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LEV testing - dental and medical labs
A dental or medical laboratory looks like precise, clean work - and it is, but it generates two airborne hazards in the process: fine dust from grinding and polishing, and vapour from the acrylics and materials used. Both are real, and the extraction at the bench, tested to prove it works, is what keeps the technicians safe.
The short answer
Dental and medical laboratory work generates two airborne hazards: fine dust from grinding, polishing and finishing materials (acrylics, metals, ceramics and investment materials, some containing silica), and vapour from acrylics and chemicals used, such as methyl methacrylate. Both are harmful to breathe. Local exhaust ventilation controls them by capturing at the bench where the work is done, before technicians breathe them - and because it controls a health hazard, the LEV must be tested to confirm it genuinely captures. Bench extraction protects the technicians; testing proves it does.
Precise work, real hazards
Dental and medical laboratory work is precise, skilled, clean-looking work - making dentures, crowns, prosthetics and other precision items. But behind the precision, the processes generate two distinct airborne hazards that the clean appearance can obscure. Grinding, polishing, trimming and finishing the materials produces fine dust; and the acrylics and chemicals used in the work give off vapour. Both go into the air the technician breathes, and both are genuine health hazards, not incidental to the clean, careful nature of the work.
So a dental or medical lab is a workplace with real airborne hazards, despite not looking like a dusty or fumey environment. The dust from grinding and the vapour from acrylics are exactly the kind of airborne contaminants that require control, and the technicians working at the bench are exposed to them directly. The precise, clean impression of the work should not obscure that these two hazards - dust and vapour - are present and need controlling. Recognising both is the starting point for protecting the technicians who do this work.
The dust
The first hazard is dust. Grinding, polishing, trimming and finishing the materials used in dental and medical lab work - acrylics, metals and alloys, ceramics, and the investment materials used in casting - produces fine dust that becomes airborne. This dust is fine enough to be breathed deep into the lungs, and depending on the material it can be harmful in various ways. Investment and some materials can contain silica, and dust from grinding metals and alloys carries its own hazards depending on the composition - so the dust is not benign, and its harm depends on what is being worked.
Because the dust is generated at the bench, at the point of grinding and finishing, that is where it is released into the technician's breathing zone. A technician grinding and polishing throughout the day is exposed to a continuous production of fine dust right at their working position. So the dust hazard is real and directly at the point of work - fine, breathable dust from the materials being finished, generated exactly where the technician is working. Controlling it means capturing it at that bench, at the source, which is where local exhaust ventilation comes in for the dust side of the hazard.
The vapour
The second hazard is vapour, from the acrylics and chemicals used in the work. Dental and medical lab work uses materials such as acrylic resins - methyl methacrylate being a common one - and various chemicals, and these give off vapours that are harmful to breathe. Methyl methacrylate vapour, for instance, is an irritant with a workplace exposure limit, released as the acrylic is worked. So alongside the dust, the technician is exposed to vapours from the materials - a second, distinct airborne hazard from the same work.
The vapour is released where the acrylics and chemicals are handled and worked, at the bench, so like the dust it is generated right at the technician's working position. A technician working with acrylics throughout the day breathes the vapours released, repeatedly. So the lab has this second hazard - harmful vapour from acrylics and chemicals - in addition to the dust, both present at the bench where the work is done. Controlling the technician's exposure means addressing both the dust and the vapour, capturing both at the source, which is the bench where they are generated together.
LEV at the bench, tested
The control for both the dust and the vapour is local exhaust ventilation at the bench, capturing the contaminants at source before the technician breathes them. Bench extraction - a hood or downdraught bench at the working position - draws away the dust from grinding and the vapour from acrylics at the point they are generated, keeping both out of the technician's breathing zone. Capturing at the bench is the right control because that is where both hazards are released, and where they can be caught before dispersing into the air the technician breathes.
And as with any LEV controlling a health hazard, the bench extraction only protects the technician if it is genuinely capturing the dust and vapour - which testing confirms. The extraction degrades, and can quietly fall below the level needed to control the hazards, with no obvious sign. A thorough examination and test measures and observes whether the bench LEV is genuinely capturing both the dust and the vapour as it should, catching any shortfall before it becomes exposure. So the bench extraction is the technicians' primary protection, and the test is what proves it is working - keeping the technicians safe from both the dust and the vapour their precise work generates.
The takeaway
Dental and medical laboratory work generates two airborne hazards behind its precise, clean appearance: fine dust from grinding, polishing and finishing materials (acrylics, metals, ceramics and investment, some silica-containing), and vapour from acrylics and chemicals such as methyl methacrylate. Both are harmful to breathe, both are generated at the bench, and the technicians working there are exposed to both directly and repeatedly.
Local exhaust ventilation controls both by capturing at the bench, at the source, before the technician breathes them - the primary protection for lab technicians. And LEV testing keeps that protection real, confirming the bench extraction is genuinely capturing both the dust and the vapour, catching any silent shortfall before it becomes exposure. For technicians exposed to dust and vapour throughout their precise work, capturing both at the bench and testing the control is exactly what keeps them safe - the extraction doing the work, and the test proving it does.
Questions
Two - fine dust from grinding, polishing and finishing materials (acrylics, metals, ceramics and investment materials, some containing silica), and vapour from acrylics and chemicals used, such as methyl methacrylate. Both are harmful to breathe and generated at the bench.
From grinding, polishing, trimming and finishing the materials used in the work - acrylics, metals and alloys, ceramics, and investment materials. It becomes airborne as fine dust that can be breathed into the lungs, with harm depending on the material, including silica in some.
Vapour from the acrylics and chemicals used - methyl methacrylate being a common one, an irritant with a workplace exposure limit, released as the acrylic is worked. It is a second, distinct airborne hazard from the same work, alongside the dust.
By capturing both at the bench, at the source - a hood or downdraught bench at the working position draws away the grinding dust and the acrylic vapour where they are generated, before they disperse into the technician's breathing zone. Capturing at the bench addresses both together.
Because it only protects the technician if it is genuinely capturing the dust and vapour, and it degrades, often with no obvious sign. Testing confirms the bench extraction is genuinely capturing both hazards, catching any shortfall before it becomes exposure.
The precise, clean appearance can obscure the hazards, but the dust from grinding and the vapour from acrylics are real airborne contaminants, generated at the bench, that the technicians breathe directly. The clean impression does not make the hazards any less present.
We test the bench extraction in dental and medical labs - confirming it genuinely captures both the grinding dust and the acrylic vapour at source, so the technicians doing precise work are protected.
