oSIST prEN 14175-9:2026

• Abstract:

  This document specifies characteristics concerning the design and performance requirements together with type testing and on-site testing procedures especially for ducted filtration fume cupboards (DFFCs) not described in the other parts of EN 14175. Filters in DFFCs can be specific filters or a combination of filters dependent on the characteristics of the contaminants to be removed. ; This part of EN 14175 is related to and refers to other parts of EN 14175 regarding definitions, technologies, testing methodologies, design factors and functional aspects and is read in conjunction with these.; This standard covers the specific layout version of ducted fume cupboards with integral filtration. These devices called ducted filtration fume cupboards can be designed to partially reuse filtered air for internal dilution. Therefore, the term “hybrid” fume cupboards is sometimes used.; Fume cupboards with associated filters are considered as standard fume cupboards according EN 14175 1 to EN 14175 3. ; NOTE Their filter requirements, description and testing are listed in Annex A for information.; The requirements for fume cupboards and filters for radioactive work are described in detail in EN 14175 8.; Recirculatory filtration fume cabinets which return the filtered exhaust air back into the surrounding room are not part of this document but described in prEN 17242.; DFFCs are not foreseen for work with pathogens. Appropriate microbiological cabinets are described in the EN 12469 series.

• Status: Not Published
• Public Enquiry End Date: 30-Jul-2026
• ICS: 71.040.10 - Chemical laboratories. Laboratory equipment
• Technical Committee: I13 - Imaginarni 13
• Current Stage: 4020 - Public enquire (PE) (Adopted Project)
• Start Date: 25-May-2026
• Due Date: 12-Oct-2026
• Completion Date: 03-Aug-2026
• Ref Project: prEN 14175-9 - Fume cupboards — Part 9: Fume cupboards, ducted with filtered internal recirculation

oSIST prEN 14175-9:2026 is a draft European standard published through SIST for fume cupboards with ducted filtration and filtered internal recirculation. It specifies design and performance requirements, together with type testing and on-site testing procedures, for Ducted Filtration Fume Cupboards (DFFC) used to protect the operator and the external environment.

What does oSIST prEN 14175-9:2026 specify?

oSIST prEN 14175-9:2026 covers the specific layout of ducted fume cupboards with integral filtration, where part of the filtered air may be reused inside the cupboard. Clause 1 sets the focus on DFFC that are not described in the other parts of EN 14175, and it ties this part to the rest of the series for definitions, technologies, testing methods, design factors and functional aspects.

The scope also makes clear what belongs elsewhere. Recirculatory filtration fume cabinets that return filtered exhaust air to the room are covered by prEN 17242, radioactive work is covered by EN 14175-8, and work with pathogens is addressed by EN 12469.

Annex	What it covers
Annex A	Filter systems used with fume cupboards, including example filter principles and applications

What are the key requirements of oSIST prEN 14175-9:2026?

Clause 4 is the core of oSIST prEN 14175-9:2026. It sets the design, monitoring, testing and reporting expectations that matter in practice when a DFFC is selected, commissioned, used and maintained.

• Design must be based on the contamination risk and the work process. Clause 4.1 says the filter type, the intended use and the materials handled have to fit the risk assessment and manufacturer’s recommendation. In practice, this means the cupboard and its filters are chosen for the actual chemicals, dusts, gases or vapours being used, not as a generic solution.

• The operator must be able to see what the filtration system is for. Clause 4.1 requires the type of filters and their intended use to be clearly visible in front of the cupboard. That matters because the person using the cupboard needs to know which tasks are allowed and when the filtration system is approaching its limits.

• Continuous monitoring and alarms are expected for filter performance. Clause 4.2 calls for monitoring and alarms for active carbon saturation or retention, and for particle-filter pressure drop where appropriate. In practice, this supports earlier action before capture efficiency or air flow falls below what the process needs.

• Air flow monitoring has to reflect the DFFC layout. Clause 4.3 says that if an air curtain is used, the inflow, total filtered air and extract air volume flows must be monitored and determined. This matters because DFFC can reuse part of the filtered air, so a single flow reading is not enough to judge containment.

