Earplug Guide

View as PDF
How are earplugs rated?

Earplugs are evaluated by Noise Reduction Rating, or NRR. This describes the maximum sound level reduction provided by a hearing protection device.

How to use the noise reduction rating
  • 1. Subtract 7 from the earplugs' NRR.

    29 NRR (earplugs) – 7 dB = 22 dB

  • 2. Divide the result by 2 to determine the real-life reduction.

    22 dB ÷ 2 = 11 dB

  • 3. Subtract the real-life reduction from the environmental noise level to get the protected exposure level.

    90 dB (environment) – 11 dB = 79 dB
    (protected exposure level)

How to use the noise reduction rating
  • 1. Subtract 7 from the earplugs' NRR.
  • 2. Divide the result by 2 to determine the real-life reduction.
  • 3. Subtract the real-life reduction from the environmental noise level to get the protected exposure level.
Example
  • 29 NRR (earplugs) – 7 dB = 22 dB
  • 22 dB ÷ 2 = 11 dB
  • 90 dB (environment) – 11 dB = 79 dB
    (protected exposure level)
Uline Bullet Earplugs
Environmental Noise Levels
Faint 10 dB Normal breathing
40 dB Refrigerator, quiet office
Moderate 50 dB Paper rustling
60 dB Normal conversation, dishwasher
Loud 75 dB Alarm clock, vacuum cleaner
85 dB Conveyor, hand saw
Extremely Loud 90 dB Lawn mower, pneumatic wrench, compressor
100 dB Power tools, bulldozer
110 dB Ambulance siren, crying baby
Painful 120 dB Sandblasting, hammer on nail
140 dB Jet engine, dynamite blast
160 dB Firearm, fireworks
170 dB Rocket liftoff
11/05/2024 12:23:45 AM; CNWEB23 -0-0/0.0-1- 00000000-0000-0000-0000-000000000000