DA · EN
Short explanations of the terms you meet when you choose a dust collector: capture velocity, filter classes, ATEX zones and hoses, and the laws and standards behind them. Each entry points to the tool or page where you can use it.
Jump to the topic you need.
Topic1Capture and airflow4 entries↓ Topic2Filters2 entries↓ Topic3ATEX and combustible dust4 entries↓ Topic4Hoses1 entry↓ Topic5Legislation7 entries↓ Topic6Standards11 entries↓ Topic7Guidance2 entries↓ Topic8Terms6 entries↓The air speed needed where the dust is released to pull it into the opening. The capture zone is the area in front of the opening where the air is fast enough. Recommended values run from 0.38 to 10.2 m/s, depending on how the dust is released.
Source: ACGIH, Industrial Ventilation, 30th edition, table 6-2
Dust in the air needs a large airflow at the capture point. Dust on surfaces needs a high vacuum. A vacuum cleaner built for surfaces does not remove dust that hangs in the air.
Source: NORRES hose data
Manufacturers state the airflow at full inlet, so we always show it with the inlet diameter. A smaller inlet or a smaller hose gives less air, with every manufacturer.
Source: Manufacturer data
An extraction arm can be bent into position over the work, with a flow regulator for the suction. At the same airflow, a larger hood gives slower air in front of it, so a larger hood needs more air.
Source: Depureco catalogue, page 4; airflow calculator
System classes under EN 60335-2-69 for the whole vacuum cleaner’s ability to retain hazardous particles, not the filter alone. Class H is required for carcinogens, fungal spores and asbestos.
Source: EN 60335-2-69, as on our Ex-Vac wiki
Filter classes under EN 1822-1 for the filter element: H13 with at least 99.95 % and H14 with at least 99.995 % efficiency at the most penetrating particle size. A HEPA filter does not by itself make a machine class H.
Source: EN 1822-1, as on our Ex-Vac wiki
Areas where an explosive dust atmosphere can occur are classified as zone 20, 21 or 22; for gas, zone 0, 1 or 2. The employer classifies the zones, and the machine’s marking must cover the zone it works in.
Source: Directive 1999/92/EC, as on our Ex-Vac wiki
Combustible dust is divided into IIIA (combustible flyings), IIIB (non-conductive dust) and IIIC (conductive dust, such as metal powders). Equipment marked IIIC can be used for all three groups; equipment marked IIIB is not for conductive dust.
Source: EN 60079-0, as on our Ex-Vac wiki
The European product standard for industrial vacuum cleaners and dust collectors for explosive atmospheres. It was harmonised under the ATEX Directive 2014/34/EU in March 2023.
Source: EN 17348:2022, as on our Ex-Vac wiki
The lowest surface temperature that can ignite a dust cloud or a dust layer, measured in °C. It decides which temperature class the machine needs, as shown in its ATEX marking.
Source: As on our Ex-Vac wiki
CP hoses for extraction arms and dust collectors with a fan. AIRDUC hoses for industrial vacuum cleaners. Find your machine’s maximum vacuum on its product page or rating plate. If it is not stated, ask us.
Source: NORRES factsheets
Regulates the design, manufacture and marking of equipment and protective systems for use in explosive atmospheres. All ATEX-certified equipment must carry the CE mark and be classified in category 1D, 2D or 3D (dust) or 1G, 2G or 3G (gas). The directive sets requirements both for product design and for the conformity assessment procedure: categories 1 and 2 require involvement of a notified body, whereas category 3 may be self-declared by the manufacturer. The directive is the legal basis for product standards such as EN 17348 and EN ISO 80079-36.
Source: as on our Ex-Vac wiki
Requires the employer to classify hazardous areas into zones (Zone 20, 21 and 22 for dust; Zone 0, 1 and 2 for gas), to prepare an explosion protection document and to ensure that the equipment placed in classified areas matches the zone category. Implemented in Denmark in July 2003 by the Working Environment Authority order BEK no. 478. Where the equipment directive 2014/34/EU regulates what is sold, the workers directive regulates how it is used.
