Wednesday, November 08, 2006

Vibrations

There are two main concerns regarding vibration

1. Whole body vibration
2. Hand arm vibration

Whole-body vibration is shaking or jolting of the human body through a supporting surface (usually a seat or the floor), for example when driving or riding on a vehicle along an unmade road, operating earthmoving machines or standing on a structure attached to a large, powerful, fixed machine which is impacting or vibrating. It can cause back pain, often by aggravating a previous problem.

Hand-arm vibration can be caused by operating hand-held power tools (e.g. road breakers), hand-guided equipment (e.g. powered lawnmowers) or by holding materials being processed by machines (e.g. using pedestal grinders).

Regular and frequent exposure to hand-arm vibration can lead to permanent health effects (occasional exposure is unlikely to cause ill health). Symptoms include
* Tingling and numbness in the fingers;
* Not being able to feel things properly;
* Loss of strength in the hands;
* The fingers going white (blanching) and becoming red and painful on recovery
(particularly in the cold and wet, and probably only in the tips at first).
* Continued exposure can mean people cannot use their fingers properly, especially in cold conditions.

The Control of Vibration at Work Regulations require employers to:
* Assess the vibration risk to employees;
* Decide if they are likely to be exposed above the daily exposure action value (EAV), and if so introduce a programme of controls to eliminate risk, or reduce exposure to as low; and provide health surveillance
* Decide if they are likely to be exposed above the daily exposure limit value (ELV) and if they are take immediate action to reduce their exposure below the limit value;
* Provide information and training to employees on health risks and the actions you are taking to control those risks;
* Consult trade union safety representative or employee representative on your proposals to control risk and to provide health surveillance;
* Keep a record of risk assessment and control actions;
* Keep health records for employees under health surveillance;
* Review and update your risk assessment regularly.

The exposure action value (EAV) is a daily amount of vibration exposure above which employers are required to take action to control exposure. For hand-arm vibration the EAV is a daily exposure of 2.5 m/s2 A(8) and for whole body vibration 0.5 m/s2 A(8)

The exposure limit value (ELV) is the maximum amount of vibration an employee may be exposed to on any single day. For hand-arm vibration the ELV is a daily exposure of 5 m/s2 A(8) and for whole body vibration 1.15 m/s2 A(8)

Whole body vibration Reference

Hand- arm vibration Reference

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