LEV Servicing: What Gets Done Between Thorough Examinations

Most employers know they need a thorough examination and test on their LEV system every 14 months. Fewer realise that COSHH Regulation 9 also places a separate, ongoing duty on them between those tests — to keep the system in working order at all times.

There is a practical difference between a thorough examination and test and ongoing servicing. The TExT is a formal inspection by a competent person that verifies performance. Servicing is what you do in between to ensure performance is maintained. Both are legal duties. Neither replaces the other.

The Legal Basis for Ongoing Servicing

COSHH Regulation 9(1) requires every LEV system provided as a control measure to be "maintained in an efficient state, in efficient working order, in good repair and in a clean condition."

This duty is continuous, not periodic. It does not reset after a TExT. A system that passes its 14-month test can still fall into breach of Regulation 9 within weeks if it is not serviced and maintained properly. The legislation makes no distinction between small dust extractors and large centralised extraction systems — both are subject to the same maintenance standard.

There are three elements to the duty:

Efficient state — the system captures and removes the hazardous substance it was designed to control. Performance must be adequate for the task, not merely functional.

Efficient working order — all components operate correctly. Fans run at the right speed, dampers move freely, filters are not overloaded, seals are intact.

Good repair — nothing is broken, worn, or deteriorating. A cracked duct, a damaged bag, a corroded fan housing — these need fixing, not watching.

The regulation means that waiting for a problem to become visible is not a compliant approach. Maintenance under COSHH is proactive.

What Servicing Actually Involves

LEV servicing sits between two other maintenance activities that sometimes get confused with it: user checks (the daily and weekly observations your own staff carry out) and the formal TExT inspection (the 14-month competent-person examination).

Servicing is planned, recurring mechanical work — the kind that gets scheduled in advance rather than triggered by a breakdown. For most LEV systems it covers:

Filter and Media Replacement

Filters capture the dust, fume, or vapour your LEV is extracting. As they fill, resistance to airflow increases, extraction performance drops, and the system works harder to achieve the same capture. A clogged filter does not just reduce efficiency — it can cause the fan motor to overheat and fail.

The replacement schedule depends on the type of filter and the process it is serving:

Dust extraction bag filters used in woodworking or general dust extraction typically need inspection and replacement on a schedule set by the manufacturer and adjusted for actual usage. A busy workshop may need bag changes every few weeks; a lighter-use system may go longer.
Cartridge filters and HEPA filters used for fine or hazardous dusts (including some silica and pharmaceutical dust extraction applications) have rated service lives that must not be exceeded. The filter manufacturer's datasheet is the reference.
Carbon or chemical filters used in solvent and vapour extraction have saturation lives. Running a carbon filter past saturation means vapour passes straight through.

Keep records of filter change dates. This is part of the maintenance record you are required to keep under Regulation 9(4).

Fan and Motor Checks

The fan generates the airflow that carries contaminants away from the worker's breathing zone. Key checks that belong in a servicing visit:

Fan belt tension and condition — on belt-driven fans, a loose or worn belt means reduced fan speed and reduced airflow. Belt checks and replacements are routine servicing tasks.
Fan blade inspection — blades can accumulate dust deposits that unbalance the impeller and increase wear on bearings. On systems extracting sticky or fibrous material, blade cleaning is part of regular servicing.
Bearing lubrication — according to manufacturer schedules; dry bearings fail silently before they fail audibly.
Motor current draw — an elevated current reading compared to the nameplate value can indicate the fan is working harder than it should (usually a sign of increased filter resistance or reduced duct cross-section from accumulation).

Ductwork Inspection

Ductwork deteriorates in ways that are not visible from outside. On a servicing visit, check for:

Dust accumulation in horizontal runs. Settled dust in ductwork reduces the effective bore, increases velocity, and eventually blocks the duct.
Leaks and gaps at joints, flanges, and connections. A leak anywhere between the hood and the fan reduces the negative pressure available at the capture point. Even small leaks add up.
Corrosion on external surfaces, particularly around joints in damp environments. Internal corrosion from aggressive fumes (acid mists, solvent vapours) can degrade duct life faster than external wear.
Flexible hose condition — flexible connections crack and deform with age and heat cycling. Replace before they fail rather than after.

