3M Foam Ear Plugs – 1110

From: 10.00


 Smooth, dirt resistance surface provides better hygiene.
 Earplugs are easy to roll down for quick and easy fitting.
 Tapered design fits comfortably in ear canals 
 Soft polyurethane foam is hypoallergenic.
 Noise Reduction Rating (NRR) 29 dB, CSA Class AL.
 Cord allows earplugs to be stored conveniently around
  the neck in between uses
 Colour: Orange
 Corded: Yes

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 in dB(A)     Maximum daily 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 

If you are at a factory with machinery noise exposure level 
at 100 dB and you are wearing a ear plug with an NRR 29 dB, 
your new level of noise exposure is 89 dB. i.e. (29-7)/2 =11. 

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