It has been known for decades that it is virtually impossible to guarantee adequate protection from hearing protectors at noise levels above c 95dB(A). Consequently, it should not have been news that research by the Health and Safety Laboratory (report RR720) proved that the common assumption that PPE is a reliable “solution” to hearing damage risk problems is simply untrue. This assumption has left many personnel at risk and companies are open to claims if their hearing conservation policy is based on PPE use. Some of the key findings of the research are:-
- PPE in 25% of the companies visited was so ineffective that it provided negligible or no protection for most
- even in companies with effective PPE use, 14% of workers did not wear protectors when and where required
- 40% of the workers who should have been wearing protectors got no protection at all
The inadequacy of PPE performance in many real-world situations is also born out by the continuing tidal wave of hearing damage claims of £400 million in one year (2014 - IFA UK deafness working party), despite (or even because of) the over-reliance on PPE without understanding the performance limitations away from the lab. This also brings into sharp focus the need to reduce noise levels to reduce risk, even when the levels cannot be reduced to below 85dB(A).
As a rule of thumb, provided effective (and time-consuming) management systems are in place, most good quality PPE can be made to work up to noise levels of around 95dB(A). Above this level, it becomes increasingly difficult to guarantee sufficient protection and above c 100dB(A) it becomes virtually impossible.
The key (and very often missing) factors necessary to improve real world protection are:-
- you must have a system in place to audit wear rate. It is unbelievable that most organisatons do not log wear rates and consequently have no idea of the effectiveness of their PPE. Where appropriate, use the latest generation of intelligent PPE that logs wear rate and attenuation automatically.
- you must train staff in the correct fitting and use of PPE. This is particularly critical for ear plugs where the assumed protection of 30dB (manufacturer) often drops as low as 3dB in use.
In conjunction with the above, most organisations can cut risk by 50% - 90% at little or no cost (or even at a profit) by introducing very low-cost engineering noise control measures to reduce noise to levels at which PPE can be made to work. For example, reducing noise by 3dB from 97dB(A) down to 94dB(A) halves the risk (and PPE is more effective). Reduce the noise by 6dB and the risk falls by 75%.
There is more on the topic of self-financing noise control, including a White paper here.
Download a detailed article on inadequate real-world PPE performance >
