Noise and Vibration - Shake, rattle and hum01 August 2005

All employers, operators and users of equipment that causes noise and/or vibration need to take very serious notice of the new regulations relating to vibration that come into force on July 6th 2005 and the corresponding noise regulations that must be in place by February 15th 2006

Some regulations stemming from European Union Directives are fairly toothless. For example, it is hard to think of anyone who has been prosecuted for equipment failing the requirements of the EMC Directive. And nobody seems to know what the WEEE directive, supposed to be implemented by September 2005, will actually mean in practice, if it ever does mean anything much more than good intentions.
The same, however, is far from true of the noise and vibration regulations, for several reasons.

First, prolonged exposures to high levels of noise and vibration cause severe disabilities - leading to an inability to work in one case and deafness in the other. Secondly, noise and vibration can easily be measured using hand-held instruments so that HSE inspectors can come in, make their measurements and quickly find out exactly what they want to know about the safety or otherwise of equipment. Thirdly, no-win, no-fee lawyers are out there, hungry for business, so that failure to conform, resulting in disability, is liable to be extremely expensive.

In addition, excessive noise and vibration reduces efficiency. So while the regulations are concerned with reducing levels hazardous to health, employers should also consider the possible benefits to be obtained by reducing levels to those at which people are able to work more comfortably and efficiently.

Fortunately, both hazards can, in most cases, be easily reduced by taking fairly simple, and in many instances quite inexpensive, measures.

Finger on the problem

Primary Reynaud's phenomenon, finger blanching, was first identified by Dr Maurice Raynaud in 1862. Primary Raynaud's phenomenon is not caused by vibration, but is inherited. However, Secondary Raynaud's phenomenon, vibration white finger or VWF, was first linked to the use of pneumatic tools as long ago as 1911.

It was not until the Taylor-Pelmear scale was published in 1975 that the condition could be assessed in a consistent way. And it was only from 1985 onwards that there was a requirement for employers to report VWF under the Reporting of Injuries, Diseases and Dangerous Occurrences Regulations. In 1992, the Supply of Machinery Safety Regulations were introduced, which required that risks resulting from mechanical vibrations should be reduced to the lowest levels, and required the provision of vibration data and advice to purchasers.

In 1997, the High Court awarded £127,000 to seven miners for VWF, with 12,500 more cases in the pipeline. According to the HSE, interim results from current research indicate that the number of people exposed to high levels of vibration in the UK may exceed 1 million. European Community Directive 2002/44/EC was published in the Official Journal of the European Communities in 2002.

Risky business

Risks from vibration are divided into two categories, Hand Arm Vibration (HAV) and Whole Body Vibration (WBV). HAV risks are associated with all industries that involve using hand-held tools or machines that transmit vibration into the hands. WBV risks are associated with back pain along with other factors, such as poor posture and heavy lifting. WBV in industry usually results from driving commercial and industrial vehicles, and construction equipment.

It is assumed that damage results from a combination of vibration levels and the length of time exposed to them during each working day. The mathematical formulae used to calculate risk all have square roots in them, which means that a doubled high level of vibration should only be endured for one quarter the time.

The Exposure Action Value (EAV) - above which employers are required to take action - is a daily exposure of 2.5m/s2. The Exposure Limit Value (ELV) is the maximum amount of vibration the employee may be exposed to on any single day and is set at 5m/s2. The regulations allow a transitional period for the limit value until July 2010. This only applies to work equipment already in use before July 2007. 5m/s2 is reckoned to be about the level produced by working with a modern, low vibration-level road breaker. Road breakers can produce up to four times this level of vibration and hammer-type scabblers up to eight times. Demolition hammers are in the range 8m/s2 to 25m/s2. Hammer drills come out in the range 6m/s2 to 25m/s2.

For those who are put off by mathematics, ready reckoner tables to calculate permissible exposures at different vibration levels may be found on the HSE website. For Whole Body Vibration, the EAV is set at 0.5m/s2 daily exposure and the ELV at 1.15m/s2. The regulations again allow a transitional period for the limit value until July 2010, or 2014 for the agricultural and forestry sectors, which only applies to machines or vehicles first supplied to employees before July 2007.

Although many hand-held tools manufactured hitherto produce much higher vibration levels than those specified in the regulations, it is not hard to design out most of the vibration. One of the simplest approaches is to have a mass going in the opposite direction to the work piece at any moment in time, so that the whole delivers a net zero or close to zero reaction force at the operator's hands. Vibration in machines of all kinds is generally something to avoid because, as well as damaging users, it is usually damaging to the machines. In vehicles, operators may need to be given seats with better suspensions, which adds little to the usually not insignificant cost of the vehicles, yet can do much to improve operator comfort and reduce fatigue. And as well as reducing risks to operator health, machines and vehicles that produce low vibrations are also inherently quieter, which is of benefit to everyone.

