Devine Air environmental consultants logo

LEV Testing Explained: Legal Requirements for UK Businesses

vector image

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:

  • Welding and fabrication
  • Woodworking and dust extraction
  • Pharmaceutical manufacturing
  • Chemical processing
  • Laboratories
  • Spray booths

If your processes release substances hazardous to health, you are legally required to control exposure under the Control of Substances Hazardous to Health Regulations 2002 (COSHH).

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.

Related Posts

May 5, 2026
What Happens If LEV Testing Is Missed or Overdue

Local Exhaust Ventilation systems are installed to remove hazardous dust, fumes and vapours from the workplace before they reach workers. Like any mechanical system, they can lose performance over time if not properly checked and maintained. That is why regular testing is a legal requirement in the UK. If overdue LEV testing occurs, there is […]

Read More
April 28, 2026
Common LEV System Failures Found During Testing

Local Exhaust Ventilation (LEV) systems are designed to capture harmful dust, fumes and vapours before they enter the breathing zone. When these systems stop working properly, exposure risks increase quickly. Many problems develop gradually and are only discovered during a professional inspection. Understanding LEV system failures found during testing helps building owners and employers address […]

Read More
menu