What is over-protection and is it bad?
This is one of those woolly areas of safety where there is no hard and fast rule, and what counts as over-protection and any subsequent risks arising from it will change from company to company.
What is ‘over protection’?
It means the hearing protection is too strong for the noise risk present and is reducing the noise levels too much. This is considered to be a problem.
Under protection versus just-the-right-amount of protection
There is no definite figure which counts as ‘over protection’ and it is a matter of judgement. Importantly, if you have some jobs where a type of hearing protection is just right, and for other jobs it is perhaps a bit too strong, err on the side of caution as you will not damage someone’s hearing from over-protecting, but you can from under-protecting.
What counts as over-protection?
What is defined as over-protection can vary. In our risk assessments we define it as below about 60 dB. This is actually very quiet but it is the typical level of a quiet office or someone’s house and seems to be a reasonable noise level to let someone work at every day. (The World Health Organisation identifies increased health risks from noise levels over this, so technically, people in the 60s dB and upwards have a tiny increased health risk from noise). Personally, we are happy at that noise level.
What is the risk of over protection?
Put simply, isolation. This can mean people cannot hearing vehicle movements in their area, such as forklifts, or they cannot hear things like fire alarms. Maybe they cannot hear people talking and then the risk is they remove the protection to talk to other people. This can be a problem and can dramatically increase their daily noise exposure.
This is a worked example:
An employee works in an area of 100dB for 8 hours. They wear hearing protection which brings their exposure level down to 75dB, which is pretty much perfect. During the day they remove the hearing protection for three periods of five minutes each to talk to someone, a total of 15 minutes out of the working day. This means they are wearing hearing protection for 7¾ hours, and not wearing it for only 15 minutes. But, the effect of this is to increase their total noise exposure for the day to 85dB, well into the area known to cause hearing loss.
What about different protection for different jobs?
This would be nice, but it is not practical in many workplaces as it would be the same person having different hearing protection for different jobs. While the theory of that is great, in practice it will never work in a month of Sundays. They will end up wearing one type all the time, and often will choose the lesser protector meaning that despite the over-protection being mitigated, they are now potentially exposed to too-high noise levels.
What should the employer do?
Firstly, assess your hearing protection’s performance levels. Then, if you have protectors which are over-protecting for all your noise risks, move to one which is a bit less meaty.
If you have a mixed noise risk so have some jobs where the protector is too much, but others where it is about right, check that people working in the over-protected area can still hear things like forklifts and alarms, and if so then live with it. It is better to over-protect than under-protect - you aren’t going to damage anyone’s hearing with over-protection but you will with under-protection.