Sarah Broadbent, Technical Affairs Engineer - Occupational Health
and Environmental Safety, 3M
Hearing loss is one of the most common industrial injuries which can affect workers. However, not enough workers understand the importance of hearing protection for their day-to-day work. Even though the Control of Noise at Work Regulations 2005 governs the provision of hearing protection, it can be difficult in some work places to enforce them.
The construction industry was one of the sectors with the highest annual average of new cases qualifying for Industrial Injuries Disablement Benefit (IIDB) (based on 2006-08 figures) for noise-induced deafness, according to the Health and Safety Executive (HSE).
The Control of Noise at Work Regulations 2005 state that employers must offer suitable hearing protection where noise exceeds 80dB(A). They also state that at levels above 85dB(A) hearing protection must be used. Despite this, there is often resistance to hearing protection from individual workers and in situations where someone is self-employed, it can be difficult to install a management mechanism for enforcement.
The potential noise hazards in the construction industry are numerous and can come from many sources. The HSE has a table that gives some indications as to the noise levels that certain activities can reach. For example, concrete pouring, sandblasting, scabbling and blasting can all reach levels of 85dB or more, which is the upper action value at which Hearing Protective Equipment (HPE) is required to be worn.
Construction workers may also be using their own tools which produce high noise levels above 85dB, such as compactors, chainsaws, needle guns and grinders.
Furthermore, it is important to note that noise exposure may not only come from the equipment that a worker is using, but from adjacent fixed plant or noisy tools being used by a co-worker. Assessment of the likely noise sources is, therefore, crucial.
Measuring noise levels
Assessing noise levels on site can be tricky as construction sites
are often transient, making it difficult to have defined zones for
controlled hearing protection at all times.
Noise indicators, which can be clipped on to an individual’s clothing, give an instant indication of the noise levels in an environment and, therefore, when hearing protection should be worn. The product flashes red or green depending on whether the noise level is above 85dB(A) indicating the need for HPE.
Static noise indicators, meanwhile, measure the noise level in an environment providing a colour-coding system which can then be checked against a list of products offering protection from that level of noise.
Clients and designers can help to reduce noise levels in the workplace by eliminating the noise sources on site, by prefabricating components offsite and by specifying working methods that do not require noisy tools and processes.
Alternative work methods or processes may be considered while thought should also be given to mechanising or automating work so that the worker is removed from the noisy environment.
When selecting equipment to carry out work, careful consideration about its suitability for the job can dramatically assist noise control. Older and worn out equipment will generally be noisier and may take more time to do the job, exposing the worker to high noise levels for longer than necessary. Similarly, tools that produce the least noise should be selected. Sometimes, hiring equipment can help as hired products are usually nearly new or well-maintained.
Key factors affecting specification
HPE products must be suitable for the work being carried out – they
should be durable enough for their environment and not cause the
worker to adjust them regularly. HPE must be compatible with other
personal protective equipment (PPE) being worn – for example, a
worker needing to wear a hard hat and safety eyewear could consider
helmet mounted earmuffs and eyewear that neatly attaches to the
helmet. Alternatively, ear plugs or banded earplugs which sit under
the chin or behind the neck may be more appropriate. Ear muffs can
be supplied in high-visibility colours, further assisting with
worker visibility on site.
The HPE chosen must also account for the pattern of noise exposure – for example, continuous noise or intermittent loud noises. HPE products exist with built-in communication devices for workers who need to be in contact during construction tasks. Some HPE offers built-in communication radios or level-dependent ear muffs which electronically analyse the sound before transmitting it to the ear. They can amplify quieter noises to enhance vital communication and at the same time attenuate the louder, impact noises. This avoids the need to lift the product off the ear to listen to a colleague or take a phone call. Bluetooth can also be built into HPE, offering more advanced communication and radio capabilities. These products can be linked to the site office or base control ensuring all site workers are linked in to important announcements.
The environment in which the product is to be used is a key consideration when choosing between disposable and reusable HPE – products used in particularly dirty or dusty environments are likely to require regular maintenance in the form of cleaning and daily visual inspections for wear and damage. However, for HPE to remain effective, it is a legal requirement to ensure a stringent care and maintenance policy is in place and that employees carry out simple pre-use and post-use checks and any necessary monthly maintenance tasks.
Comfort and user acceptance are vital, with even a small period of non-usage due to discomfort or removing the HPE (for example, to listen to someone talk) potentially having a significant effect on the protection offered. For example, simply not wearing the HPE for 30 minutes during an eight-hour exposure will reduce the HPE attenuation to near zero. The selection process should also establish whether the worker has any medical disorder that could influence the selection. This might include persistent earaches, irritation of the ear canal, discharge, hearing loss, or any type of individual sensitivity to noise. Where employees have such medical conditions, the employer should seek medical advice as to the suitability of hearing protection.
Once the decision on HPE has been made, it is not acceptable simply to provide HPE to employees and expect that to be enough. It is a legal requirement that training and information be provided. This should include correctly fitting the HPE, when to put it on, how to care for and maintain the products, and ensuring that a health surveillance programme is in place. This sort of information and training programme can be taught through toolbox talks and refresher training at regular periods throughout the project.
Fit validation equipment exists for ongoing verification of product performance and individual training on usage. These systems determine an employee’s Personal Attenuation Rating (PAR) in just a few seconds by providing ‘real fit real time’ results - they assess whether or not products are being correctly fitted and used and therefore whether the products are providing suitable levels of protection.
The HSE has also provided a flow chart of managing noise risks on a construction site – for more information visit www.hse.gov.uk.