Whole-Body Human Vibration Exposure

Assessing the Risk of Vibration in the Human Body

Every day, human beings interact with some sort of machinery, making contact with vibration inevitable. Unfortunately, continuous exposure to mechanical vibration can lead to serious injury.

Understanding Whole-Body Vibration

Whole-body vibration (WBV) is the vibration transmitted through the seat or feet of a worker while operating machinery or standing on vibrating platforms. Some work environments where WBV is of concern include mining, farming, construction, trucking, sailors, helicopter pilots, and industrial equipment. 

 Health Concerns from WBV

  • Low-back pain and back disorders
  • Neck-shoulder disorders
  • Digestive and Circulatory disorders
  • Cochleo-vestibular and Reproductive effects


    Determining Whole-Body Vibration Risk

    Some questions that can be used determine if further action may be required:

    • Have workers reported back disorders?
    • Do employees operate vibrating machinery for long periods of time each day?
    • Are workers driving on rough road surfaces?
    • Are personnel exposed to shock or jolts?
    • Have machinery manufacturers warned of whole-body vibration risk?

    When further action is needed, there are two ways with which human vibration exposure can be determined. The first is to use tables of predetermined machine vibration levels combined with measured exposure times to estimate a total exposure.  The second method is to measure the exposure using an instrument designed for this purpose such as the Larson Davis Human Vibration Meter Model HVM200.

    Measuring WBV Exposure

    Daily vibration exposure is dependent upon the magnitude of the vibration to which the worker is exposed and the duration of the exposure. Whole-body vibration levels are measured using a specially designed sensor (SEN027) which is a triaxial accelerometer built into a flexible disk that can be stood or sat upon.

    This sensor is connected to a meter like the HVM200 which implements the required frequency weighting filters and produces the results of the measurement. There are a variety of weightings used to measure whole body vibration - a short guide offers insight into when each should be used.

    Whole-Body Vibration Exposure Limits

    The European Union has set exposure limits in directive 2002/44/EC and the ACGIH has set limit values that follow the ISO 2631-1 standard for WBV.  These "action" and "limit" values are shown below for reference.

     Standard         Limit Values (likely health risk)   Action Values (caution)   
    ISO 2631-1
    A(8) = 0.9 m/s2
    VDV = 17 m/s1.75
     A(8) = 0.5 m/s2
    VDV = 8.5 m/s1.75
     EU Directive
     A(8) = 1.15 m/s2
    VDV = 21 m/s1.75
     A(8) = 0.5 m/s2
    VDV = 9.1 m/s1.75


    What You Can Do to Protect Workers

    By implementing a program to routinely measure the exposure of at-risk employees, companies can substantially reduce their risk for expensive work induced injuries. With the help of the Larson Davis HVM200 Human Vibration Meter you can implement a program to assess, mitigate and monitor risk by following the best practices outlined by the American Conference of Governmental Industrial Hygienists (ACGIH) and documented in ISO 2631-1, Evaluation of Human Exposure to Whole-body Vibration. Alternatively the European Union has issued Directive 2002-22-EC to specify an employer's obligations with respect to determining, assessing, and mitigating risk.  Effective programs should include these elements:

    • Identify potential health or safety risk for whole-body vibration
    • Measure worker exposure and compare to the  "action" and "limit values" provided in the specifications
    • Identify and implement risk controls
    • Measure the new vibration exposure in order to evaluate effectiveness of controls

    Calculating Daily Exposure Metric

    Vibration exposure can be assessed using metrics that are calculated and displayed by the HVM200.

      The Daily Vibration Exposure A(8) is calculated from the frequency weighted r.m.s acceleration measurements awx, awy, and awz and the measured exposure period Texp. The highest value of A(8)x, A(8)y, or A(8)z is the Daily Vibration Exposure, A(8).

      The Vibration Dose Value (VDV) provides an alternative evaluation of vibration exposure that is often used to give a better indication of the risks associated with "shock" or "peak" events. The VDV is a cumulative value that increases with measurement time.  The highest value of VDVexp,x, VDVexp,y, or VDVexp,z is the Vibration Dose Value, VDV.

      In the News

      Standards, Regulations & Directives

       Standard Description
      ISO 8041:2005 Standard for instruments measuring human response to vibration
      ISO 2631-1:1997 General requirements for measuring whole-body vibration
      ISO 2631-2:2003 Vibration in buildings
      ISO 2631-4:2001 Vibration of passengers and crew in fixed guideway systems such as rail
      ISO 2631-5:2004 Evaluation of vibration containing multiple shocks
      ISO 6954:2000 Vibration on ships with regard to habitability
      ISO 7096:2000 Evaluation of earth moving machinery seat vibration
      ISO 10326-1:1992 Basic requirements for vehicle seat vibration
      ISO 10326-2:2001 Laboratory method for determine rail seat vibration

      For more information about whole-body vibration see the EU Good Practice Guide or  Safe Work Australia Guide.