<P> The Control of Vibration at Work Regulations 2005, created under the Health and Safety at Work etc . Act 1974 . is the legislation in the UK that governs exposure to vibration and assists with preventing HAVS occurring . </P> <P> Good practice in industrial health and safety management requires that worker vibration exposure is assessed in terms of acceleration amplitude and duration . Using a tool that vibrates slightly for a long time can be as damaging as using a heavily vibrating tool for a short time . The duration of use of the tool is measured as trigger time, the period when the worker actually has their finger on the trigger to make the tool run, and is typically quoted in hours per day . Vibration amplitude is quoted in metres per second squared, and is measured by an accelerometer on the tool or given by the manufacturer . Amplitudes can vary significantly with tool design, condition and style of use, even for the same type of tool . </P> <P> In the UK, Health and Safety Executive gives the example of a hammer drill which can vary from 6m / s2 to 25m / s2 . HSE publishes a list of typically observed vibration levels for various tools, and graphs of how long each day a worker can be exposed to particular vibration levels . This makes managing the risk relatively straightforward . Tools are given an Exposure Action Value (EAV, the time which a tool can be used before action needs to be taken to reduce vibration exposure) and an Exposure Limit Value (ELV, the time after which a tool may not be used). </P> <P> In the United States, the National Institute for Occupational Safety and Health published a similar database where values for sound power and vibrations for commonly found tools from large commercial vendors in the United States were surveyed . Further testing is underway for more and newer tools . </P>

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