OSHA Noise Exposure Limits (2026 Guide)
What are the OSHA noise exposure limits?
Short answer: OSHA noise exposure limits run on two numbers. The permissible exposure limit (PEL) is a 90 dBA time-weighted average over 8 hours — above it, employers must use controls and mandatory hearing protection. The action level is 85 dBA TWA — above it, a full hearing conservation program kicks in: noise monitoring, annual audiograms, hearing protectors offered, and training. Both come from 29 CFR 1910.95, which also caps shorter, louder exposures on a sliding scale — 95 dBA is allowed for only 4 hours, 100 dBA for 2, and 115 dBA for just 15 minutes.
The controlling text is 29 CFR 1910.95, Occupational Noise Exposure, and its Table G-16 duration schedule. NIOSH — the research agency, not the enforcer — recommends a stricter limit: an 85 dBA recommended exposure limit with a 3-dB exchange rate, per the NIOSH occupational noise criteria. Understanding where OSHA's floor ends and NIOSH's recommendation begins is most of what a safety manager needs to run a defensible program.
This guide is written for safety managers standing up or auditing a hearing conservation program, supervisors reading a noise survey, and workers deciding what the readings on the sound level meter mean for their ears. It walks the two trigger numbers, the full Table G-16 schedule, the OSHA-vs-NIOSH exchange-rate difference, what the program requires, and a worked example protecting a 92 dBA shop.
Why this matters.
NIOSH estimates about 22 million U.S. workers are exposed to potentially damaging noise each year, and occupational hearing loss is one of the most common work-related illnesses — permanent, incurable, and entirely preventable. It is also invisible on the day it happens: noise-induced hearing loss accumulates shift by shift, which is exactly why 1910.95 forces measurement and audiometric testing instead of waiting for symptoms. See the NIOSH noise program for the underlying research.
The two numbers that run everything: 90 and 85
90 dBA — the permissible exposure limit
1910.95(b) sets the PEL at a 90 dBA 8-hour time-weighted average. At or above it, the employer must first apply feasible engineering and administrative controls (quieter machines, enclosures, rotation), and where those fail to bring exposure under the limit, hearing protectors become mandatory — not optional equipment.
85 dBA — the action level
1910.95(c) starts the hearing conservation program at an 8-hour TWA of 85 dBA (equivalently, a 50% noise dose). Below the PEL but at or above the action level, protectors must be made available and the full program — monitoring, audiograms, training, recordkeeping — must run. The 5-dB gap between 85 and 90 is where most real-world programs live.
Table G-16: how long is legal at each level
The PEL is not a ceiling on loudness — it's a ceiling on dose. Table G-16 trades intensity for time using OSHA's 5-dB exchange rate: every 5 dBA increase halves the permissible duration.
| Sound level (dBA, slow response) | Permissible duration per day | Typical source at this level |
|---|---|---|
| 90 | 8 hours | Shop machinery, lawn mower |
| 95 | 4 hours | Belt sander, loud tractor cab |
| 100 | 2 hours | Circular saw, jackhammer at distance |
| 105 | 1 hour | Chainsaw, angle grinder close-up |
| 110 | 30 minutes | Riveting, loud concert floor |
| 115 | 15 minutes — the standard's short-duration ceiling | Sandblasting, planer |
Where the day mixes levels, 1910.95 Appendix A computes a combined dose — the arithmetic our free noise dose calculator automates. For a plain-English tour of what common tools and environments measure, see the decibel levels chart.
OSHA vs NIOSH: the exchange-rate argument
The two agencies agree noise destroys hearing and disagree on the math:
| Parameter | OSHA (enforceable) | NIOSH (recommended) |
|---|---|---|
| 8-hour limit | 90 dBA PEL | 85 dBA REL |
| Exchange rate | 5 dB halves the time | 3 dB halves the time (equal-energy) |
| 100 dBA allowance | 2 hours | 15 minutes |
| Legal force | Citable minimum | Best practice many programs adopt voluntarily |
The practical read: compliance is judged against OSHA's numbers, but a program designed to NIOSH's 85/3-dB criteria protects hearing considerably better — and several state plans and large employers run on it.
What the hearing conservation program requires at 85 dBA
Once any employee's 8-hour TWA hits the action level, 1910.95 requires the employer to:
- Monitor exposure. A noise survey identifying every employee at or above 85 dBA TWA, repeated when production, equipment, or controls change (1910.95(d)).
- Provide baseline and annual audiograms. A baseline within 6 months of first exposure, annual tests after, and evaluation for standard threshold shifts (STS) — the standard's definition of measurable hearing damage (1910.95(g)).
- Make hearing protectors available at no cost — with a selection to choose from, replaced as needed (1910.95(i)).
- Require protectors for anyone at or over the PEL, and for anyone with an STS exposed at or above 85 dBA.