• Type testing and on-site testing use several test routes. Clause 4.4 points to the test methods of EN 14175-2, EN 14175-3 and EN 14175-4, and adds DFFC-specific procedures. For type testing, three procedures are required: the standard SF6 test, the adapted SF6 test without internal SF6 enrichment, and the additional IPA containment test. For on-site testing, the IPA containment test can be repeated to compare site results with the type test.

• The additional containment performance test is a central DFFC method. Clause 4.4.7 combines static containment and dynamic robustness in one pass using IPA, a moving dummy and multiple sampling probes. The test records baseline stability, gas build-up, movement phases and purge time, which gives a practical picture of how the cupboard behaves during realistic operator motion.

• Filter-specific checks depend on the filter type. Clause 4.4.8 requires HEPA integrity testing, AC filter retention testing with IPA, suitable testing for HEPA/AC combinations, and special challenge tests for specially treated media. This matters because a DFFC may use several filter principles in sequence, and each one needs its own verification.

• Documentation and marking are part of safe use. Clauses 5 and 6 require a product manual with filter selection guidance, replacement procedure, service life, storage conditions, maintenance instructions and a logbook record. Marking must show work opening height, the tested containment performance level and the filter type, with colour band identification for filters. That helps users, maintenance staff and buyers verify correct use after installation and after filter changes.

What terms does oSIST prEN 14175-9:2026 define?

oSIST prEN 14175-9:2026 defines the key terms that set the boundary between DFFC and other fume cupboard types.

• Ducted Filtration Fume Cupboard (DFFC) - a ducted fume cupboard with integrated filters that allows internal recirculation of part of the air as make-up air.
• Integral filtration system - a filtration system built into the cupboard as a coherent, self-contained unit.
• Associated filtration system - a separate filtration system in the ductwork between the cupboard and the discharge point.
• Air curtain - an additional air-flow barrier at the front opening that supports containment.
• Prefilter - an initial filter stage used to protect or improve downstream filter components.
• Safe change of filters - provisions for safe replacement and disposal of filters and prefilters to reduce exposure of maintenance staff.
• Containment performance test - a procedure that combines predetermined process steps to evaluate containment, robustness and air exchange efficiency in one pass.

Who uses oSIST prEN 14175-9:2026?

oSIST prEN 14175-9:2026 is used by people who specify, design, manufacture, test, install, commission and maintain laboratory fume cupboards in chemical laboratories. It is also relevant to quality managers, safety managers and buyers who need to check that a DFFC matches the intended chemicals, the ventilation conditions and the required monitoring and documentation.

Operators use it indirectly through the front marking, filter identification and manual information. Test laboratories and service teams use it for type tests, on-site tests, filter checks and alarm verification. Maintenance staff use it for safe filter change, logbook records and periodic performance checks.

Which standards are used with oSIST prEN 14175-9:2026?

oSIST prEN 14175-9:2026 is read together with several other standards in the EN 14175 series and with related documents for excluded cases.

• EN 14175-1 - vocabulary for fume cupboards.
• EN 14175-2:2003 - safety and performance requirements, including flow monitoring and sash alarm provisions.
• EN 14175-3:2019 - type test methods, including the SF6 and IPA-based containment procedures.
• EN 14175-4 - on-site test methods.
• EN 14175-6 - variable air volume fume cupboards.
• EN 14175-7 - fume cupboards for high heat and acidic load.
• EN 14175-8 - fume cupboards for work with radioactive materials.
• prEN 17242 - recirculatory filtration fume cabinets that return filtered exhaust air to the room.
• EN 12469 - microbiological safety cabinets for work with pathogens.
• CEN/TS 17441 - laboratory ventilation guidance that is noted as helpful for DFFC selection.

What does the oSIST prEN 14175-9:2026 document contain?

The document contains the technical framework for DFFC design and use, plus detailed test and reporting provisions. It includes two schematic figures showing DFFC concepts, one with partial filtered-air return and one with an air curtain at the sash opening.

Clause 4 contains the test methods, including the adapted SF6 arrangement for type testing and the IPA-based containment performance test with a moving dummy. The test sequence, sampling layout and data analysis steps are described so that results can be compared at commissioning and during later checks.

Annex A provides an informative overview of filter system principles and applications, such as particulate filters, electrostatic precipitators, cyclones, adsorptive filters with activated carbon, reactive filtration, absorbers, washers and scrubbers. The annex is useful when selecting a filter strategy for dusts, solvents, acids, bases, amines or specific chemicals.

