Guide to LEV

Why is controlling peoples exposure to workplace airborne contaminates at work by the use of effective LEV systems so vital in protecting workers health in the UK? Below are just a few of the reasons why effective LEV matters.

Our LEV thorough examination and test involved a three stage process as outlined in HSE guidance HSG 258. The test procedure for each system includes where appropriate:

Stage 1Thorough visual and structural examination
Thorough external examination of all parts of the system for damage, wear and tear.
Internal duct and hatch examinations.
Checks that any filter cleaning devices (shake-down, reverse or pulsed jet work correctly.
Inspection of filter fabric. Where filters have built-in pressure gauges, checks on their function and pressure setting.
Checks of the water flow and sump condition in wet scrubber.
Checks that monitors and alerts/alarms (including returned air) are functioning
Inspection of the air mover drive mechanism (fan belts).
Checks for indications of effectiveness.

Stage 2 Measure technical performance
Measuring the air velocities at suitable test points indicated in the system documentation. This includes hood faces, branch ducts and the main duct.
Measuring static pressure at suitable test points indicated in the system documentation. This includes all hoods, ducting, across the air cleaner and fan.
Checking the fan speed, motor speed and electrical power consumption.
Checking make-up air.
Testing alarms.
Measuring air temperatures. Testing the air cleaning performance (recirculating system).

Volume flows rates are calculated and recorded and a comparison with the design specification or previous thorough examination is made; any discrepancies and diagnoses are contain in the report.

Stage 3 Assess control effectiveness
Assessment of how effective the LEV is at controlling operator's exposure..
A detailed assessment of the level of control, including reference to workplace monitoring results, observation of working methods and comparison with internal benchmarks is given in

Paragraph 349 of HSG 258 "Controlling airborne contaminates at work - A guide to local exhaust ventilation (LEV) sets out the information required in a system assessment report, this information includes

The name and address of the employer responsible for the LEV.
The date of examination and test.
The date of last thorough examination and test.
The identification and location of the LEV The process and hazardous substance concerned
The conditions at the time of the test and whether this was normal production or special conditions
A simple diagram of the LEV layout and location, with test points.
The condition of the LEV system including hood serial numbers and photographs of relevant parts.
Its intended operating performance for adequately controlling the hazardous substance and whether it is still achieving the same performance
The methods used to make a judgement of the performance and what needs to be done to achieve that performance, eg visual pressure measurements, airflow measurements, dust lamp, air sampling, tests of check the effectiveness of the filters.
The results of any air sampling relevant to LEV performance.
Comments on the way operators used the LEV.
Comments on system wear and tear and whether components may need repair or replacement before the next annual test.
The name, job title and employer of the person carrying out the examination and test.
The signature of the person carrying out the examination and test.
The details of any minor adjustments or repairs carried out to make the LEV system effective

All our LEV Through Examination Test Reports (TeXT) cover these basic requirements set out above and more.

Workplace airborne contaminates cause a range of occupational diseases.

UK 1500 people contract occupational asthma each year.

Exposure to fumes, chemicals and dusts are estimated to account for around 4000 deaths each year from Chronic Obstructive Pulmonary Disease (COPD).

Exposure to certain industrial processes increases the risk of occupational cancers.

It has been estimated that 10% of UK business operate processes that create a respiratory risk. (source " Disease Reduction Programme cross-cutting LEV Project - Local Exhaust Ventilation (LEV) demography in the UK" James and Wheeler and Andrew Darnton.

Only 40% of the 140,000 LEV systems in use in the UK are 'annually' tested as required by COSHH regulation 6. This of course means that 60% of all systems are not tested.

Of the 40% that are tested many are tested badly and poorly maintained.

500,000 people in the UK may rely on LEV systems to protect their health, many of these systems are not doing their job and people are being put at risk.

Enviro Safety Partnership is registered in England as a limited company; Registered No: 652792
Registered Address: Bank Chambers, Market Place, Melbourne, Derbyshire, DE73 8DS

Our aim is to make sure LEV systems are doing their job and protecting peoples health, we do this by testing systems and giving effective advice.