Local Exhaust Ventilation Testing & LEV System Inspections

Local Exhaust Ventilation Testing & LEV System InspectionsLocal exhaust ventilation (LEV) systems play a critical role in protecting workers from airborne contaminants and hazardous substances. Across industries such as manufacturing, welding, engineering, woodworking, pharmaceuticals and construction, LEV systems capture dust, fumes, vapours and other contaminants at or near their source before they spread into the wider working environment.
Regular LEV testing helps ensure these systems continue to provide effective control. Under the Control of Substances Hazardous to Health (COSHH) Regulations, employers must keep control measures such as LEV in efficient working order and arrange appropriate examination and testing.
Businesses can also use digital compliance tools alongside processes such as risk assessment software to improve visibility across inspections, corrective actions, compliance records and reporting.
This guide explains how local exhaust ventilation systems work, how often LEV testing is required, what happens during an inspection and what employers need to consider when managing LEV compliance.What Is Local Exhaust Ventilation (LEV)?Local exhaust ventilation (LEV) is a control system designed to capture airborne contaminants at or near their source before workers can inhale them. By extracting contaminated air before it spreads through the workplace, LEV helps businesses control exposure to substances hazardous to health.
LEV systems are commonly used where workplace processes generate: Welding fumes Dust Oil mist Smoke Vapours Chemical emissions Fine airborne contaminantsA typical LEV system includes extraction hoods, ducting, filters and fans that work together to capture and remove contaminated air. Effective systems are designed to capture hazardous substances as close to the source as reasonably practicable, helping reduce worker exposure.
LEV equipment is commonly used in: Engineering workshops Manufacturing facilities Automotive repair centres Pharmaceutical environments Laboratories Construction sites Food production facilities Schools and colleges with workshops Woodworking businesses Industrial processing sitesWithout effective control measures, workers may be exposed to hazardous airborne substances that can contribute to occupational diseases including asthma, silicosis, chronic obstructive pulmonary disease (COPD) and some occupational cancers.Why LEV Testing Is ImportantLEV testing helps ensure an extraction system continues to operate effectively and control exposure to hazardous substances in the workplace. Over time, filters can become blocked, ductwork can deteriorate and other components may become damaged or less effective.
Regular LEV testing helps businesses: Protect workers from airborne contaminants Maintain compliance with COSHH requirements Identify faults and deterioration Confirm that control measures remain effective Maintain LEV equipment in efficient working order Reduce the risk of unexpected system failures Support wider workplace health and safety measuresRegular testing is particularly important in workplaces where dust, fumes, vapours and other hazardous substances are generated as part of everyday operations. An LEV system that is damaged, poorly maintained or no longer performing as intended may fail to adequately control exposure.
LEV can also provide more targeted control than general ventilation because contaminants are captured close to their source rather than being allowed to disperse into the wider workplace.COSHH Regulations & HSE RequirementsUnder the Control of Substances Hazardous to Health (COSHH) Regulations, employers must ensure that measures used to control exposure to hazardous substances, including LEV systems, are maintained in efficient working order, good repair and a clean condition.
Where LEV is used to control exposure, COSHH requires employers to arrange a thorough examination and test at least once every 14 months. Some types of LEV equipment may require more frequent examination and testing depending on the process and substances involved.
Employers should ensure LEV systems: Remain in efficient working order Are kept in good repair Continue to provide effective control Are regularly maintained and inspected Undergo the required thorough examination and testingRecords of thorough examinations and tests should be kept for at least five years. These records can help demonstrate that appropriate checks have been completed and provide a history of the system’s condition and performance.
Using tools such as COSHH assessment software can also help businesses manage hazardous substances, assessments, compliance records and corrective actions across different sites.
Failure to adequately control exposure to hazardous substances can result in enforcement action as well as increased risks to workers and disruption to business operations.
For organisations operating LEV equipment, compliance should therefore be treated as an ongoing process involving appropriate use, maintenance, inspection and testing rather than a one-off exercise.What Happens During an LEV Inspection?An LEV inspection involves a thorough examination and test of the system to determine whether it is functioning as intended and continuing to adequately control exposure to hazardous substances.
A competent person carrying out the examination will typically assess components including: Extraction hoods Ducting Fans Filters Airflow indicators Discharge points System controls Overall system conditionThe examination should consider whether the LEV system is still capable of controlling the contaminants and processes it was designed to manage.
