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LEV Thorough Examination and Test: Proving Extraction Actually Works

LEV thorough examination and test (TExT) explained: what the 14-monthly statutory test covers, why airflow decays, and a worked capture-velocity example.

LEV thorough examination and test (TExT) is the statutory check, required under COSHH, that local exhaust ventilation systems still control the airborne contaminants they were installed to capture. Because most LEV must be examined and tested at least every 14 months, and because extraction performance decays invisibly, the TExT is often the only moment anyone actually measures whether the extraction works. This is an educational overview, not legal advice.

What the TExT covers

  • Technical performance: measured airflow and capture velocities at hoods against the system’s design or benchmark figures, not a visual "the fan runs" check.
  • Condition: ductwork, hoods, filters, fans, and dampers examined for damage, blockage, and wear.
  • Assessment of control: a judgment on whether the LEV still adequately controls exposure, with defects and required actions.
  • The report: a formal record retained (commonly at least five years) documenting the results.

The phrase that matters is thorough: this is a measured, competent examination, not the routine visual and airflow checks maintenance should already be doing between examinations.

Why LEV decays invisibly

Extraction fails quietly: filters load and restrict flow, ducts accumulate deposits, fan impellers wear, dampers drift, and someone adds a branch that steals airflow from an existing hood. None of it is visible to an operator standing at the hood, because captured contaminant and escaped contaminant look identical. The system can lose a large fraction of its capture velocity while appearing to run normally, which is precisely why a periodic measured test exists, and why fan maintenance and filter management between tests matter so much.

A worked example: the hood that dropped below capture

A woodworking shop’s extraction hood was commissioned with a capture velocity of 1.0 m/s at the working point, comfortably controlling dust. The TExT 14 months later measures 0.5 m/s at the same point: a loaded filter bank and a slipping fan belt have halved the airflow, and at 0.5 m/s a meaningful fraction of fine dust now escapes into the operator’s breathing zone rather than into the duct. The examiner records the LEV as not providing adequate control, requiring the filter change and belt correction before the system can be relied on. Between tests, this was invisible, and the exposure was real. A monthly filter-differential and airflow check would have caught it months earlier, which is why the smart plants treat the annual TExT as the backstop, not the primary defense.

Between the tests: the maintenance that keeps you passing

The 14-month test is a floor, not a program. Plants that only think about LEV at examination time drift out of control between tests; plants that run filter checks, airflow spot-checks, and fan care as routine work orders pass their examinations because the system never degraded far in the first place. The TExT then confirms performance rather than discovering failure. This is the same logic as any statutory examination, pressure systems, lifting equipment, the periodic legal check works best sitting on top of a real maintenance regime.

Where Fabrico fits

Fabrico does not perform TExT examinations, competent LEV examiners do that. What Fabrico provides is the schedule and evidence layer: every LEV system as an asset with its statutory examination date as a preventive schedule that escalates before it lapses, plus the between-test filter, airflow, and fan-care routines as recurring work orders with recorded readings; examination reports attached to the asset history; and defects escalated at health priority. The 14-month date never sneaks up, and the report library is ready when the inspector asks, under EU governance. EU-built, with EU data residency.

Frequently Asked Questions

How often must LEV be thoroughly examined and tested?

At least every 14 months for most systems, with shorter intervals for certain higher-risk processes specified in guidance. The 14-month interval (rather than 12) exists so the examination date rotates through the year and does not always fall in the same season or shutdown, but the duty is to examine before the deadline.

Does the TExT replace routine LEV maintenance?

No. The thorough examination is a periodic statutory check; it does not substitute for the routine cleaning, filter management, and airflow checks that keep the system in control between examinations. Relying only on the 14-month test means discovering failures long after they started.

What happens if an LEV system fails its examination?

The examiner records it as not providing adequate control and specifies the remedial action. Continued reliance on a failed system to control exposure is a COSHH failing, so the defects should be corrected and the control verified before the system is credited again.

Want the 14-month LEV examination tracked and the between-test upkeep evidenced? Book a Fabrico demo to see extraction compliance run through a field-ready CMMS.

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