Risk of deafness is massive

The deafening effects of loud noises have been known since ancient times, and the HSE estimates that over 2 million UK workers are currently at risk from excessive noise. Like some many other risks, safe, acceptable noise levels have tended to be reduced as time has gone by.

At present, the 'First action level', which requires noise assessments to be made by a competent person - and a record of assessments to be kept until a new one is made - is 85dB(A). Moreover, hearing protection is to be provided to all those that ask for it.
The 'Second action level' is set at 90dB(A), which requires employers to reduce exposure as far as is reasonably practicable other than by hearing protection and ensure that all who go into a marked hearing protection zone will use hearing protectors. The peak action level is a maximum pressure of 200 Pa (140dB).

The HSE says that hearing protection should only be considered as a last resort. The cheapest types of earplugs are not usually sufficient, since they rarely fit everyone's ears and may have a tendency to fall out. Claimed sound level reductions are in the range 23dB to 35dB, but our experience is that they are generally not as good as that. Ear muffs give sound level reductions of 23dB to 31dB and offer the advantage that they are more comfortable to wear, while it is also immediately apparent as to whether operators are wearing them or not.

The best earplugs, of course, are custom-made to fit individual users. They cost more, typically £60 and upwards, but in our opinion are definitely worth the extra. In countries such as Germany or Holland, where unions are stronger than in the UK, workers often insist on being supplied with these. And on a different - and more musical - note, we are told that rock musicians generally all rely on them as well.

Sounds of silence

A better approach is to try to reduce the sources of noise. Machines should be enclosed where possible, which also aids cleanliness and safety. Compressed air outlets on tools should be equipped with silencers. Almost everyone prefers to drive in quieter vehicles. Machines that pound their environment may well be damaging the building they are in, as well as worker well-being.
A quiet work place is a safer and more efficient work place. Noise interferes with human activities to varying degrees. Intruding noises, for instance, can cause problems by distracting an individual's attention and by making activities more difficult to perform, especially where high levels of concentration are needed.

The highest noise level that permits relaxed conversation with 100% sentence intelligibility throughout the room is 45dB. People tend to raise their voices when the background noise exceeds 45-50dB. If it is more noisy, speakers and listeners either have to move closer together or expect reduced intelligibility.

Figures produced by the US EPA indicate that two speakers can communicate with 95% intelligibility, with normal voice effort, at a distance of three meters against a steady background noise of 56dB. If the background level increases to 66dB, the speakers either have to move to one metre apart to maintain the same intelligibility or, alternatively, raise their voices appreciably. If they remain three metres apart without raising their voices, speech intelligibility drops considerably.

If it is quiet, workers can hear each other easily, work together efficiently and warn each other of danger. Everyone can think more clearly and what is created is a pleasant - and safer - environment.

Good vibrations from experts

For those who want some real 'horse's mouth' information, the SOE is organising a one-day seminar on 'Noise and Vibration Legislation Uncovered', to be held on September 13th 2005 at Austin Court in Birmingham. Austin Court is right in the town centre, a short walk from New Street Station and various car parks.

The first paper, 'Noise and Vibration: Regulations and Management of Risks', will be given by Tim Ward of the Health and Safety Executive at 10.40 am. This will be followed by 'The Legal Viewpoint', to be given by Ian Toft of Wake Smith Solicitors. Subsequently, Peter Wilson of the Industrial Noise and Vibration Centre will deliver a paper on 'Noise and Vibration at Work - Good Practice Controls'.

In the afternoon, Mike Hewett, noise and vibration division manager at AV Technology, will deliver a paper on 'Noise and Vibration Assessment and Reduction'. This will be followed by 'Whole Body Vibration in Vehicles', to be presented by Miles Pixley of JCB. There will also be papers on 'The Medical Perspective' and 'The Insurance Perspective'.

The cost to attend is £80 + VAT for SOE members, £110 + VAT for non-members and £38 + VAT for retired and student SOE members. All fees include a copy of the presentations, lunch and refreshments. To register, go to www.soe.org.uk and download the registration form or contact Ed Maycock on 020 7630 1111 or ed.maycock@soe.org.uk

Health and Safety Executive
www.hse.gov.uk/vibration
www.hse.gov.uk/noise

SOE

Related Websites
www.hse.gov.uk/noise
www.hse.gov.uk/vibration

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