We offer two methods for assessing the risk of damage from vibrating power tools. The HAVi monitors the time that the tool is vibrating and this, along with the known vibration figures for the tool, is used to calculate the worker's exposure. The second option is to use a meter like the VEXO to measure the tool's vibration directly.
The vibration from hand-held power tools can be transmitted to the hands and arms causing damage to the blood vessels, nerves and joints. The damage, referred to as HAVS, is permanent but avoidable.
The early signs of exposure to vibration are tingling and numbness in the fingers, followed by a loss of strength in the hands and inability to grip. Continued use of vibrating equipment results in this numbness and weakness becoming permanent. More severe symptoms include blanching of the fingers, often referred to as "vibration white finger".
The Control of Vibration at Work Regulations 2005 are in place to protect workers from exposure to excessive vibration. The HSE provide a handy pocket guide called Hand Arm Vibration, A Brief Guide as well as the full Hand Arm Vibration Guidelines.
The type of equipment that can cause significant levels of vibration are:
A person's exposure to vibration must be controlled by first reducing the vibration that is transmitted to the hand (selecting tools with lower vibration magnitude and maintaining the tool). The overall exposure to vibration can also be controlled by reducing the length of time that the worker is exposed to it.
Regulations vary in different parts of the world, so please check your local regulations for hand arm vibration control.
For example, the UK regulations set two vibration action levels:
EAV - Exposure Action Value
ELV - Exposure Limit Value