SLOVENSKI STANDARD
01-julij-2026
Digestoriji - 9. del: Digestoriji, opremljeni s filtriranim notranjim kroženjem zraka
Fume cupboards - Part 9: Fume cupboards, ducted with filtered internal recirculation
Abzüge - Teil 9: Abzüge, kanalisiert mit interner gefilterter Umwälzung
Sorbonnes - Partie 9 : Sorbonnes à recirculation partielle de l'air
Ta slovenski standard je istoveten z: prEN 14175-9
ICS:
71.040.10 Kemijski laboratoriji. Chemical laboratories.
Laboratorijska oprema Laboratory equipment
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

DRAFT
EUROPEAN STANDARD
NORME EUROPÉENNE
EUROPÄISCHE NORM
May 2026
ICS
English Version
Fume cupboards - Part 9: Fume cupboards, ducted with
filtered internal recirculation
EN 14175-9: Sorbonnes - Partie 9: Sorbonnes à filtres EN 14175-9: Laborabzüge - Teil 9: Angeschlossene
raccordées Filterlaborabzüge
This draft European Standard is submitted to CEN members for enquiry. It has been drawn up by the Technical Committee
CEN/TC 332.
If this draft becomes a European Standard, CEN members are bound to comply with the CEN/CENELEC Internal Regulations
which stipulate the conditions for giving this European Standard the status of a national standard without any alteration.

This draft European Standard was established by CEN in three official versions (English, French, German). A version in any other
language made by translation under the responsibility of a CEN member into its own language and notified to the CEN-CENELEC
Management Centre has the same status as the official versions.

CEN members are the national standards bodies of Austria, Belgium, Bulgaria, Croatia, Cyprus, Czech Republic, Denmark, Estonia,
Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway,
Poland, Portugal, Republic of North Macedonia, Romania, Serbia, Slovakia, Slovenia, Spain, Sweden, Switzerland, Türkiye and
United Kingdom.
Recipients of this draft are invited to submit, with their comments, notification of any relevant patent rights of which they are
aware and to provide supporting documentation.

Warning : This document is not a European Standard. It is distributed for review and comments. It is subject to change without
notice and shall not be referred to as a European Standard.

EUROPEAN COMMITTEE FOR STANDARDIZATION
COMITÉ EUROPÉEN DE NORMALISATION

EUROPÄISCHES KOMITEE FÜR NORMUNG

CEN-CENELEC Management Centre: Rue de la Science 23, B-1040 Brussels
© 2026 CEN All rights of exploitation in any form and by any means reserved Ref. No. prEN 14175-9:2026 E
worldwide for CEN national Members.

Contents Page
European foreword . 3
Introduction . 4
1 Scope . 5
2 Normative references . 5
3 Terms and definitions . 6
4 Requirements for ducted filtration fume cupboards . 7
4.1 General. 7
4.2 Filter monitoring and alarms . 10
4.3 Additional air flow monitoring . 10
4.4 Test methods . 10
4.4.1 General. 10
4.4.2 Face velocity test . 11
4.4.3 Sash Position alarm test . 11
4.4.4 Pressure drop test . 11
4.4.5 Extract air volume flow rate test . 11
4.4.6 Workspace air volume flow . 11
4.4.7 Additional Containment performance test . 12
4.4.8 Filter tests . 15
4.4.9 Filter pressure drop test . 16
4.4.10 Filter differential pressure test . 16
4.4.11 Tests of monitoring and alarms . 16
4.4.12 Reporting of filter tests . 17
5 Product manual and documentation . 17
6 Marking and labelling . 17
Annex A (informative) Filter systems in use with fume cupboards. 19
Bibliography . 20

