Vibration

The risk of exposure to vibration at work in the University must be controlled in accordance with The Control of Vibration at Work Regulations, 2005.

The main areas of concern to the University are principally hand-arm vibration and to a lesser extent whole body vibration. The regulations introduce action and limit values for both hand-arm and whole-body vibration.

Hand Arm-Vibration:

Hand Arm-Vibration (HAV) is vibration transmitted from work processes into the worker's hands and arms. It can be caused by hand held power tools, hand guided equipment such as lawn mowers, or by holding materials being processed by machines such as grinders.

Around five million employees in Great Britain are exposed to hand-arm vibration in the workplace. Two million of these workers are exposed to levels of vibration where there are clear risks of developing disease. This is most likely to occur when contact with a vibrating tool or work process is a regular prolonged occurrence, occasional exposure is unlikely to cause ill-health.

Regular prolonged exposure can cause conditions such as Hand Arm Vibration Syndrome (HAVS), which includes vibration white finger, and carpal tunnel syndrome. Both are serious conditions, however vibration white finger may result in irreversible debilitating damage to the fingers.

Identifying the symptoms early is crucial to preventing adverse health effects from becoming serious, these symptoms may include;

• Tingling, numbness and 'pins and needles' in the fingers
• Losing the sense of touch
• Loss of strength in the hands
• Fingers going white (blanching) and becoming red and painful on recovery, particularly in the cold and wet (probably only at the finger tips initially, but spreading with continued exposure).

These symptoms can take months or even years to appear and are likely to progressively get worse if exposure continues and may become permanent.

The long term effects can include:

• Pain, distress and sleep disturbance
• Loss of ability to work effectively due to:
  • Inability to do fine work or tasks (eg. fastening buttons!)
  • Reduced ability to work in cold and damp conditions
  • Reduced grip strength
• In severe cases skin ulcers and even gangrene

The Control of Vibration at Work Regulations, 2005: as applied to HAV

The Regulations introduce a:

• Daily exposure action value of 2.5 m/s² A(8) at which level employers should introduce a programme of technical and organisational measures to reduce exposure to HAV.
• Daily exposure limit value of 5 m/s² A(8) which should not be exceeded since it represents a high risk of HAVS.

Note: 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. The exposure limit value may be exceeded so long as all other requirements of the regulations have been met and all reasonably practicable actions have been taken to reduce the exposure as much as you can.

The Regulations require that you must:

• Assess the hand arm vibration risk to workers
• Decide if they are likely to be exposed above the daily exposure action value and if they are to:
  • Introduce a programme of controls to reduce the exposure to as low a level as is reasonably practicable
  • Provide health surveillance (via the University's Occupational Health Service) for those employees who continue to be exposed above the action value, or otherwise continue to be at risk
• Decide if they are likely to be exposed above the daily exposure limit value and if they are take immediate action to reduce their exposure below the limit value. In the short term this can be achieved by reducing the time spent working with the source of the vibration
• Provide information instruction and training to those who may be exposed
• Keep a written record of the risk assessment and review it regularly
• Keep health records for employees under health surveillance.

Measuring the vibration displacement, m/s² A(8), of a particular tool is not straightforward and requires specialist equipment and training. This is not necessary in most cases in the University. Risk assessment can be based on data supplied directly from the manufacturer* or from one of the online databases including:

• HSE
• OPERC HAVTEC (free to use, registration required)

The OPERC website lists a range of tools by make and model, giving the measured vibration values and the 'maximum allowed trigger time' before reaching the action and limit values for particular named tasks with that tool.

Note: Data from the OPERC website indicate that for the same hammer drill the vibration value drilling concrete with a 7 mm masonry drill bit is 8.7 m/s² rising to 19.3 m/s² with a 18 mm masonry drill bit. This reduces the maximum 'trigger time' to reach the daily exposure action value from 40 to 8 minutes!

Some typical vibration levels (m/s²) supplied by the HSE for common tools are:

The HSE advise that if the only information available to you is the vibration emission declared in the manufacturers hand book, it may be safer to double this figure before using it to estimate daily dose.

Note: The 'trigger time' is the time that the tool is actually in use and generating vibrations. In order to carry out a vibration exposure assessment the trigger time must be recorded accurately, preferably by observation. i.e. If a hand held hammer drill is "used all morning" it is very unlikely that an individual actually held it whilst it was drilling for 4 hours without releasing the trigger, carrying out other work, or taking a rest.

The calculation of exposure to vibration becomes more complex when more than one tool generating vibration is used during the day and the HSE advises the use of their 'exposure points system'. This allocates points to each vibration exposure which can be added together and compared against the point values allocated for the exposure action and limit values. Further information on this system is available on the HSE web site and in HSE publications (see below).

Controlling Hand-Arm Vibration Exposure:

Limiting the time an employee is exposed to vibration is the quickest, simplest and most immediate way to comply with the Regulations.

