A hearing conservation program is the set of measures that the US federal OSHA noise standard, 29 CFR 1910.95, requires in general industry whenever a worker’s noise exposure equals or exceeds an 8-hour time-weighted average (TWA) of 85 decibels on the A scale, or a dose of 50 percent. It combines noise monitoring, audiometric testing, hearing protectors, training and recordkeeping (§1910.95(d) to (m)).
Across many sites, with workers who transfer, rotate, return to noisy jobs or arrive through contractors, the hard part is keeping each worker’s baseline and annual test on track. This guide covers what 1910.95 requires, how a hearing shift reaches the OSHA 300 Log, how to run the program across sites, and where construction, mining, Great Britain and the EU differ.
When OSHA requires a hearing conservation program
Employers must run a continuing, effective hearing conservation program whenever exposures equal or exceed an 8-hour TWA of 85 dBA, measured at slow response, or a dose of 50 percent, computed without regard to any attenuation from hearing protectors (§1910.95(c)(1)). That level is called the action level (§1910.95(c)(2)).
The permissible exposure limit is separate: Table G-16 allows 90 dBA for 8 hours, and above it feasible administrative or engineering controls come first, then personal protective equipment (§1910.95(a), (b)(1)).
Two scope points matter for high-risk industries:
- Oil and gas well drilling and servicing. Paragraphs (c) to (n), the hearing conservation program itself, do not apply to employers engaged in oil and gas well drilling and servicing operations (§1910.95(o)). The exemption does not reach paragraphs (a) and (b), the exposure limits and controls.
- State Plans. States that run their own OSHA-approved programs must have standards at least as effective as federal OSHA’s, and may have different or additional requirements (OSHA Bulletin 9).
The parts of the program at a glance
| Element | What 1910.95 requires | Paragraph |
|---|---|---|
| Monitoring | A monitoring program when exposure may reach 85 dBA TWA; repeat it after changes that raise exposure | (d) |
| Notification | Tell each worker exposed at or above 85 dBA TWA the monitoring results; let workers or their representatives observe measurements | (e), (f) |
| Audiometric testing | Baseline within 6 months of first exposure at the action level (1 year with mobile test vans), then at least annually | (g) |
| Hearing protectors | Available at no cost to everyone at or above 85 dBA TWA, with a choice of suitable types and attenuation evaluated for the noise | (i), (j) |
| Training | Each exposed worker, repeated annually | (k) |
| Information | Copies of the standard made available and a copy posted in the workplace | (l) |
| Records | Exposure measurements and audiometric test records, kept for set periods and open to workers | (m) |
Noise monitoring
When information indicates that any worker’s exposure may equal or exceed 85 dBA TWA, the employer must develop and implement a monitoring program (§1910.95(d)(1)). The sampling strategy has two jobs: identify who belongs in the hearing conservation program, and support the right choice of hearing protectors (§1910.95(d)(1)(i)).
- Mobile workers. Where high worker mobility, large variations in sound level or significant impulse noise make area monitoring generally inappropriate, the employer must use representative personal sampling, unless it can show area sampling gives equivalent results (§1910.95(d)(1)(ii)).
- Repeat. Monitoring is repeated when a change in production, process, equipment or controls increases exposure enough to bring more workers to the action level or make hearing protectors inadequate (§1910.95(d)(3)).
Audiometric testing: baseline and annual audiograms
Audiometric testing must be made available to every worker exposed at or above 85 dBA TWA, at no cost to them (§1910.95(g)(1), (g)(2)). Tests are performed by a licensed or certified audiologist, otolaryngologist or other physician, or by a qualified technician who must be responsible to one of them (§1910.95(g)(3)). Audiometric testing is a requirement of the noise standard itself. OSHA’s page of standards that address medical screening and medical surveillance, which includes lead, does not list 1910.95.
The baseline audiogram is the reference for every later test:
- Deadline. Within 6 months of a worker’s first exposure at or above the action level (§1910.95(g)(5)(i)).