Source: as on our Ex-Vac wiki
The Machinery Directive sets essential health and safety requirements for machinery, including industrial vacuum cleaners. CE marking is mandatory. The new Machinery Regulation 2023/1230/EU enters into force on 20 January 2027 and replaces the directive. Key changes are stronger digitalisation (digital technical documentation; AI-driven machinery gets its own regulatory regime) and a tightened list of high-risk machines. For ATEX vacuum cleaners, a machine still has to comply with both the Machinery Regulation and the ATEX Directive at the same time.
Source: as on our Ex-Vac wiki
The Danish Working Environment Authority's implementation of the ATEX Workers Directive 1999/92/EC. Requires the employer to classify hazardous zones, prepare a separate ATEX risk assessment and provide explosion protection documentation containing the zone drawing, risk assessment and documentation for the equipment used. Supplemented by AT Guidance C.0.9 (August 2005), which explains how the requirements are met in practice. The Working Environment Authority oversees the working-environment aspect, while the Danish Emergency Management Agency oversees the actual zone classification.
Source: as on our Ex-Vac wiki
Order from the Danish Emergency Management Agency on the identification, classification and marking of explosive atmospheres (zones). Defines requirements for the physical marking of Zone 20, 21 and 22 and for the associated zone drawing. The Danish Emergency Management Agency is the supervising authority. The order applies the principles of EN 60079-10-2 but is the legally binding reference in Denmark.
Source: as on our Ex-Vac wiki
CLP (Classification, Labelling and Packaging) regulates the classification and labelling of chemical substances in the EU based on the global GHS system. For ATEX and ACD work, CLP is relevant because the GHS02 hazard pictogram (flammable) together with hazard statements such as H228 (flammable solid) and H252 (self-heating in large quantities) is the formal basis for deciding whether a dust must be handled as combustible or explosive. The safety data sheet (SDS) is the practical contact point between the CLP classification and the choice of collection equipment.
Source: as on our Ex-Vac wiki
Protects workers against the risks of exposure to carcinogens, mutagens and reprotoxic substances at work. CMRD is the direct legal basis for the tightened European limit values for lead in blood (BLV) and lead in air (BOELV) that took effect in 2024 and triggered the new 0.03 mg/m³ limit. The directive requires that cleaning equipment and waste handling do not spread the contamination.
Source: as on our Ex-Vac wiki
European product standard that defines the requirements for design, construction, testing and marking of industrial vacuum cleaners and dust collectors for use in potentially explosive atmospheres. A central contribution is the concept of internal ATEX zone, classifying the explosion hazard inside the collection system itself. The standard explicitly covers accessories: hoses, couplings, nozzles and filters are an integral part of the requirements and cannot be left unregulated. It also introduces the designation WT (Wet Type Dust Collector) for liquid-bath solutions. Harmonised under the ATEX Directive 2014/34/EU in March 2023 and under the Machinery Directive in August 2024. Before EN 17348 there was no specific product standard for these vacuum cleaners, and the standard is the first unambiguous basis for professional comparison.
Source: as on our Ex-Vac wiki
The European standard for high-efficiency air filters. Defines classes E10–E12 (EPA), H13–H14 (HEPA) and U15–U17 (ULPA) based on the filter element's minimum efficiency at MPPS (Most Penetrating Particle Size). H14 = 99.995 % efficiency at MPPS and is typically used as the final stage in ATEX vacuum cleaners when handling hazardous or carcinogenic dust. For ULPA U15 and above, the standard requires mandatory scan testing (PAO/DOP method) to verify filter integrity.
Source: as on our Ex-Vac wiki
International standard that supplements EN 1822 with additional requirements for classification and testing of HEPA and ULPA filters. ISO 29463-5 covers efficiency measurement at MPPS. Used as an alternative or supplement to EN 1822, particularly for international projects or for export to markets outside the EU. The classification nomenclature in the two standards differs, but the calculation methods are built on the same principles.
