What is the difference between the PEL and the action level for noise?

The PEL (90 dBA TWA) is the maximum legal exposure limit — exceeding it requires engineering or administrative controls before relying on hearing protection. The action level (85 dBA TWA) is the lower threshold that triggers a mandatory hearing conservation program in general industry: monitoring, annual audiometric testing, free hearing protection, and training. A worker between 85 and 90 dBA is not violating the PEL, but the employer must still implement the conservation program in general industry.

Does the construction noise standard require a hearing conservation program?

Yes — and the confusion is worth clearing up, because the two halves of this question have different answers. **The program itself is required**: 29 CFR 1926.52(d)(1) says that “in all cases where the sound levels exceed the values shown herein, a continuing, effective hearing conservation program shall be administered”. The trigger is Table D-2 — 90 dBA over 8 hours, sliding to 115 dBA at 15 minutes. **What is not codified for construction is the programme's CONTENT.** The 1983 Hearing Conservation Amendment — monitoring, baseline and annual audiograms, annual training, protector fitting, and the 85 dBA action level — was written into 1910.95(c)-(o) and never extended to construction. OSHA's 1992-08-04 interpretation letter names seven elements it expects and says a programme must incorporate as many as are feasible: a performance standard, not a checklist. State Plans may go further — Washington applies its full hearing-loss-prevention chapter to construction work (WAC 296-155-210), action level included.

When are engineering controls required instead of just providing earplugs?

Under 29 CFR 1910.95(b)(1), engineering or administrative controls are the primary required approach when noise levels exceed the PEL (90 dBA TWA). Hearing protection devices (earplugs, earmuffs) are the required supplement when controls are not feasible or cannot reduce exposure below the PEL. For workers exposed between 85–90 dBA under the action level, hearing protection devices are the primary protection — but the employer must also ensure they are worn correctly and are adequate for the noise level.

OSHA term · Glossary

Noise Exposure

Verified vs OSHA sources · 2026-10-05

OSHA's Permissible Exposure Limit (PEL) for occupational noise is 90 dBA as an 8-hour Time-Weighted Average (TWA) in both general industry (29 CFR 1910.95) and construction (29 CFR 1926.52). In general industry, an 85 dBA TWA action level triggers mandatory hearing conservation program requirements — monitoring, baseline and annual audiometric testing, hearing protection, and training. In construction, the 85 dBA action level is a NIOSH-recommended best practice, not a codified construction standard requirement. Both standards use a 5-dB exchange rate: for every 5 dB increase in noise level, the permissible exposure time is halved.

29 CFR 1910.9529 CFR 1926.5229 CFR 1910.95(a)

Also known as: occupational noise exposure, noise-induced hearing loss, NIHL, industrial noise

Noise Exposure at a glance

PEL: 90 dBA TWA (8-hr) — applies to both general industry (1910.95) and construction (1926.52).
Action level: 85 dBA TWA (8-hr) — triggers mandatory hearing conservation program in general industry (1910.95(c)); best practice in construction.
Exchange rate: 5 dB (OSHA) — PEL table: 90 dBA/8 hr; 95 dBA/4 hr; 100 dBA/2 hr; 105 dBA/1 hr; 110 dBA/30 min; 115 dBA/15 min.
NIOSH uses a stricter 3-dB exchange rate and an 85 dBA REL — more protective than OSHA's PEL.
Engineering and administrative controls must be implemented before relying on hearing protection devices (HPDs) as the primary protection.
Audiometric testing: baseline within 6 months of reaching the action level; annually thereafter.
A 10-dB Standard Threshold Shift (STS) triggers audiologist referral, rebaseline, and written notification to the employee.
Approximately 17% of all U.S. workers have some degree of occupational noise-induced hearing loss (NIOSH data).

In plain English

OSHA sets 90 dBA as the maximum allowable noise for an 8-hour shift. Above 85 dBA, general industry employers must enroll workers in a hearing conservation program with free annual hearing tests and hearing protection. Every 5 dB increase in noise level cuts the permissible exposure time in half — at 100 dBA, workers can only be exposed for 2 hours per shift.

What the rule says

“Protection against the effects of noise exposure shall be provided when the sound levels exceed those shown in Table G-16 when measured on the A scale of a standard sound level meter at slow response.”
29 CFR 1910.95(a)

In context

An enforcement, recordkeeping, or general-duty concept under the Occupational Safety and Health Act and 29 CFR. These terms define how OSHA inspects, cites, and penalizes employers.

29 CFR Chapter XVII

Where this is written in OSHA's rules

29 CFR 1910.95Read on eCFR / OSHA.gov
29 CFR 1926.52Read on eCFR / OSHA.gov
29 CFR 1910.95(a)Read on eCFR / OSHA.gov

Example

A concrete saw at a construction site measures an average of 103 dBA. Under OSHA's 5-dB exchange rate, the permissible unprotected exposure is 1 hour. The contractor installs blade dampening that reduces the saw to 97 dBA — permitting 3 hours. Workers in the zone wear double hearing protection (earmuffs over earplugs). Noise dosimetry is logged monthly; when a general industry subcontractor's crew enters the zone, they must be enrolled in the hearing conservation program per 1910.95 (85 dBA action level).

Why it matters

Noise-induced hearing loss (NIHL) is permanent and irreversible — there is no medical treatment to restore the cochlear hair cells damaged by excessive noise. OSHA cites noise violations under 1910.95 and the General Duty Clause. More than 22 million U.S. workers are exposed to hazardous occupational noise annually, and construction has one of the highest NIHL rates of any sector. Engineering controls implemented early prevent a permanent disability that affects earning capacity and quality of life for decades.

