What is a safe decibel level and when is hearing protection required?

Short answer: Sound below about 70 dBA is generally safe for unlimited exposure; damage risk begins around 85 dBA and rises sharply above it. OSHA's noise standard requires hearing protection once an 8-hour time-weighted average reaches 90 dBA, and a hearing conservation program at 85 dBA. This decibel levels chart shows where common tools fall and how long you can be exposed before protection is mandatory.

Decibel levels chart: common noise sources and OSHA exposure limits (2026)

Noise damage is cumulative, permanent, and entirely preventable. The decibel (dB) scale is logarithmic, so every 10 dB increase represents a tenfold jump in sound intensity — which is why a jackhammer is not "a bit louder" than conversation but roughly a million times more intense. OSHA's occupational noise standard, 29 CFR 1910.95, and the stricter NIOSH recommended exposure limit set the thresholds this decibel levels chart is built around. This guide is written for safety managers, supervisors, and trade workers who need to know which tasks require hearing protection and how to choose it. We chart noise sources by dBA, lay out the OSHA exposure limits, and show how to convert a noise level into the right NRR.

Why this matters.
Noise-induced hearing loss is the most common recordable occupational illness, and it is irreversible — there is no surgery or hearing aid that restores damaged cochlear hair cells. OSHA 29 CFR 1910.95 requires employers to act at 85 dBA and to provide protection at 90 dBA, and the CDC estimates millions of U.S. workers are exposed to hazardous noise every year. Reading the chart correctly is the first control.

Part 1 — How the decibel scale works

Sound pressure is measured in decibels (dB); occupational noise uses A-weighting (dBA) to match how the human ear responds. Because the scale is logarithmic, the numbers do not add the way you would expect: two machines at 90 dBA each combine to about 93 dBA, not 180. The practical takeaway is that small-looking increases are large real increases, and the safe exposure time roughly halves for every few dB above the limit.

Part 2 — Decibel levels chart: common noise sources

Approximate A-weighted levels for everyday and worksite sounds. Use it to estimate whether a task crosses into the hazard zone:

Any task in the highlighted rows or below needs hearing protection from our Hearing Protection range — Foam Ear Plugs for high-attenuation tasks and Ear Muffs for intermittent exposure.

Part 3 — OSHA permissible exposure limits decode table

OSHA 1910.95 sets the permissible exposure limit (PEL) at 90 dBA for 8 hours and uses a 5 dB exchange rate — for every 5 dBA increase, the allowed time halves:

NIOSH recommends a stricter 85 dBA limit with a 3 dB exchange rate. The 85 dBA "action level" is where OSHA requires a hearing conservation program — covered in the OSHA 1910.95 hearing conservation guide.

Part 4 — How to use the chart to choose hearing protection

1. Identify the noise level. Measure with a sound level meter or dosimeter, or estimate from the Part 2 chart.
2. Find the exposure limit. Use the Part 3 table to see how long that level is permissible.
3. Calculate the reduction needed. Subtract your target safe level (85-90 dBA) from the measured level to find the attenuation required.
4. Convert to NRR. Apply the OSHA derating to the printed Noise Reduction Rating — see the NRR guide for the math.
5. Select and fit. Choose an earplug or earmuff with adequate NRR and insert it correctly — see how to insert foam earplugs.

Part 5 — Worked example: protecting a worker running a chainsaw

A landscaper runs a chainsaw at roughly 110 dBA. From Part 3, the unprotected limit at 110 dBA is just 30 minutes — far short of a workday. Here is the selection on real SKUs:

1. Determine the gap. To bring 110 dBA down to a safe 85 dBA at the ear requires about 25 dB of real-world attenuation.
2. Pick high-NRR foam plugs. The Howard Leight Maximum Max-1 (NRR 33) or Howard Leight Laser Lite (NRR 32) give the highest foam attenuation; even after derating they clear the 25 dB requirement.
3. Or choose reusable plugs. The Moldex 6800 Pura-Fit (NRR 33) is a high-attenuation foam option from the NRR 33 ear plugs range.
4. Add muffs for impulse spikes. Pair plugs with the 3M H10A Peltor Optime 105 ear muffs for dual protection when felling near other equipment.
5. Verify the fit. Attenuation only counts if the plug is seated correctly — follow the foam earplug insertion steps, and compare options in the highest-NRR earplug guide.