Source: as on our Ex-Vac wiki
Defines the methodology for zone classification (Zone 20, 21 and 22) based on the likelihood and duration of an explosive dust atmosphere. Annex A gives indicative time intervals: Zone 20 > 1,000 hours/year, Zone 21 = 10–1,000 hours, Zone 22 < 10 hours. These figures are indicative and must not be read as absolute thresholds, but as an aid to risk assessment. Used together with the Danish Emergency Management Agency's order BEK 268/2010 in Denmark.
Source: as on our Ex-Vac wiki
Fundamental standard for the prevention of and protection against explosions in industrial plants. Describes the three conditions for an explosion (combustible material, oxygen and ignition source — the fire/explosion triangle) and the methods used to eliminate them. Clause 6.4 covers ventilation and the risk that incorrect ventilation may spread combustible dust into new areas. Supplemented by the ATEX directives and the EN 60079 series and is one of the core references in an explosion protection document.
Source: as on our Ex-Vac wiki
Defines construction requirements and test methods for non-electrical equipment (mechanical components, pumps, ventilation parts, accessories) in explosive atmospheres. The basis for the protection method Ex h: the construction is such that potential ignition sources cannot arise under normal operation. Electrical vacuum cleaners use Ex t (protection by enclosure) instead. Part -36 covers general requirements; part -37 covers specific protection types (Ex h c, Ex h b, Ex h k, etc.).
Source: as on our Ex-Vac wiki
Guidance standard for managing electrostatic hazards in explosive atmospheres. Sets principal requirements and indicative limit values for grounding resistance — including the guideline limit of no more than 10⁶ Ω for metal components to be considered safely grounded in most combustible-dust applications. The standard covers material choice, grounding methods and control measures. This is the source of the indicative resistance values used for ATEX equipment and accessories.
Source: as on our Ex-Vac wiki
International standard for the measurement and documentation of electrical properties of hoses and hose assemblies. Defines the categories antistatic (typically < 10⁹ Ω) and electrically conductive (typically < 10⁶ Ω) together with end-to-end resistance test methods. Used as the test reference in EN 17348:2022, which requires documented resistance throughout the grounding chain from the vacuum cleaner's chassis bolt through the hose to the nozzle.
Source: as on our Ex-Vac wiki
Standardised test apparatus and method for the measurement of dust explosion parameters in a 20-litre spherical test vessel. Part -1 covers maximum explosion pressure (Pmax), part -2 measures the explosion constant Kst and dKst, part -3 covers limiting oxygen concentration (LOC), and part -4 covers minimum explosible concentration (MEC). The results provide the basis for selecting the explosion-protection method (venting, suppression, isolation) and for grouping dust into the St classes St 1, St 2 and St 3.
Source: as on our Ex-Vac wiki
Defines the test method for determining the lowest energy that can ignite a dust/air mixture. MIE is typically expressed in millijoules (mJ). The result determines whether electrostatic discharges and ordinary ignition sources can trigger an explosion. For powders with MIE below 3 mJ, ESD protection and equipotential bonding are critical; for MIE below 0.1 mJ, inerting is normally required.
Source: as on our Ex-Vac wiki
Describes the sizing and placement of venting systems that protect vessels and room structures against dust explosions. Built on Pmax and Kst values measured per EN 14034. Used for sizing vent panels on large dust collectors and silos. Smaller, sealed ATEX vacuum cleaners are typically built to withstand internal explosion without venting.
Source: as on our Ex-Vac wiki
Practical guidance from the Danish Working Environment Authority on how to fulfil the requirements of BEK 478/2003. Describes in detail how to prepare an ATEX risk assessment, how to build the explosion protection document and how to select equipment matching the zone category. The guidance is not legally binding but is followed in practice by the Danish authorities during inspections.
Source: as on our Ex-Vac wiki
Consolidated guidance from the Danish Emergency Management Agency on zone classification and marking under BEK 268/2010. Includes detailed guidance on how the zone drawing is built, the applicable distance rules and how the classification is documented. Supplemented by an indicative table of typical scenarios (silos, filling rooms, conveyors) that can be used as a benchmark.
