When you have LEV installed, you must then have a report from the installer which summarises how the installation has met successfully with the design criteria set for the LEV. Both of these tasks are always carried out by competent engineers experienced in the design and validation of LEV, often a qualification issued by BOHS (British Occupational Hygiene Society). If you’re wondering what one might look like CIBSE have an example document on their website: Link
It’s helpful to draw an analogy here with other more common reports, such as a handover certificate when you have electrical or gas work completed by a competent engineer. Read our succinct and helpful summary on what a LEV commissioning report should contain below, and if you have questions and are (or want to be) a Safety~net Competent Person Scheme member, please contact us for further information and guidance.
An LEV (Local Exhaust Ventilation) commissioning report is a formal, documented record that proves a newly installed or significantly modified LEV system is operating exactly as it was designed to, and that it provides the necessary protection for employees from hazardous substances in the air.
In the UK, under the COSHH (Control of Substances Hazardous to Health) Regulations, employers have a legal duty to ensure that any control measure (like an LEV system) is maintained in an efficient state and in good working order. Commissioning is the critical “first step” in this process.
What is the Purpose of the Report?
The report serves as the “Baseline” for the system. Once a system is commissioned, all future routine examinations and tests (TExT) will be compared against these initial results to ensure the system hasn’t degraded over time.
It confirms three main criteria:
- Design Compliance: Does the system achieve the required airflow, velocity, and pressure identified in the original design specification?
- Safety Performance: Is it effectively capturing, conveying, and removing hazardous substances (fumes, dust, vapours) from the worker’s breathing zone?
- Instruction & Training: Does the system have clear documentation, and are the operators trained on how to use it correctly?
Key Components of an LEV Commissioning Report
A professional commissioning report should include:
- System Description: Details of the layout, ductwork, fan, and filtration units.
- Design Specifications: A summary of the design intent (e.g., the target capture velocity or required volume flow rate).
- Measurement Data:
- Flow Rates: Air volume measurements at the hood and throughout the ductwork.
- Pressure Readings: Static pressure measurements across the system.
- Face Velocities: The speed of air moving into the hood (crucial for capture).
- Visual Evidence: Photographs of the installation and any testing points (e.g., test ports in ducts).
- System Integrity: Checks for leaks in ductwork or blockages in the filtration unit.
- Verification of Performance: Results from smoke tests or tracer gas tests to visualize airflow and confirm it is actually capturing the contaminants.
- User Instructions: Confirmation that a logbook is in place and that users understand how to use the system (e.g., not blocking hoods).
Why is this Report Critical?
- Legal Compliance: Without a commissioning report, you technically do not have a record that the system was ever “fit for purpose” when it was installed.
- Insurance & Liability: In the event of a workplace health issue (such as respiratory problems related to dust or fumes), this report is your primary evidence that the company took adequate steps to control exposure.
- Maintenance Benchmark: You cannot effectively perform routine maintenance if you do not know the “correct” performance numbers established at commissioning.
A Note on Competence
The person conducting the commissioning must be competent. They should have the necessary skills, knowledge, and experience—often evidenced by relevant qualifications (such as those from the British Occupational Hygiene Society – BOHS) or through professional engineering bodies—to perform the measurements accurately and interpret the results correctly.