OSHA's 5-dB exchange rate vs. NIOSH's 3-dB exchange rate

OSHA uses a 5-dB exchange rate (halving exposure time every 5 dB) and a 90 dBA PEL, set in the 1970s based on engineering feasibility at the time. NIOSH recommends a 3-dB exchange rate (halving exposure time every 3 dB, which reflects the physics of acoustics) and an 85 dBA REL. Noise dosimeters report as a '% dose' under OSHA's criteria; 100% dose = 8 hours at 90 dBA. OSHA does not require administrative action until a worker reaches 100% dose, while NIOSH's tighter 3-dB criterion flags risk at 50%. For hearing conservation programs, many safety professionals apply NIOSH criteria as best practice even where OSHA does not require it.

OSHA Permissible Noise Exposure (Table G-16 — 29 CFR 1910.95)

Sound Level (dBA)	Permissible Duration (hr/day)
90	8
92	6
95	4
97	3
100	2
102	1.5
105	1
110	0.5
115	0.25 or less

Noise Exposure: frequently asked questions

What is the difference between the PEL and the action level for noise?: The PEL (90 dBA TWA) is the maximum legal exposure limit — exceeding it requires engineering or administrative controls before relying on hearing protection. The action level (85 dBA TWA) is the lower threshold that triggers a mandatory hearing conservation program in general industry: monitoring, annual audiometric testing, free hearing protection, and training. A worker between 85 and 90 dBA is not violating the PEL, but the employer must still implement the conservation program in general industry.
Does the construction noise standard require a hearing conservation program?: Yes — and the confusion is worth clearing up, because the two halves of this question have different answers. **The program itself is required**: 29 CFR 1926.52(d)(1) says that “in all cases where the sound levels exceed the values shown herein, a continuing, effective hearing conservation program shall be administered”. The trigger is Table D-2 — 90 dBA over 8 hours, sliding to 115 dBA at 15 minutes. **What is not codified for construction is the programme's CONTENT.** The 1983 Hearing Conservation Amendment — monitoring, baseline and annual audiograms, annual training, protector fitting, and the 85 dBA action level — was written into 1910.95(c)-(o) and never extended to construction. OSHA's 1992-08-04 interpretation letter names seven elements it expects and says a programme must incorporate as many as are feasible: a performance standard, not a checklist. State Plans may go further — Washington applies its full hearing-loss-prevention chapter to construction work (WAC 296-155-210), action level included.
When are engineering controls required instead of just providing earplugs?: Under 29 CFR 1910.95(b)(1), engineering or administrative controls are the primary required approach when noise levels exceed the PEL (90 dBA TWA). Hearing protection devices (earplugs, earmuffs) are the required supplement when controls are not feasible or cannot reduce exposure below the PEL. For workers exposed between 85–90 dBA under the action level, hearing protection devices are the primary protection — but the employer must also ensure they are worn correctly and are adequate for the noise level.

More OSHA terms

Abatement

The action an employer takes to fix a cited violation or eliminate a hazard OSHA identified during an inspection. The citation sets an abatement date, the deadline to correct the hazard, and within 10 calendar days after that date the employer must certify to OSHA that the violation was abated. Failure to abate accrues additional penalties of up to $16,550 per day.

Area Director

The senior OSHA official in charge of a specific OSHA Area Office — the local unit that runs inspections and enforcement in its geographic territory. The Area Director has the authority to issue citations, propose penalties, hold informal conferences with employers, and approve settlement agreements. When a Compliance Safety and Health Officer (CSHO) completes an inspection, it's the Area Director who ultimately issues the citation.

Bureau of Labor Statistics (BLS)

The federal statistical agency within the U.S. Department of Labor that collects, analyzes, and publishes data on workplace injuries, illnesses, and fatalities. BLS conducts the annual Survey of Occupational Injuries and Illnesses (SOII) — compiled from employer OSHA 300 logs — and the Census of Fatal Occupational Injuries (CFOI). SOII data drives OSHA's Site-Specific Targeting (SST) program: establishments whose DART rates significantly exceed their BLS industry average are placed on the SST inspection list.

Competent Person

Under OSHA's construction standards, a person who is capable of identifying existing and predictable hazards in the surroundings or working conditions, and who has the authorization to take prompt corrective measures to eliminate them. The role requires both knowledge and the authority to act, and is mandated by name in many specific standards — excavations, scaffolds, fall protection, asbestos, and more.

Citation

The formal written notice OSHA issues to an employer after an inspection, describing each alleged violation, the standard cited, the proposed penalty, and the date by which the hazard must be corrected (abated). OSHA must issue a citation with reasonable promptness and no later than six months after the violation occurred.

Closing Conference

The meeting at the end of an OSHA inspection where the compliance officer confers with the employer and informally advises them of any apparent violations found. Importantly, the closing conference discusses what was observed and the employer's rights — but it does NOT state final citations or penalties, which come later in the written Citation and Notification of Penalty.

Compliance Officer (CSHO)

An OSHA Compliance Safety and Health Officer — the inspector who conducts workplace inspections. A CSHO presents credentials (a photo ID and a serial number), holds the opening conference, performs the walkaround, collects evidence, interviews employees, and recommends citations. CSHOs are either safety specialists or industrial hygienists.

Contest

An employer's formal challenge to an OSHA citation, penalty, or abatement date. To contest, the employer must file a written Notice of Contest with the OSHA Area Director within 15 working days of receiving the Citation and Notification of Penalty. Filing sends the case to the independent Occupational Safety and Health Review Commission (OSHRC); missing the deadline makes the citation a final, un-appealable order.

Sources & verification

Reviewed by HazComFast against eCFR, OSHA.gov, NIOSH, and the Federal Register. Last reviewed 2026-10-05. This glossary is general information, not legal advice; OSHA State-Plan states (e.g. California, Michigan) may adopt stricter requirements.

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