- Train annually on noise effects, protector selection and fit, and audiometric testing purpose (1910.95(k)) — and keep exposure and audiometric records (1910.95(m)).
NRR on the package vs protection at the ear
Hearing protectors carry an EPA Noise Reduction Rating measured in a laboratory. Field protection is lower — fit, motion, and glasses temples leak noise — so OSHA's enforcement approach subtracts 7 dB from the NRR when comparing against A-weighted exposure, and applies further derating when evaluating real-world adequacy; NIOSH recommends derating by protector type (roughly 25% for earmuffs, 50% for formable plugs, 70% for pre-molded plugs). The takeaway isn't the exact formula — it's that a 25 NRR plug does not subtract 25 dB at the ear, and marginal situations deserve double protection (plugs plus muffs). Our highest-NRR earplugs guide ranks the ceiling of what single protectors deliver.
Worked example: protecting a 92 dBA fabrication shop
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A metal-fab bay surveys at a 92 dBA TWA with grinder peaks near 105 dBA. The compliance walk:
- Confirm where 92 dBA sits. It's above both triggers — the full hearing conservation program applies and protectors are mandatory, because 92 exceeds the 90 dBA PEL. Run the numbers for mixed exposures in the noise dose calculator.
- Try controls before earplugs. 1910.95(b) puts feasible engineering and administrative controls first — grinder wheel selection, barriers, rotating the loudest tasks across the shift all shave dBA before anyone reaches for PPE.
- Issue protectors that clear the math. A corded multi-flange plug like the 3M 1270 (NRR 25) — reviewed in our 3M 1270 review — comfortably brings a 92 dBA TWA under the action level even after conservative derating. Check price on Amazon
- Give the intermittent-exposure crew electronic muffs. Supervisors moving in and out of the bay do better with level-dependent earmuffs like the Decibel Defense NRR 37 electronic earmuffs — protection plus conversation between grinder cycles (the electronic-muff category is compared in Howard Leight Impact Sport vs Walker's Razor Slim). Check price on Amazon
- Book the audiograms and calendar the training. Baseline within 6 months for new hires in the bay, annual tests thereafter, annual training — the paperwork half of the program is what inspectors ask for first.
The full protector lineup we've evaluated is in the hearing protection collection, with muffs specifically in the ear muffs collection.
Edge cases the standard actually addresses
Impulse noise has its own ceiling
1910.95(b) caps impulsive or impact noise at a 140 dB peak — gunfire, powder-actuated tools, and drop forges can cross it in a single event, which is why shooting ranges are double-protection environments regardless of TWA.
Construction runs on a different section
Construction noise lives in 29 CFR 1926.52 with the same Table-G-16-style limits but a thinner program requirement — general-industry employers borrowing construction rules (or vice versa) is a recurring audit finding.
Hearing aids and buds are not protectors
Consumer earbuds playing nothing block almost nothing, and music at work adds dose. Only rated protectors count toward compliance.
Frequently asked questions
What is the OSHA noise exposure limit for 8 hours?
A 90 dBA time-weighted average — the permissible exposure limit in 29 CFR 1910.95(b). At or above it, feasible controls come first and hearing protection becomes mandatory.
What is the OSHA action level for noise?
85 dBA as an 8-hour TWA (a 50% dose). At or above it the employer must run a hearing conservation program: monitoring, baseline and annual audiograms, protectors made available free, training, and records.
How long can you work in 95 dBA under OSHA?
4 hours per Table G-16. At 100 dBA it's 2 hours, at 105 one hour, at 110 thirty minutes, and at 115 dBA fifteen minutes — each 5 dBA increase halves the time.
What is the difference between OSHA and NIOSH noise limits?
OSHA enforces 90 dBA with a 5-dB exchange rate; NIOSH recommends 85 dBA with a 3-dB exchange rate. The gap is largest at high levels — at 100 dBA OSHA allows 2 hours while NIOSH's criteria allow about 15 minutes.
At what noise level is hearing protection required?
Mandatory at or above the 90 dBA PEL, and for any employee with a standard threshold shift exposed at or above 85 dBA. Between 85 and 90, protectors must be offered and the program must run, but wearing them is not yet compulsory under the federal rule.
What is a standard threshold shift (STS)?
An average 10 dB or greater worsening at 2000, 3000, and 4000 Hz in either ear relative to the baseline audiogram — the standard's tripwire that converts optional protection into mandatory protection and triggers follow-up requirements.
Does an NRR 25 earplug reduce noise by 25 decibels?
Not in the field. OSHA's enforcement approach subtracts 7 dB from the NRR against A-weighted readings and derates further for real-world fit; NIOSH derates by protector type. Treat a 25 NRR plug as roughly 9–18 dB of practical protection depending on the method — details in our highest-NRR guide.
What decibel level is a standard threshold for the hearing conservation program in construction?