Source: as on our Ex-Vac wiki
The ATEX marking on a vacuum cleaner label states the equipment's complete explosion-protection specification on a single line. Example: II 2D Ex h tb IIIC T80°C Db. Reading: II = surface installation (not mining), 2 = category 2 (high safety, Zone 1 or 21), D = dust environment, Ex h = protection method (constructive, non-electrical), tb = electrical protection against dust (enclosure), IIIC = dust group (conductive dust — the strictest level), T80°C = maximum surface temperature, Db = Equipment Protection Level (typically Db for category 2D). The marking follows ATEX 2014/34/EU and EN ISO 80079-36/-37.
Source: as on our Ex-Vac wiki
EPL is the modern replacement for the old categories 1, 2 and 3 in the ATEX Directive. Da, Db and Dc are used for dust environments; Ga, Gb and Gc for gas environments. Da/Ga = highest safety level, required in Zone 0/20. Db/Gb = high safety, required in Zone 1/21. Dc/Gc = normal safety, required in Zone 2/22. The EPL system is internationally harmonised with IECEx and is used in modern ATEX marking. ACD vacuum cleaners are typically classified as EPL Dc internally.
Source: as on our Ex-Vac wiki
The lowest energy that can ignite a dust/air mixture or gas/air mixture, measured in millijoules (mJ). Determined for dust per EN 13821 and is one of the central parameters for classifying combustible dust and selecting the explosion protection method. MIE = electrostatic discharges can ignite — ESD protection and equipotential bonding are critical. MIE = practically all electrical and friction-based ignition sources can ignite — ATEX-approved equipment is strictly required. MIE = inerting is typically the only safe solution.
Source: as on our Ex-Vac wiki
Characteristic parameter for the violence of dust explosions, measured in bar·m/s in a 20-litre spherical test vessel per EN 14034-2. Kst expresses the nominal rate of pressure rise normalised to one cubic metre of volume. Classification: St 1 = Kst 1–200 (mild explosion, e.g. flour and sugar), St 2 = 200–300 (strong, e.g. some plastic powders), St 3 = > 300 (very strong, e.g. aluminium powder). The Kst value is used in the dimensioning of venting systems (EN 14491) and explosion-suppression systems.
Source: as on our Ex-Vac wiki
The ATEX marking entry stating the highest surface temperature the equipment can reach during normal operation or foreseeable fault conditions. For gas environments, classes T1 (450 °C max.), T2 (300 °C), T3 (200 °C), T4 (135 °C), T5 (100 °C), T6 (85 °C) are used. For dust environments the actual maximum temperature is given directly in °C, e.g. T80°C or T125°C. The T-class must be at least 75 °C below MIT-cloud and at least MIT-layer minus 75 °C for the dust in the application.
Source: as on our Ex-Vac wiki
The written documentation the employer must prepare under the ATEX Workers Directive 1999/92/EC and BEK 478/2003. Must contain the zone drawing, the risk assessment, documentation of the equipment placed in the classified zones, and an action plan for preventing and protecting against explosion. The EPD must be available during inspection by the Working Environment Authority and be updated whenever there is a substantial change in operating conditions. Note: EPD is also used as an abbreviation for Electrostatic Discharge — the context determines the meaning.
Source: as on our Ex-Vac wiki
Ask us, and we explain it for your task.
The wiki gives general explanations. ATEX zones are classified by the employer; always check the marking and the manual of your machine.
Vacuum solutions for pharma, cleanrooms and life science.
particulair.eu/life-science
Accessories for vacuum cleaners in ATEX zones and food environments.
particulair.eu/vace
ATEX and ACD vacuum cleaners for explosion-classified zones and combustible dust.
particulair.eu/ex-vac
Technical hoses for critical environments.
particulair.eu/flexcore
Vibrators, air cannons and fluidisation that make powder flow out of silos and hoppers.
particulair.eu/flow-aid
We're ready to advise on selection and sizing.