Maximum sound level for FA

[Tom Sutton]

I received the following enquiry today and wonder if any of you experts could help for instance is there is any H&S legislation being infringed?

We are the owners/landlords of a five-storey office block which has an old alarm system.  We carry out fire drills every 6 months and I have had comments/complaints about the high volume of the alarm.  I can find details of the minimum decibels required but can't find anything to clarify if there is a maximum.  I did get our testing engineer to check it for us a while ago and, from memory, it was about 100 which I appreciate is loud, but I am trying to find out if I am contravening any legislation.

[Galeon]

I have had this issue before , and outside the realms of the B.S  , you will be looking at levels past 95 dB in relation to possible hearing damage etc etc.
We still find people installing crazy sound levels say in staircase's where it is obvious disorientation during escape will occur.
What we are actually trying to achieve with the the audible alarm , is a good overall well distributed compliant sound pressure level.
As you well know is many systems were installed in a poor manner , ie the sounder was fitted onto of the control panel , belting our 105 db so to achieve 65 db in the toilet down the corridor, and the poor receptionist couldn't conduct a possible call to the Fire Service if he/she wanted to.

[nearlythere]

I received the following enquiry today and wonder if any of you experts could help for instance is there is any H&S legislation being infringed?

We are the owners/landlords of a five-storey office block which has an old alarm system.  We carry out fire drills every 6 months and I have had comments/complaints about the high volume of the alarm.  I can find details of the minimum decibels required but can't find anything to clarify if there is a maximum.  I did get our testing engineer to check it for us a while ago and, from memory, it was about 100 which I appreciate is loud, but I am trying to find out if I am contravening any legislation.

Refer to "The Control of Noise at Work Regulations 2005"

[Graeme]

120 dBa to BS

[Graeme]

in saying that the sounders output should be relevant to their enviroment

i.e small room  should be 65 or slightly above not 120,so it could be a case that a more suitable sounder could be installed as not to cause panic when it goes off.

[kurnal]

The Noise at Work Regulations apply to Workplaces and specific provisions cover noise levels in workplaces and places of entertainment.  Nowhere do the Regs refer to emergency alarms. However there is a duty to assess all potentially harmful sources of noise and use risk assessment techniqes to eliminate or reduce the potential for harm.

Some very loud noise levels can cause immediate (or acute) harm - these are related in terms of Db or pascalls- sound pressure levels. Other noises in the workplace can also cause harm - this is related to both the duration of the exposure and the noise levels. Theres lots of info on the www.hse.gov.uk website and I wont repeat it here.

But nowhere will you find a special reference to fire alarms. Because its just another workplace noise and should be controlled using the principles of prevention just like any other noise hazard.  Theres no need for too much sound and no excuse for it. Poor design , poorly set up equipment all of which can be dealt with fairly easily and cheaply. More quieter sounders than few very loud ones. Many sirens can also be controlled- with loud and quieter settings. The duty is to eliminate or minimise the risk of harm as far as is reasonably practicable.

[AnthonyB]

It's not uncommon for very old systems to use a small number of very loud sounders, either bells or for real earwax blasting motor driven klaxxons - normally the same model that used to be on the roof of a factory to signal lunch time & home time.

However another common factor with these really old systems with motor klaxxons is they are often 240V only & so should be being replaced anyway.

Even sounders on 24V systems can be very loud and common sense should be used in their placement - better to have several lower volume sounders than a couple of mega loud ones - this also reduces the consequences from a sounder failure: On an old system one bell failure could leave a whole floor unaware, whilst a modern well planned replacement with two or threelower power sounders on the same floor would still alert most people on the floor if one failed.

[Allen Higginson]

in saying that the sounders output should be relevant to their enviroment

i.e small room  should be 65 or slightly above not 120,so it could be a case that a more suitable sounder could be installed as not to cause panic when it goes off.

60 dB also acceptable for cellular offices,taircases and on other areas where 65dB is generally reached.
I have had sites where they had installed 24vdc motor driven sounders to achieve audibility in flats - bleeding ear canals spring to mind!!!

[Tom Sutton]

Thanks for all your comments