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Frequently asked questions

What is a safe decibel level?

Sound below about 70 dBA is safe for unlimited exposure. Risk of noise-induced hearing loss begins around 85 dBA, and the higher the level the shorter the safe exposure time, as shown in the decibel levels chart above.

At what decibel level is hearing protection required?

OSHA requires hearing protection when the 8-hour time-weighted average reaches 90 dBA, and a hearing conservation program at the 85 dBA action level. See the 1910.95 hearing conservation guide.

How loud is too loud?

As a rule of thumb, if you must raise your voice to be heard at arm's length, the environment is likely 85 dBA or higher and hearing protection is warranted.

How many decibels is a chainsaw?

A chainsaw runs roughly 105-110 dBA at the operator's ear, which limits unprotected exposure to about 30 minutes under OSHA's table. High-NRR protection is required for any sustained use.

How many decibels can damage hearing?

Prolonged exposure above 85 dBA causes gradual damage, and sounds at or above 120 dBA can cause immediate harm. Impulse noise like a gunshot (140+ dB) can damage hearing instantly.

What is the OSHA permissible exposure limit for noise?

90 dBA averaged over 8 hours, with a 5 dB exchange rate, so 95 dBA is allowed for 4 hours and 100 dBA for 2 hours. The ceiling is 115 dBA. See the Part 3 table.

What is the difference between OSHA and NIOSH noise limits?

OSHA's PEL is 90 dBA over 8 hours with a 5 dB exchange rate; NIOSH recommends a stricter 85 dBA with a 3 dB exchange rate. NIOSH's limit is more protective but advisory.

Does every 10 dB double the loudness?

A 10 dB increase is a tenfold increase in sound intensity and is perceived as roughly twice as loud. This is why the decibel scale's small numbers represent large changes.

How do I measure workplace noise?

Use a calibrated sound level meter for spot checks or a personal dosimeter for a full-shift time-weighted average. Estimate from the decibel levels chart only as a first screen.

What NRR do I need for 100 dB?

To bring 100 dBA down to a safe 85 dBA you need about 15 dB of real-world attenuation. Because printed NRR is derated in practice, choose a higher-rated plug — see the NRR guide for the calculation.

Are earplugs or earmuffs better for loud noise?

Both work; foam earplugs typically offer the highest attenuation, while earmuffs are faster to put on for intermittent noise. For very high levels, wear both. Compare in our earplugs vs earmuffs guide.

Can I just wear both earplugs and earmuffs?

Yes, "dual protection" is recommended above roughly 105 dBA. Combined attenuation is not additive — it adds about 5 dB over the higher-rated device alone, which is still significant.

How long can I be exposed to 95 dB?

OSHA permits 4 hours at 95 dBA without protection; NIOSH would limit it to about 1 hour. Use protection to stay under the limit for a full shift.

Is 85 dB dangerous?

85 dBA is the action level where damage risk becomes significant over a full shift. It triggers OSHA's hearing conservation program requirements, including monitoring and provided protection.

What hearing protection is best for construction noise?

High-NRR foam plugs or earmuffs suited to intermittent power-tool noise. See the construction hearing protection range and the best ear muffs for construction guide.

Further reading on this site

• What is NRR? — how to derate the rating to real-world attenuation.
• OSHA 1910.95 hearing conservation — monitoring, action level, and program rules.
• How to insert foam earplugs — roll, pull, hold for full attenuation.
• Hearing protection — full lineup of plugs and muffs.
• Highest NRR earplugs — top NRR 33 picks ranked.
• Best hearing protection — complete buyer's guide.
• Ear muffs — passive and electronic options.