HSE have launched a new webpage regarding the commissioning of Local Exhaust Ventilation (LEV) systems. LEV is a control measure that employers or other duty holders should use to reduce exposure to gases, vapours, dusts, fumes or mists that are produced by workplace activities/processes.
Extracting contaminants from the air, before people breathe them in, they are preferable to just providing a mask for people to wear, as LEV provides group protection to all site users and not just the individual mask wearer.
What the law says
Employers must assess and control the risks from exposure to substances due to the Control of Substances Hazardous to Health Regulations 2002 (as amended) (COSHH).
They must provide information and training to workers regarding the system and have it tested at least every 14 months, unless specified within a specific written scheme of examination.
LEV systems also present additional risks. Employers must control those risks to safety from fire, explosions and substances corrosive to metals under The Dangerous Substances and Explosive Atmospheres Regulations 2002 (DSEAR).
Employers must, where necessary, also consider compliance with The Control of Noise at Work Regulations 2005, to ensure that workers’ hearing is protected from excessive or cumulative noise in the workplace. Other regulations may also apply.
Commissioning proves that the LEV system is capable of providing adequate control.
Employers, should therefore commission LEV to make sure it adequately protects people from breathing in harmful substances, meeting their obligations under COSHH, which require that duty holders adequately control exposure to substances in the workplace that are hazardous to health, and in fact, cause ill-health. This:
- Ensures that there is adequate control from day one
- Proves that the system is providing adequate control
- Provides a benchmark for later regular examinations and tests
In the UK, occupational lung disease currently accounts for approx. 12,000 deaths a year which are likely linked to past exposure whilst at work.
The commissioning report
This should always include the:
- Date of the test;
- Duty holder’s name and address;
- Commissioner’s name, job title and employer.
The report should be signed appropriately by the commissioner, providing advice that is demonstrably impartial and competent.
Before using LEV
Ensure it has been checked, is suitable for the process and compatible with the substances being handled. The system should be installed correctly according to its design, its specification and any manufacturer’s instructions, or any specified technical performance markers.
For more information, see chapter 5 of HSG 258 – Controlling airborne contaminants at work: A guide to local exhaust ventilation (LEV) . This publication also provides guidance on:
- The roles and legal responsibilities of employers and suppliers;
- Competence;
- Principles of good design practice for effective LEV hoods and their classification;
- Ducts;
- Air movers;
- Air cleaners;
- System documentation.
Core elements of commissioning
The LEV commissioner should have:
- Identified the LEV system and location;
- Assessed control and demonstrated whether the LEV system adequately controls exposure to the hazardous substances by:
- Identifying the hazardous substances it is intended to control;
- Defining the process and how emissions occur;
- Defining the operating conditions;
- Detailing test methods and results;
- Defined benchmarks by providing performance targets such as flowrates and pressures, as reference for statutory examinations, maintenance and performance management
- Ensured the LEV system is correctly balanced and achieving the performance required at every hood in a system
LEV condition
The commissioning report should detail:
- The general condition of the LEV;
- The operating conditions at the time of commissioning, including any external factors that might influence performance;
- The general configuration, components, fan specification, filter media, waste collection, make-up air supply and discharge arrangements, location, photographs of relevant parts and assign identification number;
- Any minor adjustments or repairs carried out to make the LEV system effective;
- The methods used to judge performance, such as visual, smoke test, airflow measurements, pressure measurements, dust lamp, air sampling and filter testing.
Commissioning results
When provided with the results, information should be presented in such a way that it is easily understood. It should give enough information to update the user manual and logbooks after any defects have been resolved. It should include a simple summary describing the effectiveness of the system which includes:
- Quantitative assessment results such as volume flow rates, face velocities, duct velocities, static pressures, fan speed, motor speed with electrical power consumption and filter performance where applicable;
- Qualitative assessment results, including suitable observations;
- The results of any airflow indicators and relevant air sampling;
- A simple schematic with test points;
- A calibration certificate.
The commissioner should also provide information on the frequency of testing, if different from the statutory 14 months.
Training and information
Employees and operatives must be given suitable and sufficient information, instruction and training in the use of LEV.
Self-employed people have the same responsibilities as an employer and a worker to make sure other people are not exposed to hazardous substances.
To avoid causing harm, having accidents and facing prosecution,
ensure your business complies with health and safety law in 2025, by
- Conducting risk assessments as and when required (prior to undertaking activities).
- Providing training regarding the risks involved and how to manage them.
- Supervising risk management, as necessary, until competence is demonstrated.
- Formally reviewing risk assessments and associated safe systems of work, regularly.
- Updating training provided (toolbox talks, in-house or external formal training).
- Keeping / updating records of all the above processes.
Has this newsletter given you cause for concern? Need help with any health & safety related issues? Please do not hesitate to contact us.