- Mobile test vans. Where vans are used, within 1 year, and workers must wear hearing protectors for any period beyond 6 months after first exposure until the baseline is obtained (§1910.95(g)(5)(ii)).
- Quiet period. At least 14 hours without workplace noise before the baseline test, for which hearing protectors may substitute; workers must also be told to avoid high non-occupational noise in that period (§1910.95(g)(5)(iii), (iv)).
After the baseline, a new audiogram is required at least annually for each worker exposed at or above 85 dBA TWA (§1910.95(g)(6)). Each ear is tested separately at a minimum of 500, 1,000, 2,000, 3,000, 4,000 and 6,000 Hz (§1910.95(h)(1)).
After a standard threshold shift
Each annual audiogram is compared with the worker’s baseline to decide whether it is valid and whether a standard threshold shift (STS) has occurred, and a technician may make the comparison (§1910.95(g)(7)(i)). If it shows an STS, the employer may obtain a retest within 30 days and treat it as the annual audiogram (§1910.95(g)(7)(ii)). An audiologist, otolaryngologist or physician reviews problem audiograms and decides whether further evaluation is needed (§1910.95(g)(7)(iii)).
When an STS is found, three duties follow:
- Written notice. The worker must be told in writing within 21 days of the determination (§1910.95(g)(8)(i)).
- Protection and referral. Unless a physician determines the STS is not work related or aggravated by occupational noise, the employer fits or refits hearing protectors, trains or retrains the worker, and arranges referral for clinical audiological or otological evaluation in the cases the standard lists (§1910.95(g)(8)(ii)). Protectors must then bring that worker’s exposure to 85 dBA TWA or below (§1910.95(j)(3)).
- OSHA 300 Log. An employer covered by OSHA’s recordkeeping rule must record a work-related STS when the worker’s total hearing level is also 25 dB or more above audiometric zero, averaged at 2,000, 3,000 and 4,000 Hz, in the same ear or ears (§1904.10(a)). If a retest within 30 days does not confirm it, the case need not be recorded; if it does, it goes on the OSHA 300 Log within seven calendar days of the retest (§1904.10(b)(4)), in the hearing loss column (§1904.10(b)(7)). The full criteria are in 1904.10.
Once a worker has had a recordable hearing loss, later audiograms are compared with the revised baseline that reflects it (§1904.10(b)(2)(i)). Under 1910.95, an annual audiogram may replace the baseline when the evaluating audiologist, otolaryngologist or physician judges a shift persistent, or hearing significantly improved (§1910.95(g)(9)).
Training, information and records
Each worker exposed at or above 85 dBA TWA must be trained, every year, on the effects of noise, hearing protectors and the purpose of audiometric testing (§1910.95(k)). A copy of the standard must be available to affected workers and posted in the workplace (§1910.95(l)(1)).
The recordkeeping paragraph sets what to keep and for how long (§1910.95(m)):
| Record | Contents | Minimum retention |
|---|---|---|
| Noise exposure measurements | All measurements required by the monitoring paragraph | 2 years |
| Audiometric test records | Worker’s name and job classification, date of the audiogram, examiner’s name, date of the last acoustic or exhaustive audiometer calibration, the worker’s most recent noise exposure assessment | Duration of the worker’s employment |
Records of background sound levels in test rooms are kept too (§1910.95(m)(2)(ii)(F)). All records must be provided on request to workers, former workers, their designated representatives and OSHA, under the access provisions of 29 CFR 1910.1020 that the standard applies (§1910.95(m)(4)), the same rules that govern the employee medical record. See our guides to OSHA employee medical records and how long to keep occupational health records. If the employer ceases to do business, it transfers the records to the successor employer, which keeps them for the rest of the period (§1910.95(m)(5)).
Running a hearing conservation program across many sites
Multi-site operators meet four practical problems. Two come straight from regulatory deadlines in 1910.95 and, for recording, 1904.10. OSHA has addressed the other two in interpretation letters, which explain how OSHA reads a standard but cannot create new obligations, and, for temporary workers, in a guidance bulletin.
