21 May Everything you should know about Local Exhaust Ventilation (LEV)
Local exhaust ventilation (LEV) systems play a critical role in protecting workers from exposure to hazardous airborne contaminants in a wide range of industries. Whether managing dust, fumes, vapours, mists or smoke, a correctly designed, installed and maintained LEV system helps to control risks at the source, and therefore reducing the likelihood of occupational illnesses and ensuring regulatory compliance.
At EMADA, we are committed to promoting the use of properly designed and installed LEV. This guide provides an overview of what you need to know about LEV, employer and employee responsibilities, and how to maintain effective systems.
What is Local Exhaust Ventilation (LEV)?
LEV is an engineering control system designed to capture and remove airborne contaminants before they can be inhaled by workers.
A typical LEV system includes:
- Capture hood(s) to collect contaminants at the source
- Ductwork to transport the captured air
- Air cleaner or filter to remove harmful substances
- Fan to move the air through the system
- Discharge outlet to release cleaned air safely into the atmosphere or return it to the workplace if appropriate
By removing contaminants before they disperse into the working environment, LEV systems offer an effective method for controlling exposure risks.
Why is LEV Important?
Exposure to hazardous airborne substances can lead to serious health conditions, including occupation asthma, lung diseases and cancer.
According to the Health and Safety Executive (HSE), approximately 12,000 deaths each year are estimated to be linked to past exposures at work.
Installing, using and maintaining effective LEV systems not only protects employee health but also supports legal compliance under the Control of Substances Hazardous to Health (COSHH) regulations 2002.
Responsibilities Under COSHH
Employer Responsibilities
- If LEV is used as a control measure under COSHH, employers must ensure:
- Systems are correctly designed for their intended purpose.
- Employees are trained to use LEV properly.
- Maintenance is carried out according to manufacturers’ instructions.
- Thorough Examination and Testing (TExT) is undertaken at least once every 14 months, or more frequently if required.
- Accurate records of maintenance and testing are kept.
Further guidance can be found in HSE publication HSG258: Controlling Airborne Contaminants at Work – A Guide to Local Exhaust Ventilation (LEV).
Employee Responsibilities
Employees must:
- Use LEV systems properly whenever they are provided
- Report any damage or faults with LEV systems immediately
- Carry out basic pre-use checks when required
Maintaining good communication between workers and management is essential for identifying and addressing any issues quickly
LEV Testing and Maintenance
Frequency of LEV Testing
All LEV systems must undergo a Thorough Examination and Test (TExT) at least once every 14 months by a competent professional. However, some high-risk applications will require more regular testing.
Testing intervals depend on the type of contaminant, the process, and the risks involved. Regular testing helps to ensure systems remain effective over time.
More details can be found in HSG258.
Routine Inspection and Preventative Maintenance
Beyond statutory testing, daily, weekly and monthly checks should be carried out to monitor system performance. Simple visual inspections, airflow checks and filter maintenance help identify issues before they become serious problems.
Competency: Selecting the Right People
The HSE defines competency as a combination of training, skills, experience and knowledge necessary to perform a task safely and effectively.
When commissioning, maintaining or testing LEV systems, ensure the individuals or companies you work with are competent.
Choosing competent suppliers and service providers is crucial to ensure that LEV systems are not just installed, but also designed, operated and maintained correctly for your specific application.
Choosing the Right LEV System
A well-designed LEV system must be tailored to the specific process, the type of contaminant, the working environment, and the operational needs of the business. Considerations include:
Type of contaminant (dust, mist, fume, vapour etc)
Amount of contaminant generated
Work patterns and exposure durations
Positioning and effectiveness of capture hoods
Maintenance access and ease of inspection
The HSE publication Clearing the Air: A Simple Guide to Buying and Using Local Exhaust Ventilation (LEV) offers practical advice on specifying and purchasing LEV systems.
Common Pitfalls to Avoid
Poor system design: Ineffective hood placement or incorrect airflow rates can make systems ineffective.
Lack of user training: Even the best system is useless if it is not used correctly.
Neglected maintenance: Filters, fans and ductwork require regular attention to maintain efficiency.
Inadequate record-keeping: Failing to document inspections and tests can leave businesses exposed to enforcement action.
Stay Informed
The field of workplace health and safety, including LEV standards and best practice, is always evolving. To stay updated on the latest developments, guidance and practical advice for employers, employees and LEV system providers, we invite you to subscribe to the EMADA newsletter.
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