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LEV testing - brewing and distilling
Brewing and distilling generate several airborne hazards - the CO2 of fermentation, grain and malt dust, ethanol and process vapours. But they do not all need the same control, and getting that right matters: LEV suits some of them, while CO2 needs a different approach entirely.
The short answer
Brewing and distilling produce different airborne hazards that need different controls. Grain and malt dust, and process fumes and vapours, are point-source contaminants that local exhaust ventilation can capture at source - and where LEV controls a health hazard it must be tested. But CO2, the major hazard of fermentation, is different: it is an asphyxiant that displaces oxygen across a whole space, so it is controlled by dilution ventilation and gas monitoring, not by LEV. Matching the right control to each hazard is what actually keeps a brewery or distillery safe.
Several hazards, not one
Brewing and distilling are not single-hazard processes - they generate a mix of airborne hazards, and treating them as one thing, or assuming one control covers them all, misses what each needs. Fermentation produces carbon dioxide in quantity. Handling grain and malt produces dust. Distilling and the process generally produce vapours, including ethanol. Each of these is an airborne hazard, but they are different in nature, and crucially they call for different controls. So the first step in controlling a brewery or distillery's air is recognising it has several distinct hazards, not one.
This matters because the right control depends on the nature of the hazard, and these hazards differ fundamentally. Some are point-source contaminants that can be captured where they are generated; one - CO2 - is an asphyxiant that fills a space and displaces oxygen. Local exhaust ventilation suits the former but is not the right tool for the latter. So understanding the mix of hazards, and that they need different controls, is essential to controlling them properly - because applying the wrong control, such as expecting LEV to deal with CO2, would leave a serious hazard inadequately addressed.
Dust and fumes: LEV at source
For the dust and the process fumes, local exhaust ventilation is the appropriate control, because these are point-source contaminants - generated at specific points where they can be captured. Grain and malt dust is produced at handling, milling and transfer points, and LEV can capture it at those points before it disperses; combustible grain dust also carries an explosion risk if it accumulates, another reason to control it at source. Process vapours and fumes, produced at specific points in the process, can similarly be captured at source by extraction before they reach workers.
So where the hazard is a dust or a fume generated at a point, LEV is the control - capturing it where it is produced, as extraction does for airborne hazards generally. And where that LEV is controlling a health hazard, it falls under the same regime as any LEV: it must be thoroughly examined and tested to confirm it is genuinely capturing the contaminant. So for the dust and fume hazards of brewing and distilling, LEV is the right tool, applied and tested as it would be anywhere - capturing the point-source contaminant at source, and verified to be doing so.
CO2 is different
Carbon dioxide, the major hazard of fermentation, is a fundamentally different kind of problem, and it is important to be clear that LEV is not the right control for it. CO2 is an asphyxiant - it does not poison in the way a toxic vapour does at low levels, but it displaces oxygen, and in a confined or poorly-ventilated space it can build up to concentrations that are dangerous or fatal, well before it fills the space entirely. Fermentation produces a lot of CO2, and it collects in low or enclosed areas because it is denser than air, creating a hidden asphyxiation risk.
The reason LEV is not the answer for CO2 is that CO2 is not a point-source contaminant to be captured at a hood - it is a gas that fills a space and displaces the oxygen throughout it. So the control is not local capture but whole-space management: dilution ventilation to keep the CO2 from accumulating to dangerous levels, and gas monitoring or detection to warn when it does. In confined spaces - tanks, vessels, cellars - it means testing the atmosphere before entry and monitoring while inside. CO2 is controlled by ventilating the space and monitoring the air, not by extracting at a point, because its nature as a space-filling asphyxiant calls for a whole-space approach.
Matching the control to the hazard
So the key to controlling brewing and distilling hazards is matching the right control to each, rather than applying one approach across the board. For the point-source hazards - grain and malt dust, process fumes and vapours - LEV is the control, capturing them at source, and it must be tested where it controls a health hazard. For CO2, the whole-space asphyxiant, the control is dilution ventilation and gas monitoring, with confined-space precautions where relevant - not LEV. Each hazard gets the control its nature calls for.
Getting this matching right matters because the wrong control leaves a hazard inadequately addressed. Expecting LEV to handle CO2 would be a serious error, because local capture cannot control a gas that fills the whole space - CO2 needs ventilating and monitoring. Equally, relying only on general ventilation for the point-source dust and fumes would let those disperse when they could be captured at source. So a brewery or distillery needs the full picture: LEV, tested, for the dust and fumes it suits, and ventilation with monitoring for the CO2 it does not. Matching each control to each hazard is what genuinely keeps the operation safe.
The takeaway
Brewing and distilling produce a mix of airborne hazards that need different controls. Grain and malt dust and process fumes and vapours are point-source contaminants that local exhaust ventilation can capture at source - and where that LEV controls a health hazard, it must be tested like any other. But CO2, the major hazard of fermentation, is different: it is an asphyxiant that displaces oxygen across a whole space, so it is controlled by dilution ventilation and gas monitoring, with confined-space precautions, not by LEV.
So the essential point is matching the right control to each hazard rather than assuming one covers them all. LEV, tested, for the dust and fumes it suits; ventilation and monitoring for the space-filling CO2 it does not. Getting that right is what genuinely keeps a brewery or distillery safe - because expecting LEV to control CO2, or neglecting to capture the dust and fumes at source, would each leave a real hazard inadequately addressed. Different hazards, different controls, each matched to what its nature requires.
Questions
A mix - carbon dioxide from fermentation, grain and malt dust from handling, and process fumes and vapours including ethanol. They are different in nature and call for different controls, so treating them as one, or assuming one control covers all, misses what each needs.
The point-source ones - grain and malt dust, produced at handling and milling points, and process fumes and vapours produced at specific points. LEV captures these at source before they disperse, and where it controls a health hazard it must be thoroughly examined and tested.
Because CO2 is not a point-source contaminant to be captured at a hood - it is an asphyxiant gas that fills a space and displaces the oxygen throughout it. Local capture cannot control a space-filling gas, so CO2 needs a whole-space approach instead.
By dilution ventilation to keep it from accumulating to dangerous levels, and gas monitoring or detection to warn when it does - with confined-space precautions (testing the atmosphere before entry and monitoring while inside) for tanks, vessels and cellars where it collects.
Because it is an asphyxiant that displaces oxygen, and fermentation produces a lot of it. In a confined or poorly-ventilated space it can build up to dangerous or fatal concentrations, and it collects in low or enclosed areas because it is denser than air - a hidden asphyxiation risk.
Matching the right control to each - LEV, tested, for the point-source dust and fumes it suits, and ventilation with monitoring for the space-filling CO2 it does not. The wrong control leaves a hazard inadequately addressed, so each needs the control its nature calls for.
We test the LEV controlling grain dust and process fumes in breweries and distilleries - and can advise where CO2 needs ventilation and monitoring instead, so each hazard gets the right control.
