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Effectiveness of technical safety fume cupboards

Technical ventilation systems capture dusts and vapours at the source of danger before they are dispersed through the air in the room and enter the breathing zone. However, they differ in their effectiveness due to different types of construction. In the following, we explain the legal basis for the collection of pollutants at the workplace, the so-called STOP principle and the advantages and disadvantages of different extraction systems.

Compliance with occupational exposure limits

In almost all areas of industry and the public sector, employees carry out activities with hazardous substances. Without effective pollutant detection, airborne hazardous substances such as dusts and vapours can spread in the room, enter the breathing zone and sometimes cause considerable damage to health.

The employer is obliged to recognise the hazards at the workplace and to take appropriate protective measures. For activities involving hazardous substances, occupational exposure limits indicate the concentration of a substance up to which no acute or chronic harmful health hazard is generally expected.

If complete containment cannot be realised, at least the occupational exposure limits must be complied with.

Priority of protective measures according to the STOP principle

The STOP principle indicates the order of priority of protective measures. The individual letters stand for different types of protective measures:

S - Substitution
T - Technical protective measures
O - Organisational protective measures
P - Personal protective measures

The prioritisation of protective measures is given from left to right in descending order of priority. If sources of danger cannot be excluded ("S"), technical protective measures ("T") are used. These include, among others, extraction systems and fume cupboards.

Effectiveness of extraction systems

Extraction systems differ in their effectiveness due to different types of construction. Often, however, sufficient effectiveness is only achieved through a combination of different measures. For example, an installed technical protective measure only remains effective in the long term if it is regularly checked and maintained as an accompanying organisational protective measure within the framework of a maintenance plan.

At source capture

With localised extraction at the point of origin, e.g. by means of an extraction arm or at source extraction, the occurrence of hazardous substances in the air at the work area is reduced, but cannot be excluded. Further measures still need to be taken to comply with the OE

Fume cupboard with glass front

A fume cupboard is an effective extraction system. Compliance with the occupational exposure limits must at least be assumed. The effectiveness must be checked, e.g. by measurements. The front panel ensures retention of emissions, but also restricts the working area.

HazMat Workplace with ejector technology

The VARIO-Flow HazMat Workplace with ejector technology is also an effective extraction system. Here, however, the emissions are captured by the supply air ("push principle") and transported into the extraction system ("pull principle"). The front work area remains completely open.

VARIO-Flow Hazardous Material Workplaces

VARIO-Flow hazardous material workplaces from DENIOS are suitable for activities involving chemicals that can release airborne pollutants such as vapours or dusts. The optimally coordinated interaction of supply and exhaust air ("push-pull principle") ensures efficient and safe containment. The prescribed workplace limit values are complied with and employees are effectively protected from absorbing substances that are hazardous to health.

How it works

The entire front area of the VARIO-Flow Workplace is open. The supply air is drawn in from the workspace via the front opening and via a radial fan. The supply air is forced into the aluminium tubular frame, which is equipped with ejector nozzles at the top and bottom of the front area that are inclined inwards by 45°. The excess pressure escapes via the ejector nozzles in the form of targeted fresh air curtains. The fresh air curtains drive the hazardous vapours towards the rear baffle wall, where they are specifically extracted via the exhaust air ("push-pull" principle). The standard built-in monitoring unit ensures functional reliability. For targeted exhaust of the exhaust air, VARIO-Flow HazMat workplaces must be connected to a suitable exhaust air system.

How it is biult

The VARIO-Flow Workplace is available in 27 sizes (24 nEx, 3 Ex versions) with different dimensions. It can be positioned on an existing floor space or assembled in a modular way. For this purpose, various work surfaces, media connections, a base frame and base cabinets are available. In the base cabinets, the required hazardous materials can be safely stored directly at the workplace. Customised versions, for example with weighing stone or washbasin, are available in consultation.

3-times tested safety

VARIO-Flow hazardous material workplaces from DENIOS Ireland are highly effective in ensuring that no vapours, gases or suspended particles pollute the air that employees breathe. This is confirmed by recognised test procedures.


Testing according to EN 14175-3

VARIO-Flow hazardous substance workplaces are type-tested according to EN 14175-3 and thus comply with the requirements of the laboratory guidelines and the hazardous substances ordinance.


Gravimetric dust measurement

The measurement of the gravimetric dust concentration proves: VARIO-Flow hazardous material workplaces from DENIOS ensure excellent retention capacity in applications with dusts.


Potassium iodide test

The KI-Diskus test confirmed the required level of protection according to EN 12469 for the VARIO-Flow hazardous material workplaces.


Do you have a very special application and are not sure whether it can be carried out in the VARIO-Flow hazardous material workplace? We will be happy to advise you!

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The specialist information on this page has been compiled carefully and to the best of our knowledge and belief. Nevertheless, DENIOS AG cannot assume any warranty or liability of any kind, whether in contract, tort or otherwise, for the topicality, completeness and correctness either towards the reader or towards third parties. The use of the information and content for your own or third party purposes is therefore at your own risk. In any case, please observe the locally and currently applicable legislation.

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