Home / LEV Testing / Guide
LEV testing - the label
After a thorough examination, many examiners leave a coloured label on the LEV system - green, amber or red - as an at-a-glance summary of its status. It is a useful, visible signal, but it is a summary, not the full story. Knowing what each colour means, and what the label does and does not tell you, helps you use it properly.
The short answer
A coloured LEV label is a common way examiners mark the outcome of a thorough examination at a glance. Broadly, green means the system was found to be controlling exposure adequately at the time of the test; amber means it is working but has defects that need attention; and red means it is not adequately controlling exposure and should not be relied upon. It is a helpful visible signal, especially for anyone on the floor, but it is a summary of the examiner's finding - the full detail, the measurements and the specific defects and actions are in the written examination report, which is what actually matters.
What the label is
A coloured label on an LEV system is a practical convention: after carrying out a thorough examination, many examiners fix a label to the system giving its status as a traffic-light colour, often with the test date and when the next is due. The idea is simple and useful - anyone looking at the machine can see at a glance whether the extraction on it has been examined and what the examiner concluded, without having to find and read the report. It puts the headline status where the work actually happens, on the equipment itself.
The colour scheme follows the familiar traffic-light logic: green for good, amber for caution, red for stop. Applied to LEV, it summarises whether the examiner found the system controlling exposure as it should. It is worth being clear that this labelling is a helpful industry practice rather than the formal substance of the examination - the substance is the written report and its findings. But as a visible, immediate signal of status, the coloured label does a real job, particularly for supervisors and operators who need to know quickly whether a machine's extraction can be trusted.
Green and amber
A green label means the system was found to be adequately controlling exposure at the time of the examination - it did what it is supposed to do, capturing the contaminant effectively, with no defects serious enough to undermine that. Green is the outcome you want: it says the extraction on this machine can be relied upon to protect the people using it, as verified by the examiner's measurements. It is still a moment-in-time finding - green at the test does not guarantee green forever - but it means the system passed.
An amber label is the middle ground: the system is working but has defects that need attention. It might be controlling exposure for now but showing signs of decline, or have faults that are not yet critical but will become so if left - a filter approaching the end of its life, a minor leak, wear that has begun to affect performance. Amber is a call to act before the defects tip the system into failure: the extraction is not condemned, but it needs the identified work doing to keep it reliable. Ignoring an amber finding is how a system drifts from working-but-flawed to no-longer-controlling, so amber should be treated as a genuine prompt, not a soft pass.
Red
A red label is the serious one: the system was found not to be adequately controlling exposure. Whatever the reason - the airflow too low, capture velocity below what the process needs, a significant fault - the examiner has concluded that this LEV is not doing its job, and so the people relying on it are not being properly protected. A red finding means the extraction cannot be trusted to control the hazard, and the situation needs addressing before the process should continue to rely on it.
This is where the label matters most, because a red-labelled system is one that looks like it is working - it runs, it hums, the fan turns - but has been found not to be. Without the label, an operator would have no way of knowing; with it, the status is visible on the machine. A red finding calls for prompt action: the defects that caused the failure have to be put right and the system's control restored and confirmed, and in the meantime the exposure has to be managed another way. Red is the colour that turns a hidden failure into a visible, actionable one - which is precisely the value of labelling the system at all.
The label is a summary, not the report
Useful as it is, the coloured label is a summary, and it should not be mistaken for the whole examination. The colour compresses the examiner's finding into one signal, but the substance - the measurements taken, the specific defects found, the actions recommended, and the evidence that the system does or does not control exposure - lives in the written examination report. An amber or red label tells you there is something to do; the report tells you what. So the label points you to the report; it does not replace it.
This matters for acting properly on a finding. A green label is reassuring, but the report still holds the measurements and any observations worth noting for next time. An amber label needs the report to know which defects to address. A red label needs the report to understand what failed and what has to be put right. Treating the colour as the complete answer - green means forget it, red means something vague is wrong - wastes the detail that makes the examination useful. The label is the flag; the report is the information. Use the colour to know the status at a glance, and the report to act on it properly.
The takeaway
A coloured LEV label is a common, practical way examiners mark a system's status at a glance after a thorough examination: green means it was controlling exposure adequately at the test, amber means it is working but has defects needing attention, and red means it is not adequately controlling exposure and should not be relied upon. It puts the headline status on the equipment, where operators and supervisors can see it immediately - which is genuinely useful, especially for catching a red-labelled system that still looks like it is running fine.
But the colour is a summary, not the substance. The measurements, the specific defects and the recommended actions are in the written examination report, which is what you act on. So use the label for what it is good at - an at-a-glance signal of whether a machine's extraction can be trusted - and go to the report for the detail behind it. Amber and red are prompts to read the report and act; green points to a report worth keeping. The flag and the information work together.
Questions
It is an at-a-glance summary of a thorough examination's outcome that many examiners leave on the system. Broadly: green means the system was controlling exposure adequately at the test, amber means it works but has defects to address, and red means it is not adequately controlling exposure.
That the system was found to be adequately controlling exposure at the time of the examination - capturing the contaminant effectively with no defects serious enough to undermine that. It is a moment-in-time finding, so green at the test does not guarantee green forever, but it means the system passed.
That the system is working but has defects needing attention - it may be controlling exposure now but showing signs of decline or carrying faults that will worsen if left. Amber is a prompt to do the identified work before the defects tip the system into failure, not a soft pass to ignore.
That the system was found not to be adequately controlling exposure - the airflow too low, capture velocity insufficient, or a significant fault. The extraction cannot be trusted to control the hazard, so the defects must be put right and control restored, and meanwhile the exposure managed another way.
No. The label is a summary that compresses the finding into one colour. The substance - the measurements, the specific defects, the recommended actions - lives in the written examination report. The label points you to the report and tells you the status; the report tells you what to do about it.
Because a failing LEV still looks like it is working - it runs and the fan turns - so without the label an operator would have no way of knowing it had been found not to control exposure. The red label makes a hidden failure visible on the machine, turning it into something that can be acted on.
Our thorough examination gives you a clear status for each system and a written report behind it - so the label on the machine is backed by the measurements, defects and actions that actually tell you what to do.
