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LEV testing - the ongoing duty
An LEV certificate from last year proves the system worked then. COSHH is not interested in then - it is a continuing duty to control exposure now. Here is why a past pass is reassurance, not compliance.
The short answer
A past LEV pass shows the system was controlling exposure at the time of the test. It does not show it still is. COSHH imposes a continuing duty to keep exposure adequately controlled and the LEV in efficient working order, with a thorough examination and test at least every 14 months - because systems degrade, processes change, and control that was adequate then can be inadequate now. Last year's certificate is not current compliance.
The nature of the duty
COSHH does not ask whether your extraction once worked - it requires that exposure is adequately controlled while people are being exposed, which is a continuing state, not a past event. The duty to keep the LEV in efficient working order runs every day the system is relied on, not just on the day it was tested. A certificate is a snapshot; the duty is a film.
That is why a pass has a shelf life. It is strong evidence about the moment it was taken and progressively weaker evidence about the present as time passes and the system is used. Treating it as permanent proof misreads what COSHH is actually asking, which is that the control is adequate now.
Why systems drift
The reason the duty is continuous is that LEV does not hold its performance. Filters load, ductwork slowly leaks or partially blocks, a fan loses efficiency, a hood gets nudged out of position, or a workstation is added that robs airflow from the others. None of these stops the system running, and none of them announces itself - so a system that passed comfortably can drift below adequate control within months, invisibly.
A certificate cannot see the future. It records the system as it was, but the very things that degrade it happen after the test, in normal use. That gap between a past pass and present performance is exactly what a fresh examination exists to close - and why the law sets a maximum interval rather than trusting a one-off result.
The 14-month limit
COSHH sets the outer limit at 14 months - a thorough examination and test at least that often, sooner where risk or wear demands it. The point of the interval is precisely that a pass does not last indefinitely: the law assumes the system will drift and requires it re-checked before too long has gone by. A test more than 14 months old does not just look stale; it means the statutory duty to test has been missed.
So last year's pass can fail on the calendar alone. If the interval has lapsed, there is no current thorough examination and test on record, which is a breach regardless of how well the system was performing at its last check. The certificate has an expiry built into the duty.
What changes reset
Time is not the only thing that erodes a pass. A significant change to the process or the system - a new or moved workstation, a changed substance, an altered layout, a modification to the extraction - can undermine the control the certificate confirmed, sometimes well before the interval is up. Adding a capture point can rob airflow from the others, so an apparent improvement can quietly reduce control elsewhere.
In those cases the honest position is that the old pass no longer describes the system that now exists. The certificate was valid for the system as tested; change the system and it needs re-checking, because COSHH cares about the control that is actually in place, not the one that used to be.
The practical position
The constructive response is to treat LEV testing as a rolling duty rather than an annual box. Keep the thorough examination and test current - within the interval, and sooner after any significant change - maintain the system between tests so it does not drift, and keep the records that show the duty has been met continuously. That is what turns a series of passes into genuine compliance.
Seen that way, last year's certificate is not compliance but part of a history that has to be kept going. It did its job for its moment; the duty now is to make sure there is a current pass describing the system as it is today, backed by the upkeep that keeps the control adequate in between.
Questions
No. A past pass shows the system worked then, not that it works now. COSHH is a continuing duty to control exposure and keep the LEV in efficient working order, with testing at least every 14 months.
Because LEV degrades in normal use - filters load, ductwork leaks or blocks, fans lose efficiency, hoods move - so a system that passed can drift below adequate control within months, invisibly. A certificate cannot see the future.
At most 14 months, the statutory maximum interval, and sooner where risk or wear demands it. A test older than that means the duty to test has been missed, regardless of past performance.
Yes. A significant change - a new or moved workstation, a changed substance, an altered layout, a modification to the extraction - can undermine the control the certificate confirmed, sometimes well before the interval is up.
Keep the thorough examination and test current, test sooner after any significant change, maintain the system between tests, and keep the records that show the duty has been met continuously.
Yes. If the interval has lapsed there is no current test on record, which is a breach of the duty to test regardless of how the system is performing.
We keep your LEV testing current on the COSHH cycle and help you maintain it in between, so compliance is continuous.
