Filtermist provides LEV testing in the UK for all types of extraction systems

For a free on-site survey of all your extraction systems contact our Service Department:

01952 290500
Filtermist service van

What is local exhaust ventilation testing (LEV testing)?

The continued widespread occurrence of occupational lung diseases in the UK has led to increasingly stringent guidelines and statutory requirements for Local Exhaust Ventilation (LEV).

In May 2008, Health and Safety Executive (HSE) published a new, comprehensive guide (HSG258) on LEV for designers, installers and examiners and detailed guidance for employers and their employees who depend on LEV to protect their health.


LEV systems must be tested every 14 months

The COSHH regulations require that all LEV systems are subject to a thorough examination. They also require most LEV systems to be tested every 14 months, including all oil mist, welding fume, smoke and dust extraction units that you currently have on site. This examination must be undertaken by a competent person and the tests and reports must conform to HSE standards. The HSG258 guideline on Controlling Airborne Contaminants provides the recommended procedures to achieve these statutory requirements.

Monitoring equipment and record keeping

Air flow monitoring equipment and record keeping systems as specified in HSG258 can be supplied as part of this service and are also available for purchase direct from Filtermist.

Expert analysis and practical recommendations

Filtermist provides comprehensive LEV testing for all makes and types of extraction equipment, working strictly in accordance with HSG258 guidelines. The Filtermist examination measures the air flow speed (velocity) of the air being extracted at the source and duct. The results are compared with the recommended velocities set by the HSE and our expert analysis, based on 40 years experience in the manufacture and design of LEV systems, allows us to provide practical advice and recommendations. The Filtermist report will have photos and/or schematic diagrams showing the Test Point, which will also be clearly identified on the ducting, as required by the HSE.

LEV Testing is required for compliance with health and safety standards and test reports often form part of a company's insurance requirement. Inadequate testing can result in employers being prosecuted, insurance being invalidated and employees getting ill.

Interpretation of the test results and subsequent recommendations concerning LEV equipment rely on the qualified expertise and practical experience of the LEV examiner.

Don't take the risk when commissioning your LEV tests

Filtermist have been trusted to take care of the LEV requirements of some of the worlds best known manufacturing operations since 1969. Our engineers provide a combination of in-depth application knowledge of LEV systems and are qualified in excess of the standard LEV testing requirements.

LEV reports

LEV test reports

Filtermist LEV Test Reports are comprised of 5 sections:

  • Introduction
  • The examination and testing procedure
  • Results and discussion
  • Conclusion
  • Recommendations

Supplementary to these sections is a one page system appraisal, workshop schematics, detailed measurement data and a full breakdown of the equipment used in the examination of the workplace.

This report can be used to form part of a company's insurance requirement and copies should be kept for a period of 10 years.


LEV Considerations

  • Should be carried out at least every 14 months.
  • Some applications require more frequent testing.
  • May form part of a company's insurance requirement.

HSE regulations

Further information on COSHH and Local Exhaust Ventilation can be found through the HSE website:


Recommended Further Reading


Free HSE leaflets:

Books: