Have you heard about the Noise at Work Regulations? If you have, you’re luckier than some – they haven’t heard anything at all for years, or even decades.
Noise-induced hearing loss (NIHL) is frequently severe and always debilitating. It has been described by the World Health Organisation (WHO) as the most common permanent and preventable occupational injury in the world. The WHO also predicts that, by 2030, adult-onset hearing loss will be a top 10 disease in the UK, above cataracts and diabetes.
Some NIHL victims suffer tinnitus (a ringing, hissing or booming sensation in the ears); others are made totally deaf. Whatever form it takes, however, the disability has a shattering impact on those it affects.
Hearing loss caused by noise is irreversible. So prevention isn’t just better than cure, it’s the only alternative.
Indeed, around 170,000 people in the UK suffer ear conditions as a result of exposure to excessive noise at work, making it a pressing health and safety issue.
Brad Witt, director of hearing conservation at Honeywell Safety Products (http://bit.ly/1Q1ayHy), warns of the insidious nature of NIHL: “It’s a strange occupational injury. There is no pain, there’s no trauma, no scars. When we have a number of occupational injuries there is blood on the floor and broken bones. With hearing loss, there’s none of that.” Don’t be lulled into a false sense of security
He adds: “Without effective action to prevent NIHL, the bottom line is you will lose some hearing, but you are lulled into a false sense of security because it may not be immediately obvious.”
As well as safety concerns, there are also significant threats of litigation. As one factory manager told us: “Noise has become the new whiplash.”
Another said: “We have seen a steady stream of claims for noise-induced hearing loss which is consistent with the litigious society that we live in. Thankfully, our history of annual noise audits coupled with the pre-employment audiometry testing has had a significant impact on our ability to refute these claims.”
A third warned: “NIHL is starting to become a significant reason for claims from historical issues. However, there have also been more recent approaches by solicitors who contact every company a person has worked for; if you don’t have good records, systems and monitoring in place, you will be held responsible for at least part of any claim.”
The Control of Noise at Work Regulations 2005 insist that you, as an employer, ensure the risk of damage to your employees’ hearing from noise exposure is at the lowest level possible. You must assess and identify measures to eliminate or reduce the risk of exposure to noise by introducing control measures that are ‘reasonably practicable’ (in other words, in proportion to the level of risk).
So, where required, ensure that hearing protection is provided and used; any other controls such as noise barriers are properly used; and provide information, training and health surveillance. You should also review what you are doing if anything changes that may affect the noise exposures where you work.
Says Matthew Green, technical sales specialist – hearing protection at Arco (http://bit.ly/1GsgnIB): “It’s often very challenging and costly for companies to reduce noise at source by ‘buying quiet’ or engineering controls.
Therefore, hearing protection is provided and issued. This is usually selected following a noise assessment which tends to be conducted by external consultants.”
However, he warns: “Companies often struggle fully to understanding the context of [the consultant’s] report and need guidance from their personal protective equipment/safety suppliers. Education of the workforce to ensure selected hearing protection is worn needs to be included, something that can be forgotten or overlooked.”
Green says a noise assessment must be conducted if an employee is likely to be exposed at or above the lower action value defined in the regulations (80dB ‘eight-hour average’ or 135dB peak sound pressure): “Noise should be measured by a trained, competent person, either an external consultant or internal employee. It’s probably worth reviewing your noise assessment every three years or so, or when the working environment changes.”
Green defines four main types of noise: continuous, say, from machinery; intermittent, which can increase and decrease rapidly, perhaps caused by factory equipment that operates in cycles; impulsive – a sudden burst of sound caused, for example, by hammers; and low frequency, whether it’s the low background humming from power plants or the roaring of large diesel engines.
Sound is measured in decibels (dbA), a logarithmic scale. This means that every 3dBA effectively represents a doubling of the hazard.
To give you some idea for what different decibel values mean, a fairly quiet office will have a noise level of between 50 and 60dbA and the noise of heavy road traffic is normally 85 to 100dbA, while the sound of a jet aircraft taking off produces about 125dbA at a distance of 100m. This reflects the fact that distance affects noise levels: sound follows the inverse square law (doubling the distance from the source halves the noise level experienced).
Sudden or impact noises such as those caused by drop hammers or explosions are not perceived by the human ear as being as loud as they really are. While a cartridge tool may generate a noise which is really 140dbA, it may only seem to be about 90dbA. The problem is that it can still do the physical damage associated with 140dbA.
Although a sudden loud noise can rupture the ear drum, it is the damage to the inner ear structure that causes most work-related hearing loss. In general terms, this manifests itself initially in difficulty with hearing the higher frequencies. This might not be obvious to the individual, but would show up on an audiogram.