Keep annual tests due per worker, not per site
The annual audiogram is due at least annually after the baseline audiogram, for each exposed worker (§1910.95(g)(6)), and each baseline is due within 6 months of that worker’s own first exposure at the action level, or 1 year with mobile test vans (§1910.95(g)(5)). With people joining, transferring and returning at different dates, a due date for each worker, and for each new starter’s baseline, keeps the calendar visible.
Keep the original baseline when workers move
In OSHA’s view, an employer cannot set new baselines for workers who left a hearing conservation area and later return. Because audiometric records are kept for the duration of employment, the employer still has the original baseline, and later audiograms are compared with it, or with the last revised baseline after an STS (OSHA letter, January 31, 2011). After a change of ownership, OSHA has said the successor would normally keep using the former employer’s baselines and their annual schedule, unless there is a good-faith, reasonable basis to doubt their validity (OSHA letter, April 27, 2004). In both cases the retention and transfer rules (§1910.95(m)(3)(ii), (m)(5)) keep the earlier baseline, original or revised, on file for that comparison.
Decide who tests contractors and temporary workers
OSHA says a staffing agency and its client are typically joint employers of temporary workers. The host usually has primary responsibility for monitoring, controls, hearing protection and the hearing conservation program, while the agency must learn the site’s noise hazards before placing anyone. Where workers move between hosts for less than a year and could be missed by each host’s testing, the agency may be better placed to provide baseline and annual audiograms. The employers should establish who handles each part of the program before work begins and consider confirming it in writing, and neither can avoid its responsibilities by requiring the other to perform them (OSHA Bulletin 9).
The noise standard has no specific exemption for temporary or seasonal workers. OSHA has said no baseline is required if testing would fall due after the worker’s term ends, but a worker employed by the same employer in two or more periods within 12 months, exposed at the action level each time, must be offered audiograms. The same letter points out that, where a baseline is delayed beyond six months under the mobile test van exception, §1910.95(i)(2)(ii)(A), read with (g)(5)(ii), requires hearing protectors for any worker exposed at or above the action level until the baseline is obtained, temporary and seasonal workers included (OSHA letter, September 4, 2019). Our post on contractor health records covers who keeps those files.
Track STS deadlines centrally
The 21-day written notice, the optional 30-day retest and the seven-day recording window each start at a different event. When audiograms are read off-site, a central log of each shift, its dates and its follow-up keeps the evidence in one place.
In MyC’s health surveillance software, surveillance is scheduled per worker from their exposure group, with due dates and expiry alerts. Results from connected audiometers land in the worker’s record and can be compared with their own baseline and with reference standards such as OSHA. Employees and contractors keep the same health record across sites and rotations, so their health surveillance history follows them between sites on the MyC platform.
Construction and mining follow different rules
Construction. The construction noise standard, 29 CFR 1926.52, uses the same 90 dBA, 8-hour table, and requires a continuing, effective hearing conservation program wherever sound levels exceed it (§1926.52(d)(1)). It does not set the 85 dBA action level or the baseline and annual audiogram deadlines of 1910.95. Where noise cannot be reduced to the table’s levels, ear protective devices must be provided and used (29 CFR 1926.101).
Mining. MSHA’s noise standard, 30 CFR Part 62, covers surface and underground metal, nonmetal and coal mines subject to the Federal Mine Safety and Health Act of 1977 (§62.100). The action level is the same 85 dBA TWA and triggers enrollment in a hearing conservation program (§62.101, §62.120), but several details differ:
- The mine operator must offer miners the opportunity for audiometric testing (§62.170(a)), and MSHA’s summary table describes the testing as voluntary for miners exposed between the action level and the permissible level (§62.140).
- The baseline is due within 6 months of enrollment, or 12 months with mobile test vans, then tests at intervals of no more than 12 months (§62.170(a)(1), (b)).
