When the vibration levels have been reduced so far as is reasonably practicable, further reduction in exposure can only be achieved by limiting the time for which employees are exposed to vibration. This is sometimes necessary to keep exposure below the limit value. It is often helpful to use job rotation (sharing the work and the vibration exposure between several people).
Where an employee has a single source of vibration (just one tool or process) it is fairly straightforward to establish a maximum daily exposure duration before, for example, the exposure action or limit value is reached.
If an employee uses two or more tools or processes, this is more complex, but HSE’s exposure points system can be useful to help your supervisors manage your employees’ exposures. You can use the exposure ‘ready-reckoner’ to estimate the number of 'exposure points ' per hour for each tool or process. By setting a daily limit on the exposure points for each operator, you can control the daily exposure, even if several different tools or processes contribute to the exposure.
Make sure you maintain an effective level of supervision after introducing new working patterns. It is not uncommon for ‘old’ work practices to reappear, which can defeat the object of the exercise. Devices are now available which cut off the power supply to pneumatic or electric tools after a specified total operating time. These can help you to control your employees’ vibration exposure time, but will still need to be managed carefully.
It is believed that employees who are paid by piecework or payment-by-results schemes can be at increased risk. Not only is the period of exposure likely to be intensive and with fewer breaks, but also the rapid pace of work can result in employees applying higher levels of force to the task, increasing the risk of vibration-related ill health and musculoskeletal problems.