However this should be followed up with further control measures to reduce vibration exposure to the lowest reasonably practical level, ie:

• Use alternative working methods that eliminate or reduce exposure to vibration
  • Plan work to introduce alternative work and rest breaks
  • Introduce team work and rotas to limit individual exposure.
• Mechanise or automate the work
• Use efficient machinery and working practices to minimise exposure times
• Use the lowest vibration tools suitable for the task, limiting the use of high vibration tools wherever possible.
• Purchase low vibration equipment whenever possible
• Ensure tools are maintained in accordance with manufacturer's instructions and replace worn or damaged drills, chisels or discs etc.
• Use jigs and suspension systems to reduce the need to tightly grip heavy tools
• Provide protective clothing to keep employees warm and dry, this encourages blood circulation and helps to prevent vibration white finger
  • Gloves, including so-called 'anti-vibration gloves', keep hands warm but in practice do NOT protect against vibration itself

Monitoring Exposure by Providing Health Surveillance:

You must provide health surveillance through the University's Occupational Health Service for all employees who, despite the actions to control exposure are likely to be regularly exposed above the exposure action value or are considered to be at risk for any other reason. This is particularly important for employees with a history of exposure to vibration, who may already be suffering symptoms or have early stage, but so far non-symptomatic, damage and are therefore at increased risk.

Note: If an employee is diagnosed in writing by a doctor to be suffering from work related HAVS or carpel tunnel syndrome the University's Occupational Health Service are responsible for reporting it to the HSE under the Reporting of Injuries, Diseases and Dangerous Occurrences Regulations (RIDDOR).

Whole Body Vibration:

Drivers of some mobile machines, including certain tractors, ride-on mowers, fork lift trucks and earth-moving machinery, may be exposed to whole-body vibration (WBV), through the seat or their feet. This vibration can cause back pain or make a pre-existing back condition worse. However, other work factors, such as posture, workplace ergonomics and heavy lifting, are also known to contribute to back problems for drivers and the relative importance of WBV is not clear at present. It is generally accepted that for healthy people most workplace exposure to WBV on its own is unlikely to cause back pain, however older people, those with previous back or neck pain, young people and pregnant women are more likely to be at risk.

The Control of Vibration at Work Regulations, 2005: as applied to WBV

The Regulations introduce a:

• Daily exposure action value of 0.5 m/s² A(8) at which level employers should introduce a programme of technical and organisational measures to reduce exposure.
• Daily exposure limit value of 1.15 m/s² A(8) which should not be exceeded.

Note: The regulations also allow a transitional period for whole-body vibration until 2010 to allow work activities, where the use of older tools and machinery cannot keep exposures below the exposure limit value, to continue in certain circumstances. There is also a further transitional period to 2014 for Agriculture and Forestry sectors.

By complying with The Control of Vibration at Work Regulations and following HSE guidance, it should be possible to reduce the risks from whole-body vibration.

The Regulations require that you must:

• Assess the whole body vibration risk to workers
• Decide if they are likely to be exposed above the daily exposure action value and if they are introduce controls to reduce the exposure so far as reasonably practicable
• Decide if they are likely to be exposed above the daily exposure limit value and if they are take immediate action to reduce their exposure below the limit value. In the short term this can be achieved by reducing the time spent working with the source of the vibration
• Provide information instruction and training to those who may be exposed
• Keep a written record of the risk assessment and review it regularly.

Note: Measuring the vibration displacement, m/s² A(8), of a particular piece of equipment is not straightforward and generally will not be necessary in most cases in the University. The risk assessment can be based on data supplied directly from the manufacturer or from one of the databases available online including from: the HSE.

Controlling Whole Body Vibration Exposure:

There are simple, non-technical and common sense measures which can then be introduced to control and thereby reduce exposure to WBV including:

• Select / purchase equipment with appropriate any-vibration devices
• Fit anti-vibration devices, where appropriate, to existing equipment, after consulting both the manufacturers of the original equipment and the devices with respect to suitability
• Adjusting seat position and where available suspension settings to minimise vibration and maximise good posture
• Adjust the vehicle speed to suit conditions and drive vehicles smoothly
• Avoid rough terrain or poorly maintained surfaces
• Maintain vehicle suspension, seating and tyres
• Introduce work schedules that avoid long exposure periods and build in alternative work or rest breaks
• Avoid prolonged exposure of older employee, people with existing back or neck problems, young people or pregnant women
• If risk is high then carry out health monitoring in consultation with the University's Occupational Health Service
• Provide information instruction and training to employees on the risks and the procedures to be followed to minimise those risks.

Further Reading:

HSE publications

• Hand-Arm Vibration, Guidance on Regulations, L140, ISBN 0 7176 6125 3
• Control the Risks from Hand-Arm Vibration, INDG 175 (rev2), ISBN 0 7176 6117 2
• Control of Back Pain Risks from Whole Body Vibration, INDG 242 (rev1), ISBN 0 7176 6119 9