- A change in enrollment status does not justify a new baseline, though one may be set for a miner away from the mine for more than 6 consecutive months (§62.170(a)(3)).
- Audiometric records are kept for the duration of employment plus at least 6 months (§62.171(c)).
- A reportable hearing loss, 25 dB or more worse than the baseline on average at 2,000, 3,000 and 4,000 Hz in either ear, is reported to MSHA unless a physician or audiologist finds it neither work related nor aggravated by occupational noise (§62.101, §62.175(b)).
- A successor mine operator must use the original operator’s baseline or revised baseline (§62.190(c)(2)).
The mining page shows how, in MyC, health surveillance history follows employees and contractors between mines.
Outside the US
Outside the US, other rules and thresholds apply. Two common references for multi-country operators:
Great Britain. The Control of Noise at Work Regulations 2005 set a lower exposure action value of 80 dB(A), an upper exposure action value of 85 dB(A) and an exposure limit value of 87 dB(A), as daily or weekly personal exposure (regulation 4). Where the risk assessment shows a risk to health, employees must be placed under suitable health surveillance that includes testing of their hearing, with a health record for each one (regulation 9). HSE guidance says hearing checks are for workers likely to be regularly exposed above the upper action values, or at risk for another reason, usually annually for the first two years of employment and then every three years.
European Union. Directive 2003/10/EC sets the same 80, 85 and 87 dB(A) values (Article 3). A worker exposed above the upper action value has the right to a hearing check by a doctor or another suitably qualified person under a doctor’s responsibility, and preventive audiometric testing must be available above the lower action value where the assessment indicates a risk. Each worker under surveillance has an individual health record (Article 10). The directive sets minimum requirements; member states write the detailed rules into national law.
For operators with sites in several of these jurisdictions, each site in MyC follows the company standard and is set up for its country’s requirements. The energy and manufacturing pages show health surveillance in those industries. To see it in practice, book a demo.
Questions
What noise level requires a hearing conservation program under OSHA?
In general industry, an 8-hour time-weighted average of 85 dBA or a dose of 50 percent, without counting hearing protector attenuation. Construction and mining use different rules.
How often is audiometric testing required?
A baseline within 6 months of first exposure at or above 85 dBA TWA (1 year with mobile test vans), then a new audiogram at least annually while the worker is exposed at that level.
How long must hearing test records be kept?
Under 1910.95, audiometric test records for the duration of the worker’s employment and noise exposure measurements for two years. Under MSHA’s Part 62, audiometric records for the duration of employment plus at least six months.
Can an employer take a new baseline when a worker transfers back into a noisy job?
OSHA has said no: later audiograms are compared with the original baseline, or with the last revised baseline after an STS.
Sources
- 29 CFR 1910.95: Occupational noise exposure (eCFR)
- 1910.95: Occupational noise exposure (OSHA)
- 1904.10: Recording criteria for cases involving occupational hearing loss (OSHA)
- 1910.1020: Access to employee exposure and medical records (OSHA)
- Medical screening and surveillance: standards (OSHA)
- OSHA interpretation, January 31, 2011: new baselines for employees returning to a hearing conservation program
- OSHA interpretation, April 27, 2004: retention of exposure and audiometric records by successor employers
- OSHA interpretation, September 4, 2019: the noise standard and audiometric testing of temporary employees
- OSHA Temporary Worker Initiative Bulletin 9: Noise exposure and hearing conservation
- 1926.52: Occupational noise exposure, construction (OSHA)
- 1926.101: Hearing protection, construction (OSHA)
- 30 CFR Part 62: Occupational noise exposure, MSHA (eCFR)
- Control of Noise at Work Regulations 2005, regulation 4: Exposure limit values and action values (legislation.gov.uk)
- Control of Noise at Work Regulations 2005, regulation 9: Health surveillance (legislation.gov.uk)
- Health surveillance for hearing (HSE)
- Directive 2003/10/EC on the exposure of workers to noise (EUR-Lex)