Depending on the system, testing may include: Visual examination of the system Airflow measurements Pressure measurements Smoke testing or visualisation Face velocity measurements Contaminant capture checks Filter assessments Checks of warning devices and airflow indicatorsThe competent person should also look for deterioration such as damaged ductwork, leaks, blocked filters, worn components and changes to the workplace process that could affect LEV performance.
Following the examination, the business should receive a report documenting the condition and performance of the system. This should provide sufficient information to identify any problems and the remedial action required.
Where appropriate, previous test results and commissioning information can be used to compare current performance with the system’s intended operating conditions.
If testing identifies inadequate control, the business should take appropriate action to address the problem. This could involve maintenance, repairs, adjustments or further investigation before the system can once again provide effective control.How Often Should LEV Systems Be Tested?Most LEV systems used to control exposure to hazardous substances must undergo a thorough examination and test at least once every 14 months.
However, 14 months is not a universal interval for every type of LEV equipment. Certain processes and types of equipment require more frequent testing.
The appropriate examination frequency can depend on factors including: The type of LEV equipment The substances being controlled How frequently the system is used Workplace conditions The processes being carried out The potential consequences of system deterioration Relevant COSHH requirementsBusinesses should also distinguish between the statutory thorough examination and test and routine checks or maintenance. Waiting until the next formal examination is not sufficient if there are signs that an LEV system is no longer performing correctly.
Employees using LEV equipment should be encouraged to identify obvious problems such as unusual noise, visible dust or fumes escaping, damaged hoods or changes in airflow.
Routine maintenance, checks and the required thorough examination and testing work together to help ensure the system continues to provide adequate control.Who Can Carry Out LEV Testing?LEV thorough examinations and testing should be carried out by someone competent to assess the system and determine whether it continues to provide adequate control.
Competence depends on having the appropriate combination of knowledge, training, skills and practical experience for the LEV system being examined.
An LEV examiner may need knowledge of areas including: LEV system design and operation Airflow and pressure measurements Contaminant capture Hazardous substances Workplace processes COSHH requirements Workplace exposure limits Testing methods and equipmentRelevant professional training and qualifications, including those offered by the British Occupational Hygiene Society (BOHS), can help demonstrate technical knowledge. However, businesses should consider overall competence and experience rather than relying solely on a particular qualification.
When appointing someone to carry out LEV testing, employers should therefore establish that they have appropriate experience with the type of system, contaminants and workplace processes involved.Common LEV System IssuesLEV systems can deteriorate over time, particularly in demanding industrial environments. Changes to equipment or workplace processes can also affect how effectively an existing system controls contaminants.
Common problems identified during LEV inspections include: Blocked or damaged filters Damaged ductwork Leaks within the system Fan problems Reduced airflow Damaged extraction hoods Incorrectly positioned hoods Poor contaminant capture Worn components Inadequate maintenance Changes to workplace processes Problems with airflow indicatorsSome problems may be immediately noticeable, while others may only become apparent through examination and performance testing.
For example, an extraction fan may still operate even though reduced airflow means contaminants are no longer being adequately captured. Similarly, changes to machinery, processes or hood positioning can affect the effectiveness of an LEV system without causing an obvious mechanical failure.
Routine checks and maintenance can help identify deterioration between formal examinations and reduce the risk of workers being exposed to hazardous airborne substances.Benefits of Effective LEV SystemsAn effective LEV system captures contaminants before they spread into the wider workplace, helping reduce worker exposure to substances hazardous to health.
Effective LEV can help businesses: Control exposure to hazardous substances Protect workers from dust, fumes and vapours Maintain safer workplace conditions Support compliance with COSHH requirements Reduce the spread of contaminants Maintain cleaner working environments Identify and control exposure close to its sourceThe main advantage of local exhaust ventilation is its ability to deal with contaminants where they are generated.
Rather than relying solely on general ventilation to dilute contaminated workplace air, LEV captures and removes contaminants before they enter a worker’s breathing zone or spread throughout the workplace.
This makes properly designed and maintained LEV particularly important for processes that generate: Dust Welding fumes Oil mist Smoke Vapours Chemical emissions Fine particulate matterLEV should form part of a wider approach to controlling exposure to hazardous substances. Employers should assess workplace risks and use appropriate control measures based on the substances and processes involved.Managing LEV Inspections DigitallyBusinesses operating multiple LEV systems may need to manage examination dates, reports, maintenance records, remedial actions and supporting compliance documentation across different sites.
Relying on separate spreadsheets, paper records and emails can make it difficult to maintain consistent oversight of these activities.