Hood and Intake Checks

The hood or capture point is where LEV actually does its work. It also gets the most physical abuse — knocked, moved, blocked, and modified. A servicing check should confirm:

The hood is in the correct position and has not been moved since the last test.
There are no obstructions to airflow at the intake.
Flanges and faces are intact and have not been modified.
Slot faces are clear and not partially blocked by settled dust.

Cleaning

Accumulated dust inside ductwork and collection equipment is a fire and explosion risk for some dusts (wood dust, flour, and fine metal dusts can be explosive under certain conditions), and a health risk if it re-enters the air during disturbance. Cleaning frequency depends on the type of dust being extracted. HSE considers cleaning to be part of the maintenance duty under Regulation 9(1).

How Often Should LEV Be Serviced?

There is no single statutory service interval in COSHH (beyond the 14-month TExT cycle). The correct answer depends on the system type, the process it serves, the manufacturer's recommendations, and experience from previous servicing visits.

A practical framework:

Follow the manufacturer's service schedule as a baseline. It covers the components they designed and the failure modes they know.
Adjust for actual usage and environment. A dust extractor running eight hours a day in a heavily loaded environment needs more frequent attention than one running two hours a week. A system extracting corrosive vapours will degrade faster than one handling inert dust.
Use the TExT findings. A thorough examination report that shows reduced airflow, increased filter pressure drop, or belt wear is a signal that the service interval should be shortened, not maintained.
Record every servicing visit with the date, work done, parts replaced, and who did it. COSHH Regulation 9(4) requires records of examinations, testing, and repair to be kept for at least five years.

Many employers opt for a formal annual servicing visit by a specialist contractor — timed to fall between TExT dates so the system receives two specialist visits per year rather than one. This is not a legal requirement, but it is good practice for systems that are heavily used. A servicing contractor is not the same as the competent person who carries out your TExT examination — servicing and formal examination are separate activities with different purposes.

Can Your Staff Service the System?

User checks — the daily and weekly observations described in our guide on user checks vs thorough examinations — can be carried out by trained employees with no specialist qualification. Basic maintenance tasks such as emptying collection drums and cleaning the work area around extraction points also sit within normal employee duties.

Planned mechanical servicing is different. Filter replacements, belt changes, bearing lubrication, and ductwork cleaning require the right tools, the right replacement parts, and an understanding of the system's design parameters. Some tasks — particularly on systems extracting hazardous dusts or fumes — require proper respiratory protection during the work itself. Whether you use an in-house maintenance team or a specialist contractor, the person doing the servicing needs to know what they are doing.

Connecting Servicing to Your Compliance Records

COSHH requires records of maintenance as well as examination and testing. A maintenance logbook — or digital equivalent — that captures every servicing visit, filter change, repair, and cleaning event gives you evidence that you are meeting the Regulation 9(1) duty continuously, not just at test time.

When the HSE visits, or when a testing contractor carries out your next TExT, those records demonstrate that the system has been looked after. A TExT report that shows deteriorated performance will be read in the context of your maintenance records. A gap in servicing records alongside reduced airflow figures points to the cause.

Our LEV record-keeping requirements checker works through what you need to keep and for how long. The LEV testing due date calculator tracks when your next TExT is due. Between those two deadlines, the maintenance schedule is your responsibility to set and follow.

Key Points

COSHH Regulation 9(1) requires LEV to be maintained in an efficient state and efficient working order at all times — not just after a TExT.
Planned servicing covers filter replacement, fan and motor checks, ductwork inspection, hood checks, and cleaning.
Service intervals are not set by statute — they are determined by the manufacturer's recommendations, the system's usage, and TExT findings.
Records of all maintenance, repair, and servicing must be kept for at least five years under Regulation 9(4).
Servicing is distinct from user checks (which your staff carry out daily/weekly) and from the formal 14-month TExT (which requires a competent person).

This guide is for information only and does not constitute legal advice. For guidance on your specific LEV systems and obligations, consult a competent person or the HSE's LEV guidance.