LEV Compliance
Compliance · Compliance overview
LEV compliance is the practical process of ensuring that local exhaust ventilation systems meet the requirements of COSHH Regulation 9 and the guidance set out in HSE HSG258. For UK employers who use LEV to control hazardous substance exposure, compliance is not a one-off certification — it is an ongoing cycle of design review, thorough examination, testing, maintenance, record-keeping and corrective action that demonstrates the control remains effective while the process is in operation.
What LEV compliance means in practical workplace terms
LEV compliance means that every local exhaust ventilation system installed to control hazardous airborne substances is suitable for the process, properly maintained, thoroughly examined and tested at the required intervals, and supported by documentation that proves the system performs as intended. It is a legal obligation under Regulation 9 of the Control of Substances Hazardous to Health Regulations 2002 (COSHH), and it applies to the employer who operates the equipment — not solely to the installer or maintenance contractor.
In practice, compliance starts with a clear understanding of what each LEV system is supposed to capture, how the process has changed since installation, and whether the current hood geometry, airflow rates, filter condition and user practice still match the risk assessment that justified the control. It continues with scheduled examination, testing and repair; accurate records of findings; and a management system that ensures deficiencies are closed out in a reasonable timeframe.
How LEV supports COSHH risk management
COSHH requires employers to prevent or adequately control exposure to hazardous substances. Where exposure cannot be prevented by eliminating the substance or changing the process, the hierarchy of control directs employers toward engineering solutions before relying on procedural or personal protective measures. Local exhaust ventilation is the most common engineering control for airborne contaminants in UK workplaces.
LEV compliance supports COSHH risk management by providing evidence that the engineering control is actually working. A risk assessment that identifies LEV as the primary control measure must be supported by performance data: face velocities, capture zone assessments, transport velocity checks, filtration efficiency and discharge verification. Without this evidence, the risk assessment is incomplete and the employer cannot demonstrate that exposure is controlled as low as is reasonably practicable.
Regulation 9 is explicit. It requires that LEV systems be maintained in efficient working order, kept clean, and subject to thorough examination and testing at least every 14 months — or more frequently where the risk assessment or the nature of the process demands it. The examination must be carried out by a competent person, and the results must be recorded and kept available for inspection.
Why examination, testing, maintenance and records matter
These four activities form the operational core of LEV compliance, and each serves a distinct purpose. Examination is the visual and functional inspection of the system — hoods, ducts, fans, filters, controls and discharge — to identify wear, damage, blockage, leakage or deterioration that could impair performance. Testing is the measurement of quantitative performance indicators such as face velocity, duct velocity, static pressure and airflow volume, compared against the design intent or the minimum criteria in HSG258.
Maintenance is the routine servicing that keeps the system operating: filter replacement, fan belt tension checks, bearing lubrication, duct cleaning where settling occurs, and repair of damaged components. Records tie these activities together and provide the audit trail that demonstrates compliance over time. The log should include the date and scope of each examination, the test results, any defects found, the remedial actions taken, and the signature or accreditation of the competent person who carried out the work.
Records are also essential for identifying trends. A gradual decline in face velocity over successive test cycles may indicate fan wear, increasing system resistance from filter loading, or undocumented changes to the process that have increased the contaminant load beyond the original design.
The role of HSG258 and LEV TExT
HSE guidance document HSG258 — Controlling airborne contaminants at work: A guide to local exhaust ventilation (LEV) — is the authoritative reference for LEV design, examination, testing and management in Great Britain. It sets out the principles of capture, transport, filtration and discharge; describes the criteria for effective hood design; and explains what a thorough examination and test should cover. It is not statute, but it is the benchmark against which competent persons and enforcing authorities assess LEV systems.
LEV TExT — the thorough examination and test protocol described in HSG258 — is the structured inspection and measurement process that produces the compliance record. A competent person following HSG258 examines the hood position and condition, measures face velocity or capture performance, checks the ductwork and fan, reviews filter and discharge arrangements, and records the findings against a clear pass, fail or advisory classification. The report should state whether the system is adequate for the current process, identify any defects, and provide a target date for remedial action.
What employers commonly need to evidence
When an enforcing authority inspects or when a claim or incident triggers a review, the employer needs to produce a coherent package of evidence. This typically includes:
- The COSHH risk assessment that identified LEV as the required control measure, with the substance, exposure route and task clearly stated.
- The LEV system specification or commissioning report that shows what the system was designed to capture, at what airflow rate, and for which process configuration.
- A current inventory of all LEV systems, including location, process served, date of last examination, next due date, and responsible person.
- Thorough examination and test reports for at least the previous five years, or since installation if newer.
- Maintenance records showing routine servicing, filter changes, repairs and modifications.
- Evidence that defects identified in reports have been closed out, including any temporary control measures and follow-up test results.
- User training records that confirm operators understand how to position work, keep hoods clear, and report problems.
Common compliance gaps
Despite the clarity of the regulatory framework, the same compliance weaknesses appear repeatedly across UK workplaces. Recognising them early can prevent enforcement action and, more importantly, can prevent the exposure that enforcement is designed to stop.
- Poor capture — hoods moved, removed or resized to suit a new process or workpiece, with no reassessment of whether the design still works.
- Missing or incomplete records — test reports lost, not kept for the required period, or lacking detail about what was examined and what was found.
- Damaged ductwork — leaks, corrosion, dents or disconnected joints that reduce transport velocity and allow contaminants to escape into the building.
- Weak maintenance programmes — filters replaced only when airflow is visibly poor, fans run to failure, and bearing wear ignored until the motor burns out.
- Unsuitable user practice — operators bypassing the system because it is perceived as inconvenient, positioning work outside the capture zone, or using compressed air to clean down instead of vacuum extraction.
- Failure to act on test defects — advisory or fail items noted in examination reports but not remediated within a reasonable timeframe, sometimes because there is no clear process for assigning responsibility.
How LEV findings should be prioritised into practical actions
Not every defect demands immediate shutdown. A competent prioritisation approach distinguishes between critical failures that require the process to stop until the LEV is restored, significant impairments that need scheduled repair within days or weeks, and advisory items that should be addressed at the next maintenance window or during planned upgrades. This triage is typically documented in the examination report and should be reviewed by the person responsible for health and safety alongside the production or facilities manager.
The action plan should assign ownership, set deadlines, and define how the effectiveness of the repair will be verified — usually by a follow-up test or focused measurement. Where a temporary control is needed, such as a mobile extractor or respiratory protective equipment, the interim measure should be time-limited and reviewed regularly until the permanent fix is completed and tested.
Frequently asked questions
How often must LEV be thoroughly examined and tested?
At least every 14 months under COSHH Regulation 9. Some systems may need more frequent testing where the risk assessment indicates higher exposure potential, the process is particularly hazardous, or previous examinations have shown rapid degradation.
Who can carry out a LEV thorough examination and test?
A competent person — someone with the necessary knowledge, skills, experience and independence to carry out the examination thoroughly and interpret the findings against HSG258. This may be an internal engineer with appropriate training or an external specialist provider.
What happens if LEV records are missing?
Missing records make it impossible to demonstrate compliance. The employer should arrange a fresh thorough examination and test, establish a record-keeping system, and ensure future examinations are scheduled and completed on time. Enforcement action may still be taken for the period when records were not available.
Related pages