The EC vibration Directive

Employers whose workers are exposed to vibration at work will soon have to comply with stricter standards of control. Chris Dyer reports.

Drivers and operators of vehicles and users of powered tools at risk from vibration exposure should receive enhanced protection from the new EC physical agents (vibration) Directive.1

The Council of Ministers adopted the Directive on 21 May 2002 and it will come into force in June or July 2002 when the text is published in the Official Journal of the European Communities. The HSE is beginning informal consultations with trade unions and other groups on implementation; formal consultation is planned for summer 2003 and will cover draft Regulations and guidance.

Hand-arm vibration (HAV) from the use of hand-held power tools (eg angle grinders), hand-fed machinery (eg pedestal grinders) and hand-guided machinery (eg mowers) causes significant ill health, including painful and disabling disorders of the blood vessels, nerves, joints and muscles of the hands and arms. These conditions are collectively known as hand-arm vibration syndrome and include vibration white finger - impaired blood circulation and blanching of affected fingers and parts of the hand. Whole-body vibration (WBV) comes from riding in vehicles, particularly over rough terrain, and is a factor in back pain and injury.

The UK welcomes the Directive, which is a compromise reached under the "conciliation procedure" between the Council of Ministers' original proposals and amendments put forward by the European Parliament (Physical agents: Ministers place vibration proposals on shaky ground). The HSE considers the requirements to be broadly proportionate to the risks of exposure and that compliance should result in significant improvements in health, and in particular the virtual elimination of HAV syndrome.

The new values

Hazard to health is usually assessed from the average (root-mean-square, or rms) acceleration level. Measurement gives the "frequency-weighted acceleration" in m/s2. Current HSE guidance (HSG88)2 on HAV recommends programmes of preventive measures and health surveillance when workers' exposure regularly exceeds the action level of 2.8 m/s2 A(8)(8-hour average), measured using the old standard BS 6842:1987 (now withdrawn). This standard measured vibration in three directions (up and down, front to back and side to side), but exposure was calculated from the magnitude of vibration in the dominant axis.

The vibration Directive sets two numerical standards for HAV:

  • it defines an exposure action value (EAV) of 2.5 m/s2 A(8); and

  • an exposure limit value (ELV) of 5 m/s2 A(8).

    These quantities are based on the vibration total value, a vibration magnitude obtained from measurements in three directions, using the method defined in the new standard BS EN ISO 5349-1:2001. The vibration total value is greater than the dominant axis magnitude by a factor of between 1.0 and 1.7, but is about 1.4 on average. This means that the current action level of 2.8 m/s2 A(8) is approximately 4 m/s2 A(8) expressed as a vibration total value and lies between the new exposure action and limit values (see box).

    The WBV exposure values are:

  • EAV: 0.5 m/s2 A(8); and

  • ELV: 1.15 m/s2 A(8).

    These values are for vibration measured in a single direction (the direction with the highest vibration). The European Parliament had voted to reduce the ELV still further to 0.8m/s2 A(8). But this provoked an angry response from employers' organisations; the final text allows a minor concession to the MEPs on EAVs, but not the ELV.

    Member states may choose to specify WBV action and limit values as a vibration dose value (VDV), in which case:

  • EAV: 21 m/s1.75 A(8); and

  • ELV: 9.1 m/s1.75 A(8).

    The HSE is considering setting the whole body vibration exposure limit value as a VDV, as this is likely to provide a greater degree of protection to hazardous exposures. Vibration dose value takes more account of shocks and jolts than A(8)-based rms acceleration, and is therefore thought to be more representative of risks to health where the vibration contains shocks. An estimated VDV can be calculated from rms acceleration and exposure time, except where there are shocks, in which case it has to be measured directly.

    The Directive's main requirements

  • The Directive requires employers, where there is likely to be a risk from exposure to vibration, to assess exposure levels by observing specific working practices and reference to information on the probable magnitude of the vibration corresponding to the equipment and its conditions of use, including information provided by the manufacturer of the equipment. This operation is distinguished from measurement, which requires the use of specific apparatus and appropriate methodology, and may be necessary depending on the results of the initial assessment (see box below).

