What is LEV testing?

LEV Testing is the process of thoroughly inspecting and evaluating a local exhaust ventilation system against the commissioning report’s performance, industry standards, and HSE guidelines. It includes airflow and pressure measurements, as well as checks on the effectiveness of contamination exposure control. All equipment, including hoods, filters and ducts, is also subject to additional inspections.

According to the HSE’s Occupational Lung Disease in Great Britain 2022 report, 12,000 lung disease deaths each year are estimated to be linked to past exposures at work. This has led to increasingly stringent guidelines and statutory requirements for Local Exhaust Ventilation.

HSE published the third edition of HSG258 ‘Controlling airborne contaminants at work: A guide to local exhaust ventilation (LEV)’ in 2017. This guide provides guidance on the design of new local exhaust ventilation (LEV) equipment. It describes the principles of deciding on, designing, commissioning and testing effective LEV.

How often do I need LEV testing?

LEV systems must be tested every 14 months.

Regular LEV testing by a competent person is a legal requirement of COSHH (Control of Substances Hazardous to Health) regulations.

This applies to 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. HSG258 provides the recommended procedures to achieve these statutory requirements.

Expert analysis and practical recommendations

Our P601, P602, and P604 qualified engineers perform COSHH compliant LEV testing for systems that control contaminants such as oil mist, dust and fume. We provide reports in digital format which make them simple to file and retrieve whenever needed.

The results are compared with the requirements specified in the original system design and our expert analysis, based on 50 years’ experience in the manufacture and design of LEV systems, allows us to provide practical advice and recommendations.

Filtermist LEV reports include photos and/or schematic diagrams showing the Test Points, which are also clearly identified on the ducting, as required by the HSE. Follow this link for more details on our comprehensive LEV Test Reports.

LEV Considerations

  • LEV Tests should be carried out at least once every 14 months.
  • Some applications require more frequent testing.
  • Tests must be undertaken by a competent person.
  • The test report may form part of a company's insurance requirement.

What equipment is required to perform an LEV test?

  • Manometer / pitot tube
  • Hotwire anemometer
  • Rotating vane anemometer
  • Rotation sensor (optional, useful piece of equipment)
  • Tyndall Beam Lamp
  • Smoke Generator suitable to fill an oil mist enclosure.
  • LEV Test Labels
  • Clearance time Labels
  • Capture distance Labels

Our LEV test procedure

Filtermist will LEV test, check and quantify a system's performance with these testing methods.

  • Review of RAMS
  • Review of previous LEV test / Commissioning Report / Service Schedule
  • Review of the working practice and process
  • Visual or Borescope Off line inspections of the Motor, Filters & body
  • Visual or Borescope inspections of external and internal ducting condition
  • Fan / motor rotation check
  • Face velocity tests
  • In duct velocity and pressure tests. (Rigid only, not flexible ducting in line with BOHS standards)
  • Negative pressure tests
  • F Monitor / pressure gauge recording
  • Oil drainage correct. (hoses connected, no droops in flex)
  • Smoke Clearance time test
  • Indicative particle count test
  • Capture distance calculation
  • Air change calculation ACH

Only the above tests specific to the system being tested will then quantify the system's performance and control the exposure of the harmful contaminate from the personnel to a level as low as reasonably practicable (ALARP).

LEV Reports

Filtermist LEV Test Reports are comprised of five sections:

  1. Introduction
  2. The examination and testing procedure
  3. Results and discussion
  4. Conclusion
  5. 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 Testing