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Routine Operation of LEV Systems

Ongoing checks to ensure system is fully operational

In addition to a statutory test, the Control of Substances Hazardous to Health (COSHH) Regulations 'Approved Code of Practice' (ACoP) requires that LEV systems be given a visual check at least once a week. This regular checking ensures that the system is working properly and identifies potential problems before the LEV performance deteriorates, so is important for ensuring its safe operation.

The requirements and frequency of visual checks will depend on the complexity of the system but often includes a daily check of:

  • the hood or inlet for a change of position or signs of damage
  • the condition of the ductwork for leaks and the dampers for function (where visible)
  • signs of damage (or partial disconnection) in areas of flexible ductwork
  • noise levels (increases may indicate turbulence, damage to mechanical bearings)
  • work area for signs of control failure (e.g. dust deposits, odours)
  • pressure gauges or airflow indicators
  • cleanliness of the filter or filter sock, filter bins not over filled
  • motorised filter shaking devices operational
  • correct water levels on wet scrubbers.
  • for fume cupboard specific checks: Good practice in the use of fume cupboards page for daily and weekly checks.
  • MSC's have additional user requirements, guidance can be found in the link under 'LEV user checks and Record Books'.

Departments are responsible for maintaining local records for the outcome of these visual checks, as well as information relating to repairs or remedial work carried out as a result of them. The records may be kept electronically, in a logbook, or in a weekly checklist. Further guidance and pro forma logbooks for recording these checks are available via the right-hand menu.

Where the system is found to be ineffective in extracting the hazardous material, it should be taken out of use until a remedy has been made, ensuring all who could be affected are informed and attach a notice to the affected equipment. An example of a notice can be found in the right column.

Maintenance of LEV Systems - in addition to the above, further information can be found here on routine maintenance.

Training - Process operatives have received appropriate training in the use and monitoring of LEV systems.

LEV User Checks and logbooks


Fume cupboards

Capture Hoods


Periodic check guidance:

Fume cupboards

Capture Hoods

Out Of Use sign