What is HAV Syndrome

Hand Arm Vibration (HAV) Syndrome is the permanent, but preventable, condition associated with repeated use of hand-held power tools at work. HAV exposure can result in:

Nerve damage – a tingling and numbness leading to a loss of touch in the fingers.
Vascular damage – episodic attacks due to damage to blood vessels and circulation (also known as “vibration white finger” or ‘Secondary Raynards’).
Musculo-skeletal damage – discomfort, pain and loss of grip strength in the hand.

Source: HSE

Workers’ exposure to hand-arm vibration is regulated by the Control of Vibration at Work Regulations (CVAWR). The risk from the exposure to vibration must be either eliminated at source or, where this is not reasonably practicable, reduced to as low as is reasonably practicable (ALARP).

If the Exposure Action Value (EAV) of 2.5 m.s -2 A(8) is likely to be reached or exceeded, the employer shall reduce exposure to ALARP by establishing and implementing a programme of organisational and technical measures, appropriate to the activity. The Exposure Limit Value (ELV) of 5 m.s -2 A(8) is the maximum amount of vibration an employee may be exposed to, on any single day.

The CNAWR require a HAV risk assessment to be undertaken which can include the measurement of the vibration magnitude from different hand-held power tools.

HAV measurement s is undertaken by mounting an accelerometer on the handle/s of the tool (in accordance with BS 5349-2) to measure the root mean square (rms) vibration in the 3 axes.

The accelerometer is connected to a HAV monitoring instrument conforming to BS 8041.

The frequency-weighted rms acceleration values of the 3 axes are combined to give an overall frequency-weighted vibration magnitude known as the vibration total value or ‘vector sum’.

Dust2Noise can then calculate the daily exposure (A(8)) using the formula for daily vibration exposure in BS 5349-1 for each worker, based on their tool use and duration of exposure.


These daily exposures can then be compared with the EAV and ELV in the CNAWRs.


If you would like Dust2Noise to conduct measurement of HAV from use of hand-held power tools in your workplace and be provided with detailed information regarding worker exposure and risk of HAVS – please complete the enquiry box below.

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