Construction runs under 29 CFR 1926.52 with the same 90 dBA/5-dB table; its hearing-conservation language is less prescriptive than general industry's 1910.95 program — many contractors voluntarily run the 1910.95 program anyway.
What is the OSHA limit for impulse or impact noise?
A 140 dB peak sound pressure ceiling. Single events — gunfire, powder-actuated fasteners — can exceed it instantly, which is why impulsive environments call for double protection regardless of the average level.
How is noise dose calculated for a mixed shift?
Each exposure segment contributes time-at-level divided by time-allowed-at-level; the segments sum to a total dose where 100% equals the PEL. 1910.95 Appendix A defines the formula, and our noise dose calculator runs it for you.
Do employers have to pay for hearing protection?
Yes — protectors must be provided at no cost to employees in the program, with a selection of suitable options and replacement as needed (1910.95(i)).
How loud is 85 dBA in everyday terms?
Roughly heavy city traffic heard from inside a car, a busy restaurant kitchen, or a gas lawn mower at operator distance — the zone where damage accumulates over full shifts without feeling painfully loud. Anchor your intuition with the decibel levels chart.
Are audiograms required every year?
Yes for every employee at or above the action level: a baseline within 6 months of first exposure (with quiet time or protectors beforehand), then annual audiograms compared against baseline for STS evaluation.
Can music earbuds count as hearing protection?
No. Consumer earbuds carry no NRR and streaming audio adds exposure. Only EPA-labeled protectors count — and some electronic muffs combine protection with communication for intermittent-noise roles.
What noise level requires double hearing protection?
The standard doesn't set an explicit dual-protection trigger, but common practice (and MSHA's rule for coal) treats TWAs at or above ~100–105 dBA and all impulse-heavy work as plugs-plus-muffs territory, since single-protector field performance tops out in the high teens of dB.
Who enforces noise limits — OSHA or NIOSH?
OSHA (and state plans) enforce; NIOSH researches and recommends. Citations reference 1910.95's numbers, while NIOSH's 85/3-dB criteria are the voluntary gold standard many programs adopt.
Further reading on this site
- Decibel levels chart — everyday and industrial sources mapped to dBA, the intuition layer under this standard.
- Noise dose calculator — the Appendix A mixed-exposure math, automated.
- Highest NRR ear plugs — the ceiling of single-protector performance, ranked.
- Hearing protection collection — every plug and muff we've evaluated.
- Howard Leight Impact Sport vs Walker's Razor Slim — the electronic-muff head-to-head for intermittent noise.
- Ear muffs collection — passive and electronic muffs by NRR.
Why trust this guide? WC Safety is an independent safety-equipment research and review site — we hold no inventory and take no manufacturer sponsorships. This guide was authored by our editorial desk, not by any protector maker or paid third party. Every limit cited is cross-referenced against 29 CFR 1910.95, OSHA's occupational noise page, and the NIOSH noise criteria. WC Safety earns Amazon affiliate commissions on outbound clicks; that never influences the limits or program requirements described.
Authored by Steven Eaton, WC Safety Editorial — Hearing conservation desk · specialization: 29 CFR 1910.95 program requirements, noise dose computation, hearing protector selection and derating.
Last reviewed: · Sources reviewed: 29 CFR 1910.95 including Table G-16 and Appendices A and I, OSHA occupational noise guidance, OSHA Technical Manual Section III Chapter 5, NIOSH occupational noise exposure criteria (85 dBA REL, 3-dB exchange rate), 29 CFR 1926.52.
Editorial standard: Zero sponsored listings. No manufacturer input. No paid placement on this page. Every exposure limit cited has been checked against the current regulatory text.
Last reviewed: · Sources reviewed: 29 CFR 1910.95 including Table G-16 and Appendices A and I, OSHA occupational noise guidance, OSHA Technical Manual Section III Chapter 5, NIOSH occupational noise exposure criteria (85 dBA REL, 3-dB exchange rate), 29 CFR 1926.52.
Editorial standard: Zero sponsored listings. No manufacturer input. No paid placement on this page. Every exposure limit cited has been checked against the current regulatory text.
How this guide was researched. Primary sources: 29 CFR 1910.95 via OSHA and eCFR, the OSHA occupational noise overview, the OSHA Technical Manual noise chapter, and NIOSH noise criteria. Reviewed quarterly and on any rulemaking affecting 1910.95 or 1926.52.
Disclosure. WC Safety participates in the Amazon Services LLC Associates Program; we earn commissions on qualifying purchases made through links on this page, at no additional cost to you. We do not sell products directly and hold no inventory. This article is educational reference content, not industrial-hygiene or legal advice — noise surveys, dosimetry, and program design for commercial workplaces should be confirmed with a Certified Industrial Hygienist (CIH) or your OSHA consultation program.
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