Honeywell’s Witt says employers should always view engineering controls or elimination of the noise as the first line of defence: “Many noise problems can be ameliorated quite easily just with vibration dampeners or enclosures such that noise exposures never exceed the hazardous level. It’s not cheap to invest in those sorts of engineering controls, but it will certainly resolve the problem at its source.”
“If those are not effective then we move to administrative controls. An example of that is rotating employees… so no single employee is overexposed to noise. The last line of defence is personal protective equipment,” adds Witt.
So where do you go for help to address the problem of noise at your factory? The library of resources available at www.hse.gov.uk/noise is really helpful. It offers a flowchart that walks you through the process of setting up a noise management programme, so that’s probably the best place to start.
Also, the British Safety Industry Federation has launched its ‘Listen Today, Hear Tomorrow’ campaign – see http://bit.ly/1L1SNV4 for details. This contains a wealth of information on how to decide whether noise in your factory is a problem and what to do about it if it is.
Finally, the ProtectHear website (http://bit.ly/1Q16Sp6) can point you to a range of useful links and resources on the subject of hearing protection.
Sound advice on noise assessment
It is your responsibility as a manager to protect your employees from dangerous workplace noise. But how do you know whether or not the risk exists? The answer is by conducting a noise assessment.
This starts with measuring the sound levels. People’s sensitivity to sound varies enormously depending on their own personalities, physiology and the degree to which they have been exposed to noise in the past. This makes the response to sound subjective.
That’s no good when you’re trying to evaluate, control and improve the noise climate.
Measuring sound enables you to come up with a standardised, objective scale which everyone accepts as the correct measure.
Noise is measured using sound meters. The type you use depends on the noise you want to measure. Three types of sound meter can be used to measure workplace noise.
The first two are handheld, the third is worn by the employee:
- Standard sound level meters provide a spot reading – good if noise levels are continuous with little fluctuation.
- Integrating sound level meters employ a microprocessor to calculate maximum level and time-weighted average eight-hour exposure.
- Dosimeters are for itinerant employees. They are essentially integrating sound level meters optimised to make a personal exposure measurement. However, dosimeters need to be used with caution: the fact that they are attached to the person means that they can’t be quite as accurate as handheld meters because of acoustic reflections from the head, body and clothing. And there is a problem of potential abuse by the wearer.
Hearing protection in a nutshell
Although it is no substitute for noise elimination or reduction, hearing protection can help prevent noise-induced hearing loss. Broadly, there are four categories:
- Ear defenders generally comprise two hard cups that make a seal over the ear. The pressure required to make the seal is exerted by a semi-rigid headband which, depending on the model, can be worn over the head, behind the neck or under the chin. The seals must be replaced if they show signs of degradation caused by mechanical abuse, or, more likely, the effects of skin salts and acids which make the plastic harden. Anything that interferes with the seal – such as long hair, jewellery or spectacles – can render the protection ineffective.
- Insert disposable or reusable ear plugs are worn in the ear canal, effectively sealing the entrance to the ear. Some have an interconnecting cord or head neckband.
- Pre-moulded ear protectors are usually made from soft silicon rubber or plastic.
- Semi-inserts are also generally made of silicone rubber or plastic. They are attached to a headband which exerts a force on the plug to keep it in position.
Before specifying hearing protection, try to reduce the number of people working in noisy areas, or the time they have to spend in these areas.
To select a protector you should ask:
– Is the performance attenuation sufficient to cut the noise dosage to permissible levels?
– Is the protector comfortable enough to wear for long periods?
– Does it carry a mark of quality assurance?
However, remember that hearing protection will only be effective if people know how to use it, so training is essential.
Noise by numbers
We asked 271 factory managers and directors whether they offer their employees hearing protection equipment such as ear plugs or ear defenders.
The vast majority (98.5%) do. However, 14% offer no training in the use of this equipment, a worrying omission since using safety equipment ineffectively is worse than useless because it offers a false sense of security.
One factory manager offered this advice: “Sometimes it is very difficult to police the use of PPE in relation to hearing protection. The key is to involve the wearer from day one. Industrial vacuums were introduced into a manufacturing environment that I once worked in. The vacuums were loud and cumbersome when in operation and it was necessary to build a soundproof booth around them and make the wearing of ear defenders in the area compulsory.
“We purchased ear defenders that would fit under their hard hats. The operators felt they were uncomfortable, and I would often enter the area and have to instruct operators to put them back on. We took the decision to involve employees when selecting PPE as it would allow them to feel they were having their voices heard and selecting PPE that was fit for purpose.”
Other findings of our straw poll include:
Does your company use engineering measures such as machine enclosures, silencers, and/or vibration isolation to reduce noise exposure?
- Yes 79.1%
- No 20.9%
Has your company ever conducted a noise audit/assessment?
- Yes 91.8%
- No or don’t know 8.2%
Does your company offer its employees hearing tests?
- Yes 77%
- No 23%
