupational noise exposure

Protection is required when workplace sound levels exceed the limits shown in Table G-16 measured on the A scale of a sound level meter at slow response. See 1910.95(a) for the requirement and Table G-16 for the specific dBA/time combinations employers must meet.

If noise variations produce maxima at intervals of 1 second or less, the noise is considered continuous for measurement and compliance purposes. This rule is in 1910.95(b)(2).

You must use the summation rule: add the fractions C1/T1 + C2/T2 + ... + Cn/Tn, where Cn is the actual time at a given noise level and Tn is the permitted time at that level from Table G-16; if the sum exceeds 1, the mixed exposure exceeds the limit. This procedure is described in 1910.95(b)(2) and Table G-16.

An employer must establish a hearing conservation program whenever employee exposures equal or exceed an 8-hour TWA of 85 dBA (the action level). See 1910.95(c)(1) and (c)(2) for the definition of the action level and program requirements.

No. For determining who must be included in the hearing conservation program, employers must compute employee exposures without regard to any attenuation provided by hearing protectors. See 1910.95(c)(1) and 1910.95(c)(2).

Employers must use representative personal sampling when circumstances like high worker mobility, big variations in sound levels, or a large impulse-noise component make area monitoring inappropriate—unless the employer can show area sampling gives equivalent results. See 1910.95(d)(1)(ii).

Instruments must integrate all continuous, intermittent, and impulsive sound levels from 80 dB to 130 dB when measuring employee noise exposure. See 1910.95(d)(2)(i).

Instruments used to measure employee noise exposure must be calibrated to ensure measurement accuracy. See 1910.95(d)(2)(ii).

Monitoring must be repeated whenever a change in production, process, equipment, or controls increases exposures so that additional employees may reach the action level or existing hearing protector attenuation may become inadequate under paragraph (j). See 1910.95(d)(3) and (d)(3)(i)-(ii).

Employers must notify each employee exposed at or above an 8-hour TWA of 85 dBA of the monitoring results. See the notification requirement in 1910.95(e).

Yes. Employers must provide affected employees or their representatives the opportunity to observe any noise measurements conducted under this standard. See 1910.95(f).

Octave band sound pressure levels may be converted to an equivalent A-weighted sound level by plotting them on the Figure G-9 contours and reading the A-weighted level at the point of highest penetration; that equivalent level is used with Table G-16. See 1910.95(b)(1) and the Figure G-9 guidance.

Impulsive or impact noise exposure should not exceed 140 dB peak sound pressure level. This limit is stated in 1910.95(b)(2).

Employers must make audiometric testing available to all employees whose exposures equal or exceed an 8-hour TWA of 85 dBA, and the program must be provided at no cost to employees. See 1910.95(g)(1) and 1910.95(g)(2).

Audiometric tests may be performed by a licensed/certified audiologist, an otolaryngologist, a physician, or a certified or otherwise qualified technician responsible to an audiologist or physician; all audiograms must meet the requirements in appendix C. See 1910.95(g)(3) and 1910.95(g)(4).

A valid baseline audiogram must be established within 6 months of an employee's first exposure at or above the action level (or within 1 year when using mobile test vans), and baseline testing must be preceded by at least 14 hours without workplace noise exposure unless hearing protectors are used as a substitute. See 1910.95(g)(5)(i)-(iii).

Employers must obtain an annual audiogram for each employee exposed at or above an 8-hour TWA of 85 dBA; if the annual audiogram indicates a standard threshold shift, the employer may obtain a retest within 30 days and must have the audiologist or physician review problem audiograms and determine any needed follow-up. See 1910.95(g)(6) and 1910.95(g)(7).

When a STS is work related or aggravated by occupational noise, the employer must inform the employee in writing within 21 days and ensure: employees not using protectors are fitted, trained and required to use them; employees already using protectors are refitted, retrained, and provided with higher-attenuation protectors if necessary; and the employee is referred for clinical evaluation if needed. See 1910.95(g)(7)(iii) and 1910.95(g)(8)(ii).

