Purpose of the guideline is to provide a uniform procedure for assessing the effect on the human being of mechanical whole-body vibration and also to give general instructions on determining the assessment variables. On the basis of the physical data of vibration measurements and taking different frequency-dependent effects into consideration, the root-mean-square value aw of the frequency-weighted accelation aw(t) is formed as a variable characterizing vibration exposure. When the exposure duration T is included it becomes poxxible to estimate restrictions on well-being, performance and the risk of health damage. A knowledge of aw in conjunction with the exposure duration T is thus a necessary condition of formulating measures to avoid or limit the impairments mentioned.