Local Exhaust Ventilation Frequently asked Questions

What is Local Exhaust Ventilation Examination and Testing?

The COSHH regulations require that employers must carry out a risk assessment and decide on the measures necessary to protect their employees. In brief, one of the ways of providing protection for employees is to use a Local Exhaust Ventilation system. However, employers must ensure that their Local Exhaust Ventilation systems continue to operate efficiently. Consequently, it is necessary to have LEV Examination & Testing carried out. In particular, Local Exhaust Ventilation Testing and Examination should be at 14-month intervals or less for most systems. The records of the test must be kept for at least 5 Years and preferably for the life of the system

What is the purpose of Local Exhaust Ventilation examination and testing

A Local Exhaust Ventilation test is a detailed examination of the operation of an LEV system to ensure that it continues to operate as originally intended. In particular, it continues to control the exposure of your employees. Employers have a duty in law to ensure that the equipment is always working correctly and the LEV examination and test fulfills part of this requirement.

Who can undertake Local Exhaust Ventilation Examination and Testing

To ensure a correct LEV test, use a that tester possesses the specialist knowledge and experience and is competent. Follow this link to see Synergy’s LEV Testing service.

Why is competency important

Employers have a legal responsibility to ensure that they control and minimise their employees’ exposures to hazardous substances. For this reason, employing a competent person and following their advice will prevent your LEV system from not working properly.

How do I know if someone is competent?

A good way of telling if your LEV Tester is competent is that they will have a relevant qualification such as P601 – Thorough Examination & Testing of Local Exhaust Ventilation (LEV) Systems.

What Information does the examiner need?

Ideally, the examiner needs to know the original intended performance of the LEV system. The supplier of the system should supply a commissioning report verifying that it is working correctly. If this is not available then the examiner will have to carry out an initial appraisal and thorough examination to prove the system is suitable for its intended purpose.

What should be in a Local Exhaust Ventilation Testing Report

The report must show whether the system is still working as it was originally intended. Testers use several methods to assess this:

Visual checks

A smoke test can help to visualize the airflow into the system.
A dust lamp shows if the LEV hood captures or allows dust to escape.
Observations about the way the operator interacts with the system can provide useful information.
Inspection of the air cleaning device to check its condition.


Measurements of face velocity and capture velocity.
Measures of static pressures in the ducts.
Velocity measurements in the duct.
Measurements of pressure drop across the air cleaning device.

The report should detail the results of all of these tests, and based upon the results, should make an assessment of whether the system is working effectively or not. If the report shows that the system is not working effectively then it should make prioritized recommendations of the actions necessary to make it work properly again.

What should I do with the report?

To summarize, the report should clearly state if the LEV system has passed or failed to provide satisfactory protection. In addition, for systems that fail, the report must state the actions necessary for it to work correctly again.

To find out more about how we can help you with your LEV Systems and the other services we provide contact us now.


Call us on: 01782 614236 or email us at: info@synergy-environmental.co.uk


Further Reading

Follow this link to see the HSE’s Frequently Asked Questions.