If subsequent audiometric testing shows a STS is not persistent for an employee whose exposure is less than an 8-hour TWA of 90 dBA, the employer shall inform the employee of the new interpretation and may discontinue the required use of hearing protectors for that employee. See 1910.95(g)(8)(iii).

Employers must provide the evaluator: a copy of the hearing conservation requirements in paragraphs (c)–(n); the employee's baseline and most recent audiogram; measurements of background sound pressure levels in the audiometric test room per appendix D; and records of audiometer calibrations required by paragraph (h)(5). See 1910.95(g)(7)(iii)(A)-(D).

Employers must keep records of audiometer calibrations as required by paragraph (h)(5) and provide those records to the person evaluating problem audiograms; those records are part of the audiometric program records specified in the standard. See 1910.95(h)(5) and 1910.95(g)(7)(iii)(D).

The sampling strategy must identify employees for inclusion in the hearing conservation program and support proper selection of hearing protectors; it should integrate all relevant sound levels (continuous, intermittent, impulsive from 80–130 dB) and use representative personal sampling where area sampling would be inappropriate. See 1910.95(d)(1)(i) and 1910.95(d)(2)(i).

Employers must provide hearing protectors at no cost to employees when an employee's 8-hour time-weighted average noise exposure is 85 dBA or greater. This is required by 1910.95(i)(1).

• Provide replacements as needed. See the same paragraph for the replacement requirement.
• This requirement applies even if other controls are being used; hearing protectors supplement engineering and administrative controls where required.

An employer must ensure hearing protectors are worn by employees who are required to use personal protective equipment under 1910.95(i)(2)(i) and by any employee exposed to an 8‑hour time-weighted average of 85 dBA or greater in the situations listed in 1910.95(i)(2)(ii).

• Specifically, employees must wear protectors if they haven’t had a baseline audiogram yet or if they have experienced a standard threshold shift, per 1910.95(i)(2)(ii)(A)-(B).
• Employers must supervise use and ensure proper initial fitting (1910.95(i)(5)).

Yes. Employees exposed to an 8‑hour TWA of 85 dBA or greater must wear hearing protectors if they have not yet had a baseline audiogram established or if they have experienced a standard threshold shift, as required by 1910.95(i)(2)(ii).

• This ensures protection during the period before the baseline is documented and after any measured hearing loss (standard threshold shift).

Hearing protectors must reduce an employee’s 8‑hour time-weighted average exposure to at least 90 dBA for general use and to 85 dBA or below for employees who have experienced a standard threshold shift, per 1910.95(j)(2) and 1910.95(j)(3).

• Evaluate attenuation using one of the methods in 1910.95(j)(1) (appendix B).
• Re-evaluate when workplace noise increases (1910.95(j)(4)).

The employer must evaluate hearing protector attenuation for the specific noise environment using one of the evaluation methods described in appendix B, as required by 1910.95(j)(1).

• Appendix B methods include using labeled attenuation values, derating methods, or fit‑testing approaches described there.
• Document the method and results so you can show the selected protectors provide required attenuation to the appropriate TWA (1910.95(j)(2)-(3)).

Employers must train every employee who is exposed to noise at or above an 8‑hour TWA of 85 dBA, and training must cover the effects of noise on hearing, the purpose and use of hearing protectors (including selection, fitting, use and care), and the purpose and procedures of audiometric testing, as specified in 1910.95(k) and 1910.95(k)(3).

• Employers must ensure employee participation and keep training updated to reflect changes in equipment or processes (1910.95(k)(2)).

Training must be repeated annually for each employee included in the hearing conservation program, according to 1910.95(k)(2).

• Update information when protective equipment or work processes change to keep the training current.

Audiometric tests must be pure‑tone, air‑conduction hearing threshold exams at a minimum of 500, 1000, 2000, 3000, 4000, and 6000 Hz for each ear, and audiometers must meet the American National Standard Specification for Audiometers S3.6‑1969, as required by 1910.95(h)(1) and 1910.95(h)(2).

• Tests at each frequency are taken separately for each ear.
• Use audiometers maintained and used in accordance with S3.6‑1969 (1910.95(h)(2)).

