I have just been advised on a RA submitted and was surprised by this particular comment.

"Would remove SNR 37 for hearing protection as this would fall below the recommended minimum noise level of 70dB when using tools ranging from 86dB – 101dB"

The ear plugs/ defenders we supply our operatives as standard are 37 SNR. I have never been questioned on this before and now I am doubting myself. I had never heard of a minimal recommended noise level of 70dB - is this a thing, or should I argue this back?

Two Questions to ask; 

1. Recommend by whom?

2. What is the risk of not being able to hear below 70dB as if hearing protection is required in some areas to protect from 85dB and above how does the mimum risk of 70dB not still exisit?

I do belive you should be asking if the other one has bells on

There is a chance that by using a higher SNR than required workers can become disconnected and less aware of things going on around them, I would imagine thats what they were getting at.

70 dB comes from hse

see link below

http://www.hse.gov.uk/noise/goodpractice/hearingoverprotect.htm

Originally Posted by: PeteCharlesworth

70 dB comes from hse

see link below

http://www.hse.gov.uk/noise/goodpractice/hearingoverprotect.htm

I am surprised that the HSE actually set a level. Of course, this is guidance and there is no actually legally enforceable level. The principle is that you do not eliminate all noise with hearing protection, just reduce it to an acceptable level.

70 dB is not that loud, remembering that the dB is a logarithmic scale and 70 dB is one tenth of the energy of 80 dB and normal conversation is in the 60-70 dB range.

As I'm sure you all know, SNR = Single Number Rating, which is a very quick guide as to the level of protection that hearing protection offers (if fitted correctly). therefore at a level of 85dB(A), using an 'ear plug' with a rating of  SNR37, this would in effect reduce the level of noise in the ear to 48dB(A) - again the disclaimer, if fitted correctly.  Our general speech is around 60-65dB(A), so it is particularly dangerous to use that level of protection.  Of course, most people do not fit plugs correctly, so the level of protection is typically reduced by 4-6dB(A).

Remember in terms of PPE, one size doesn't fit all!

I have always treated SNRs much like Volkswagen's emmisions data  

Taken from the HSE website http://www.hse.gov.uk/noise/calculator.htm

Select a protector so that daily exposure is reduced to at least below 85 dB.  Ideally, aim for between 80 and 75 at the ear.  Avoid protectors resulting in less than 70 dB at the ear - this is 'over-protection' (see BS EN 458:2004).

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