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Indoor Air Quality
Indoor Air Quality - Enhance Staff Productivity and Increase Wellness

Local Exhaust Ventilation (LEV) Testing

Local Exhaust Ventilation (LEV) is provided to protect workers who may be exposed to hazardous airborne dust, gases, vapours or fumes as part of their day-to-day work activities.

The control of Substances Hazardous to Health Regulations (COSHH) 2002 requires that exposure of employees to substances hazardous to health be either prevented or, where that is not reasonably practicable, adequately controlled.

The purpose of an LEV is to control the emission as close as possible to the point of release.  To be effective, an LEV must be well designed and constructed, properly used and maintained in good condition. Regulation 9 of COSHH states that:


  • LEV should be maintained in an efficient state, working order and in good repair
  • LEV should be examined and tested at least once every 14 months
  • LEV suitable record of the examination and test is kept for at least 5 years

The maintenance, examination and testing of LEV plant is to ensure that it operates as originally intended and to effectively capture and dispose of hazardous airborne substances.  LEV testing should comprise the following stages:

  • An initial appraisal of the LEV plant to determine whether it effectively captures and disposes of the emissions and whether it meets the designed specification and performance
  • Regular maintenance, including weekly visual checks and the routine replacement of components known to have a limited life including filters
  • Thorough examination and testing including observation and measurement of air velocities and flow rates with the results compared with the recommendations within the regulations