You must perform a daily functional check of the audiometer, an acoustic calibration at least annually, and an exhaustive calibration at least every two years, as required by 1910.95(h)(5)(i), 1910.95(h)(5)(ii), and 1910.95(h)(5)(iii).

• Daily: check operation with a person of known stable thresholds and listen for distorted sounds; deviations >=10 dB require acoustic calibration (1910.95(h)(5)(i)).
• Annual acoustic check: follow appendix E; deviations >=15 dB require an exhaustive calibration (1910.95(h)(5)(ii)).
• Biennial exhaustive calibration: follow the S3.6‑1969 sections noted in 1910.95(h)(5)(iii).

An annual audiogram may be substituted for the baseline audiogram when the evaluating audiologist, otolaryngologist, or physician judges that the standard threshold shift is persistent or that the annual audiogram shows significant improvement over the baseline, per 1910.95(g)(9)(i)-(ii).

A standard threshold shift (STS) is an average change in hearing threshold of 10 dB or more at 2000, 3000, and 4000 Hz in either ear, as defined in 1910.95(g)(10)(i).

• Employers must allow for age correction per 1910.95(g)(10)(ii) when determining STS.

Yes. Employers may correct the annual audiogram for the contribution of aging (presbycusis) using the age‑correction procedure described in appendix F, as allowed by 1910.95(g)(10)(ii).

• Use appendix F: Calculation and Application of Age Correction to Audiograms to apply the correction properly.

Each audiometric test record must include the employee’s name and job classification, date of the audiogram, the examiner’s name, the date of the last acoustic or exhaustive calibration of the audiometer, and the employee’s most recent noise exposure assessment, as listed in 1910.95(m)(2)(ii).

• The employer must also maintain records of audiometric test room background sound pressure levels per 1910.95(m)(2)(ii)(F).

Noise exposure measurement records must be kept for two years, and audiometric test records must be retained for the duration of the affected employee’s employment, as specified in 1910.95(m)(3)(i)-(ii).

• Keep noise-exposure records at least two years to meet the standard’s minimum retention requirement.

Employees, former employees, representatives designated by the employee, and the Assistant Secretary must be given access to records required by this section, and access is governed by the provisions of 1910.1020(a)-(e) and 1910.1020(g)-(i), as stated in 1910.95(m)(4).

• Employers must follow the record access, confidentiality, and disclosure rules in 1910.1020 when providing these records.

The employer must re-evaluate hearing protector attenuation whenever employee noise exposures increase so that the protectors may no longer provide adequate attenuation, and provide more effective protectors when necessary, as required by 1910.95(j)(4).

• Re-evaluation should be done promptly after any process, equipment, or operational change that raises employee noise exposure.

Employers must give employees the opportunity to select hearing protectors from a variety of suitable types provided by the employer, provide training on use and care, ensure proper initial fitting, and supervise correct use, per 1910.95(i)(3), 1910.95(i)(4), and 1910.95(i)(5).

• Keep records of training and supervise use to ensure protection is effective in practice.

The employer must make a copy of the standard available to affected employees or their representatives and post a copy in the workplace, provide informational materials supplied by the Assistant Secretary, and, upon request, provide training materials to the Assistant Secretary and the Director, as required by 1910.95(l)(1)-(3).

• Make sure employees know where to find the standard and training materials and provide copies on request.

Appendices A, B, C, D, and E are incorporated as mandatory parts of the standard, while appendices F and G are informational only, as stated in 1910.95(n)(1)-(2).

• Use mandatory appendices (for example, Appendix B for attenuation evaluation and Appendix D for test rooms) to comply with the standard.

Yes. Paragraphs (c) through (n) of the noise standard do not apply to employers engaged in oil and gas well drilling and servicing operations, per 1910.95(o).

• Other provisions of the standard (outside (c)–(n)) still apply as applicable.

If the employer ceases to do business, they must transfer all records required by the noise standard to the successor employer, who must then retain them for the remainder of the prescribed retention period in [1910.95(m)(3)], as required by 1910.95(m)(5).

• This ensures continuity of medical and exposure records for affected employees.