Should multiple machines or vehicles be assessed separately for whole body vibration (WBV)?

Ideally, yes — because WBV exposure can vary quite a bit between machines, even if they appear similar.

Differences in age, tyre condition, maintenance status, seat suspension, and how the equipment is used can all influence vibration levels. Two forklifts from the same manufacturer may produce noticeably different exposures depending on working surface or operator behaviour.

Where workers rotate between machines, this should also be taken into account during exposure calculations.

Assessing representative machines is sometimes acceptable — but assuming that one result applies to all equipment can lead to underestimating risk.