  • When exposure reaches the exposure action value, the employer must implement measures to reduce exposure to a minimum and provide appropriate health surveillance;

  • Workers must not be exposed above the exposure limit value. If, despite the measures taken by the employer to comply with this Directive, the ELV is exceeded, the employer must take immediate action to reduce exposure below the ELV. It must identify the reasons why the exposure limit value has been exceeded, and amend the protection and prevention measures to prevent it being exceeded again.

    Member states have three years in which to implement the Directive; limit values will apply to new equipment three years after Regulations come into force. The Directive also contains provisions for Member states to introduce transitional periods: five years after Regulations come into force for equipment already in use and nine years for agriculture and forestry equipment. Consultation is likely to cover the issue of transitional periods, but it is not certain that the UK will include transitional periods in its implementing legislation.

    The HSE believes that employers' compliance with the Directive's requirements will be helped by further information and advice. Manufacturers of equipment are being encouraged by the HSE to provide as much information as they can on the management of vibration health risks presented by use of their equipment, and to comply fully with the requirements of the Supply of Machinery (Safety) Regulations 1992.


    Vibration magnitudes and durations

    A person's daily vibration exposure (or A(8) value) is obtained from the vibration magnitude and the exposure duration. The HSE's guidance on hand-arm vibration (HSG88) gives a nomogram for obtaining A(8) values graphically, but calculations are required where the worker's daily exposure comes from a number of sources (different tools or processes). The HSE's website1 provides an electronic calculator that allows users to enter the vibration magnitude and exposure duration for up to six sources and obtain the partial vibration exposures and combine them to get the overall A(8) value.


    Risk assessment and reduction

    When carrying out the risk assessment, employers must pay particular attention to:

  • the level, type and duration of exposure, including intermittent vibration or repeated shocks;

  • the ELVs and the EAVs laid down in the Directive;

  • any effects concerning the health and safety of workers who are particularly sensitive to risk;

  • any indirect effects on worker safety resulting from interactions between mechanical vibration and the workplace or other work equipment;

  • information provided by the manufacturers of work equipment in accordance with the relevant Community Directives;

  • the existence of replacement equipment designed to reduce the levels of exposure to mechanical vibration;

  • the extension of exposure to whole-body vibration beyond normal working hours under the employer's responsibility;

  • specific working conditions such as low temperatures; and

  • appropriate information obtained from health surveillance, including published information.

    Once the exposure action values are exceeded, the employer must establish and implement a programme of technical and/or organisational measures intended to reduce to a minimum exposure to mechanical vibration and the attendant risks, taking into account in particular:

  • other working methods that require less exposure to mechanical vibration;

  • the choice of appropriate work equipment of appropriate ergonomic design and, taking account of the work to be done, producing the least possible vibration;

  • the provision of auxiliary equipment that reduces the risk of injuries caused by vibration, such as seats that effectively reduce whole-body vibration and handles that reduce the vibration transmitted to the hand-arm system;

  • maintenance programmes for work equipment, the workplace and workplace systems;

  • the design and layout of workplaces and work stations;

  • adequate information and training to instruct workers to use work equipment correctly and safely in order to reduce their exposure to mechanical vibration to a minimum;

  • limitation of the duration and intensity of the exposure;

  • appropriate work schedules with adequate rest periods; and

  • the provision of clothing to protect exposed workers from cold and damp.

    • 1"Directive 2002/***/EC of the European Parliament and of the Council on the minimum health and safety requirements regarding the exposure of workers to the risks arising from physical agents (vibration) (sixteenth individual Directive within the meaning of Article 16(1) of Directive 89/391/EEC)".

    2"Hand-arm vibration", HSG88, HSE Books, ISBN 0717607437, £7.50.