Vibration Calculation & Exposure

HSE regulations state:suitable health surveillance should be undertaken where risk assessment indicates a risk to workers health.”

Good practice within industrial health and safety management indicates that in order to survey the risk to workers effectively, acceleration magnitude and duration should be assessed in relation to vibration exposure. Commonly health surveillance simply detects and highlights those operatives who have contracted HAVS. However continuous monitoring can quantify risk, allowing for timely data analysis, which can predict and prevent contraction of HAVS.

Fact: There is no cure for HAVS

In order to reduce the risk to your employees prevention is better than detection.



The HSE regulations provide all tools with an EAV and ELV for hand arm vibration (HAV) and whole body vibration (WBV). Employers are then expected to make an assessment of exposure that identifies the risk of either value being exceeded.


Exposure action value– the time a tool can be used on a daily basis before action must be taken to reduce exposure (EAV) 2.5m/s2 A(8) is equal to 100 points.

Exposure Limit Value– the maximum amount of vibration an employee can be exposed to in a day (ELV) 5m/s2 A(8) is equal to 400 points.

The table shows the EAV and ELV exposure limits for both hand arm vibration and whole body vibration.


Using a vibrating tool with a low magnitude for an extended period of time can be as damaging as using a tool with a high magnitude for a short period of time. The table below can be used to manually calculate daily vibration exposure level in points.


Vibration Magnitude

The vibration magnitude level of a tool is provided my the manufacturer or can
be gained from live/field testing of the tool. Magnitude can vary from tool
design, condition and the style of use.

Magnitude is quoted in =

metres per second square


Exposure time

In order to gain accurate results for vibration surveillance and monitoring, duration must be measured as TRIGGER TIME.

(The period of time when the operator actually has their finger on the trigger, making the tool active.)

Duration is quoted in = Hours Per Day


Curotec has a team of experienced health and safety consultants on hand to explain the further implications and risks associated with Hand Arm and Whole Body Vibration, in order for you to protect your employees and protect your business.

Curotec Team Ltd are vibration management specialists, with a team of trained Health and Safety Consultants, Technical Installation Managers and Support Advisors aiding business’s to comply with the ‘Control of vibration at work regulations (2005)’.