Digital inspection and compliance processes can help organisations centralise information relating to: LEV inspection schedules Thorough examination and test reports Routine checks Maintenance records Identified defects Corrective actions Supporting documentation Inspection historyDigital inspection software can help businesses create more structured inspection processes and maintain accessible records across teams and locations.
This can be particularly useful when an LEV examination identifies remedial work. Instead of the issue remaining within an isolated report, businesses can record the required action, assign responsibility and maintain evidence of what has been completed.
Centralising inspection information can also make it easier to retrieve records when preparing for internal reviews, external audits or future LEV examinations.
Digital systems do not replace the need for competent LEV examination, testing and maintenance. They can, however, support the administrative processes surrounding compliance and provide greater visibility over outstanding actions and records.Why LEV Compliance MattersLEV compliance forms part of an employer’s wider responsibility to adequately control exposure to substances hazardous to health.
Where LEV has been selected as a control measure, simply installing the equipment is not enough. The system needs to remain effective throughout its working life.
Poorly performing LEV may allow workers to be exposed to contaminants such as: Hazardous dust Welding fumes Chemical vapours Oil mist Smoke Other airborne substances hazardous to healthRegular checks, appropriate maintenance and thorough examination and testing help employers identify deterioration and determine whether systems continue to provide adequate control.
Accurate records are also important. Examination reports, maintenance information and evidence of corrective actions provide businesses with a clearer history of each system and can help demonstrate how workplace exposure risks are being managed.
For organisations with multiple sites or numerous pieces of LEV equipment, having structured processes for managing these responsibilities can make ongoing compliance easier to oversee.LEV Testing Checklist for EmployersEmployers responsible for LEV systems should ensure that appropriate processes are in place throughout the life of the equipment.
Key considerations include: Identify which workplace processes generate hazardous airborne substances Ensure LEV is appropriate for the contaminant and process Provide workers with appropriate information and training Encourage users to carry out basic checks and report problems Maintain LEV equipment in efficient working order Arrange servicing and maintenance when required Arrange thorough examination and testing at the required intervals Use a competent person for LEV examinations Review examination reports and identified defects Complete necessary remedial actions Keep thorough examination and test records for at least five years Review LEV arrangements when workplace processes or equipment changeA structured approach helps businesses move beyond simply booking an LEV test every 14 months and instead manage the effectiveness of the system throughout the year.Final ThoughtsLocal exhaust ventilation plays an important role in controlling worker exposure to dust, fumes, vapours and other hazardous airborne substances.
Installing an LEV system is only one part of effective exposure control. Employers must also ensure systems are used correctly, maintained in efficient working order and thoroughly examined and tested at the appropriate intervals.
For most LEV systems, a thorough examination and test is required at least once every 14 months, although some types of equipment require more frequent testing.
Combining competent LEV testing with routine checks, maintenance and structured record keeping can help businesses identify problems earlier and maintain effective workplace control measures.
For organisations managing multiple systems or locations, digital inspection and compliance processes can also provide greater visibility over inspection schedules, reports, corrective actions and supporting records.FAQsWhat is local exhaust ventilation?Local exhaust ventilation (LEV) is an engineering control system that captures airborne contaminants such as dust, fumes, vapours and mist at or near their source before they spread into the wider workplace.Is LEV testing a legal requirement?Where LEV is used as a control measure under COSHH, employers must ensure it is maintained in efficient working order and undergoes the required thorough examination and testing. For most LEV systems, this is required at least once every 14 months.How often should LEV systems be tested?Most LEV systems require a thorough examination and test at least once every 14 months. Some types of equipment and processes require more frequent examinations, so businesses should establish the appropriate interval for their particular system.Who can carry out LEV testing?LEV testing should be carried out by a competent person with the appropriate knowledge, training, skills and experience to examine the system and assess whether it continues to provide adequate control.What happens if an LEV system fails its examination?If an examination identifies faults or inadequate control, the employer should review the findings and take appropriate remedial action. Depending on the issue, this may involve repairs, maintenance, adjustments or further investigation.What records should employers keep?Employers should keep records of thorough LEV examinations and tests for at least five years. Maintaining related maintenance records, corrective actions and system information can also provide a useful history of the equipment.What industries use LEV systems?LEV systems are commonly used in manufacturing, engineering, welding, woodworking, construction, automotive workshops, laboratories, pharmaceuticals and other workplaces where processes generate hazardous airborne substances.