3M 1426 Ear Muff

HSN:39269099. GST@18% extra.
Dispatch on next working day.



 Soft foam ear cushions provide comfort and secure fit
 Can be worn with the headband behind the head for compatibility with hard hats
 Ear cups adjust easily for a customized fit
 Noise Reduction Rating: 21 decibel
 Color is red and black
 One size fits for all
Understanding Decibals(dB), SNR, NRR and exposure levels

Decibel(dB) is the unit used to measure the intensity of a sound 

150 dB = Rock Concerts at Peak 
140 dB = Firearms, Air-Raid Siren, Jet Engine 
130 dB = Jackhammer 
120 dB = Jet Plane Take-off, Amplified Music at 4-6 ft 
110 dB = Machinery, Model Airplanes 
100 dB = Chain saw, Pneumatic Drill 
090 dB = Truck Traffic, Subway 
080 dB = Alarm Clock, Busy Street 
070 dB = Vacuum Cleaner 
060 dB = Conversation, Dishwasher 
050 dB = Moderate Rainfall 
040 dB = Quiet room 
030 dB = Whisper, Quiet Library 

Recommended Noise Exposure levels
Level of noise     Maximum daily 
    in dB(A)       exposure time  
      85             8 Hours 
      91             2 Hours 
      97            30 Minutes 
     103            07 Minutes 

SNR Single Number Rating is the rating system set up by the
European Union (EU). NRR Noise Reduction Rating is a rating
system set up by the Environmental Protection Agency (EPA), USA. 

OSHA Standards for Calculation of hearing protector

For all types of hearing protection, OSHA’s derating factor is 50%.
If used with C-weighted noise, the derated NRR will become NRR/2. 
If used with A-weighted noise, OSHA applies the 7-dB adjustment for
C-A weighting first then derates the remainder. The Derated NRR for
a ear plug with 33-dB NRR used at 

(1) A-Weighted noise: Derated NRR = (33 – 7)/2 = 13 db 
(2) C-Weighted noise: Derated NRR = 33/2 = 16.5 db 

Example: if you are at a factory with machinery noise exposure level 
at 100 dB and you are wearing a ear plug with an NRR 33 dB, your new 
level of noise exposure is 87 dB. i.e. (33-7)/2 =13. 

If you are wearing a product with an NRR of 27 dB it would deduct 
10 decibels from the environment noise level. i.e. (27-7)/2=10. 

NRR vs SNR Definitions 
There is no direct conversion but a reasonably accurate guide is 
NRR + 2 or 3 = SNR. Example NRR 22 = ± SNR 25

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