A study was conducted to quantify whole-body Vibration (WBV) emission and likely operator daily exposure levels associated with the normal operation of 13 different types of machine used in the construction, earthmoving, quarrying and mining industries. WBV measurements were made on 16 working machines, encompassing (if possible) a half-day (3-4 hours) of commercial activity, to provide representative samples of WBV time-histories. Frequency analysis of the vibration data and direct observation provided information on the potential for reducing operator WBV exposure in each instance, by appropriate selection and use of suspended seats.

Machine WBV emission and operator daily exposure levels fell into three broad categories:​

• Low WBV exposure levels, not exceeding the Exposure Action Value (EAV) in a typical working day;​
• Moderate WBV exposure levels, above the EAV, but not approaching the Exposure Limit Value (ELV) in a typical working day;​
• Higher levels of WBV, potentially approaching the ELV in a typical working day.

Suspended seats, if appropriately selected and properly maintained, may provide useful reduction of vertical (Z-axis) whole-body vibration on machines such as Fork Lift Trucks, Site Dumpers and Bulldozers.

The most important factors in controlling/reducing operator exposure to WBV are likely to be adequate information and appropriate training in ‘Best Practice’. Maintenance of haul roads and/or other operating surfaces can help to reduce machine WBV emission/operator exposure levels, but only if vehicle travel speeds are also controlled. Care is required in measuring operator WBV exposure levels in instances when the operator spends a proportion of the measurement period absent from the vehicle seat.

This report and the work it describes were funded by the Health and Safety Executive (HSE). Its contents, including any opinions and/or conclusions expressed, are those of the authors alone and do not necessarily reflect HSE policy.