The term vibrating tools means all kind of handheld tools powered by an energy source. Some examples of tools with different energy sources are, electrical-, air-, gas/petrol-, ultrasonic-or water-powered tools. The list of vibrating tools can be almost infinite.

According to the regulations, all employers must undertake a Risk Assessment including assessment of the A(8) vibration exposure. The regulation lists two different possibilities:

1. Measure the A(8) exposures in the workplace according to standard ISO 5349.
2. A theoretical estimation based on the declared emission level (acceleration level) for each Tool.

Our recommendation is to utilise method 2 for the Risk Assessment. Then, if necessary, utilise method 1 only on the suspected "worst case tools".

Regardless of selected method for the Risk Assessment, it should also be mentioned that high-speed tools or instruments such as dental drills, ultrasonic instruments will provide an A(8) exposure that is well below the Action Value (2.5 m/s2) for hand-arm vibration. Still these tools are potentially very harmful and thus can cause vibration damages.

Here you can calculate how long you can work with a tool.

1. Measure the A(8) exposure according to ISO 5349
The ISO 5349 standard specifies how to measure and assess the A(8) exposure by measuring on a tool used "in real time”. The standard requires an attached sensor (glued) on a Tool. The emission level is then measured with a measuring device while the Tools is powered on and in use

In practice, this method has proved to be both "difficult" and imprecise due to a variety of external factors affecting the measurement results. This includes ,how hard you hold the tool, hand size, tool wear, etc.

It is also difficult to reproduce the results from time to time even if measured with the same person and set up. Furthermore, in many workplaces, it is common to use a large number of tools in one day. Measuring up all these can take both long and cost a lot of money.
 

2. Theoretical estimation based on declared levels.
Within the EU, all tool manufacturers must declare the vibration levels on their tools according to a given standard (EN 60745, ISO 28 927 or equivalent).

Thus, for this option of Risk Assessment, you can either look in the tool's data sheet, or look in a national database for example at Umeå University.

However, note that new rules for this declaration are valid from December 2009.  The new rules require that a tool shall be declared considering three acceleration directions instead of one direction, as stated in the older standard.

The revision of the measurement standard has led to that the same tool (in many cases) has got a higher declared vibration levels compare with the older standard. In extreme cases up to three times higher. On the other hand, some tools have got lower values due to changes in the revised test set up.

For Employers with Risk Assessment based on the older vibration data, it may be wise to do a new Risk Assessment based on latest declared vibration levels.

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For those interested, you can read more about vibrations here
http://www9.umu.se/phmed/envmed/forskning/vibration/ (page in Swedish)