LEV Testing Explained: Legal Requirements for UK Businesses
If your business generates dust, fumes, vapours, mist or gases, you have a legal duty to control exposure. Local Exhaust Ventilation (LEV) systems are often central to that control, but installing them is not enough. UK law requires regular thorough examination and testing to ensure they remain effective and compliant.
At DevineAir, we support UK businesses with LEV testing, design and consultancy to ensure systems meet current Health & Safety and COSHH requirements. In this guide, we explain what the law requires, how often testing must be carried out, and what enforcement authorities expect from you.
What Is LEV and When Do You Need It?
Local Exhaust Ventilation (LEV) systems are designed to capture airborne contaminants at source before they enter the workplace atmosphere. They are commonly used in:
Under COSHH, you must prevent exposure where reasonably practicable. Where that is not possible, you must adequately control it. LEV systems are often central to meeting this requirement.
The Legal Requirement for LEV Testing
Regulation 9 of COSHH requires employers to ensure that control measures are:
Maintained in efficient working order
Kept in good repair
Thoroughly examined and tested at suitable intervals
For most LEV systems, this means a Thorough Examination and Test (TExT) at least every 14 months, unless a shorter interval is specified in your risk assessment.
In Great Britain, enforcement is carried out by the Health and Safety Executive (HSE). HSE provides detailed technical guidance in HSG258, Controlling airborne contaminants.
Failure to meet the 14-month requirement can lead to enforcement action.
What Does a Thorough Examination and Test Involve?
LEV testing is more than a quick check to see if the system switches on. It’s a detailed assessment to make sure your ventilation is actually doing the job it was designed to do.
A proper, compliant examination will usually include:
Looking closely at hoods and capture points to see if they’re positioned and working correctly
Measuring airflow rates and velocities to confirm enough air is being extracted
Checking static pressure levels within the system
Inspecting ductwork for leaks, damage or blockages
Assessing the condition of filters
Testing fan performance
Comparing results against the original design specifications
Deciding whether the system is still fit for purpose in your current working environment
The aim is simple: to confirm that your LEV system is still effectively controlling exposure in line with your COSHH risk assessment.
If the system is no longer performing as it should, the issues must be addressed. Recording poor results without putting corrective action in place does not meet your legal duties. Compliance depends not just on testing, but on fixing what needs fixing.
Who Can Carry Out LEV Testing?
COSHH makes it clear that LEV testing must be carried out by a competent person. In simple terms, that means someone who genuinely understands how these systems work and how to assess whether they are protecting your workforce properly.
Competence usually includes:
Recognised qualifications, such as BOHS P601
Hands-on experience working with LEV systems
A solid understanding of airflow measurement and testing methods
Knowledge of how exposure to hazardous substances is controlled
It’s important to remember that the responsibility ultimately sits with you as the employer. Appointing a contractor does not transfer that duty. If the system is tested by someone who is not suitably qualified or experienced and enforcement action follows, saying you didn’t realise they lacked competence will not be a defence.
Record Keeping Requirements
You are legally required to keep records of LEV examinations and tests for at least five years.
Your records should include:
Identification of the LEV system
Date of examination
Measured technical data
Identified defects
Recommended actions
Confirmation of remedial works
These records demonstrate due diligence and must be available for inspection.
When Is More Frequent Testing Needed?
While 14 months is the general standard, some circumstances require shorter intervals.
Examples include:
High-risk carcinogenic dusts
Processes involving silica or pharmaceutical powders
Systems exposed to heavy wear or corrosive environments
Situations where your risk assessment identifies increased exposure risk
If your processes change or new substances are introduced, you must review your COSHH assessment and determine whether your LEV testing interval remains appropriate.
Common Compliance Failures
In practice, enforcement action often arises from:
Missing the 14-month deadline
Incomplete or unclear reports
Failure to act on identified defects
Modifying systems without revalidation
Inadequate documentation retention
Another frequent issue is assuming airflow readings alone confirm effectiveness. Adequate control depends on capture efficiency at source, not just overall air volume.
LEV compliance requires both technical accuracy and effective management oversight.
Consequences of Non-Compliance
The Health and Safety Executive regularly takes action against businesses where poor ventilation has put employees at risk. When LEV systems fail and people are exposed to harmful substances, enforcement is not uncommon.
The consequences can be serious and may include:
Improvement notices requiring you to fix issues within a set timeframe
Prohibition notices stopping certain activities altogether
Unlimited fines
Criminal liability for directors in serious cases
Greater exposure to civil compensation claims
But the impact goes beyond fines and formal notices. Ineffective LEV systems can contribute to occupational illnesses, higher sickness absence, lower productivity and long-term legal liability.
LEV compliance should not be treated as a box-ticking exercise. It is a fundamental part of protecting your people and managing business risk responsibly.
LEV Within a Broader Compliance Strategy
LEV testing is one component of workplace environmental compliance. Depending on your operations, you may also need:
An integrated approach ensures your control measures function effectively together and align with broader Health & Safety legislation.
DevineAir provides LEV testing, design, consultancy and maintenance across the UK and Ireland. Our consultants hold P601, P602, P603, P604, and W201 qualifications and provide tailored compliance services to businesses. In addition to LEV, we deliver air, noise, cleanroom, vibration, and light assessments, along with expert COSHH advice to help you meet your regulatory obligations.
Need Support With LEV Compliance?
If you are unsure whether your LEV systems meet current COSHH requirements, or if your 14-month testing deadline is approaching, now is the time to act.
DevineAir provides qualified LEV Thorough Examination and Testing, system design, maintenance support and expert COSHH advice across the UK and Ireland. Our certified consultants in P601, P602, P603, P604, and W201 deliver technically robust assessments and clear compliance reporting tailored to your business.
Contact DevineAir today to arrange your LEV testing or to discuss your wider environmental compliance requirements, including air quality, noise, cleanroom, vibration and light assessments.
Ensure your systems are compliant. Protect your workforce. Protect your business.
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