European foreword
This document (prEN 14175-9:2026) has been prepared by Technical Committee CEN/TC 332
“Laboratory equipment”, the secretariat of which is held by DIN.
This document is currently submitted to the CEN Enquiry.
Introduction
Ducted Filtration Fume Cupboards (DFFC) are especially adapted devices intended to protect their users
and/or the external environment by means of:
— The ability to contain potentially hazardous materials.
— The ability to remove potentially hazardous materials from air exhausted from within the fume
cupboard housing by means of filtration before the air is discharged to the external environment.
The protection of operators is the main purpose of fume cupboards. As health risks are rising from more
and more potent hazardous products, additional barriers may be necessary. Regarding the installation
sites of cupboards there are growing efforts to improve environmental protection by additional filtration
of contaminated air directly at the source. As dilution is not a solution to pollution, the intention is to
minimise the discharge of contaminants into the atmosphere as well as to protect the exhaust air system,
to make the maintenance safer of this, and to prevent burden to the public environment. Use of filtration
also reduces the potential for re-entrainment of contaminated exhaust air through the air intakes. With
the possibility of partial filtered air reuse such ducted fume cupboards may reduce the volume of exhaust
air discharged. So, they may serve as an alternative solution, where building make up air ventilation is at
capacity limit, contributing to climate protection and energy saving.
The types of potentially hazardous materials to be removed include particulates, gases, vapours, aerosols,
and combinations of these. This objective is driven by aspects of performance based on health risks,
nuisance effects, environmental impacts, or a combination of these. The guidance for filter use is based
upon an operator risk assessment considering particulate or chemical hazards and work processes.
1 Scope
This document specifies characteristics concerning the design and performance requirements together
with type testing and on-site testing procedures especially for ducted filtration fume cupboards not
described in the other parts of EN 14175. Filter in DFFCs can be specific filters or a combination of filters
dependent on the characteristics of the contaminants to be removed.
This document is related to and will refer to other parts of EN 14175 regarding definitions, technologies,
testing methodologies, design factors and functional aspects.
This document covers the specific layout version of ducted fume cupboards with integral filtration. These
devices called Ducted Filtration Fume Cupboards (DFFC) may be designed to partially reuse filtered air
for internal dilution.
Fume cupboards fitted with filters which only act on the extracted air stream are not covered by this part.
Their filter requirements, description and testing could be taken from this standard, in particular in
Annex A.
Recirculatory Filtration Fume Cabinets which return the filtered exhaust air back into the surrounding
room are not part of this standard but described in the EN 17242.
The requirements for fume cupboards and filters for radioactive work are described in detail in
EN 14175-8.
DFFCs are not foreseen for work with pathogens. Appropriate microbiological cabinets are described in
EN 12469.
2 Normative references
The following documents are referred to in the text in such a way that some or all of their content
constitutes requirements of this document. For dated references, only the edition cited applies. For
undated references, the latest edition of the referenced document (including any amendments) applies.
EN 14175-1, Fume cupboards – Part 1: Vocabulary
EN 14175-2:2003, Fume cupboards - Part 2: Safety and performance requirements
EN 14175-3:2019, Fume cupboards - Part 3: Type test methods
EN 14175-4, Fume cupboards – Part 4 : On-site test methods
EN 14175-6, Fume cupboards – Part 6 : Variable air volume fume cupboards
EN 14175-7, Fume cupboards – Part 7: Fume cupboards for high heat and acidic load
EN 14175-8, Fume cupboard – Part 8: Fume cupboards for work with radioactive materials
3 Terms and definitions
For the purposes of this document, the terms and definitions given in EN 14175 (all parts), and the
following apply.
ISO and IEC maintain terminology databases for use in standardization at the following addresses:
— ISO Online browsing platform: available at https://www.iso.org/obp/
— IEC Electropedia: available at https://www.electropedia.org/
3.1
air curtain
additional (for instance vertical) air flow barrier in the front opening of a fume cupboard to support
containment efficiency in separating the inside from the outside of the workspace
3.2
filter
container or a frame containing a collecting filter medium to separate and trap impurities or solid
particles from a liquid or gases passed through it
3.3
filtration system
assembly of one or more filter components or devices that are used to remove/trap airborne
contaminants, including filter, fittings, seals and other connecting parts
Note 1 to entry: A non-exclusive list of types may include one or several particulate filters, chemical absorptive and
physical adsorptive filters (such as e.g., activated carbon), electrostatic precipitators, cyclones, washers, and
scrubbers; see Annex A.
3.4
integral filtration system
filtration system that is fully integrated into the construction of a fume cupboard insofar as it can be
regarded as a coherent, self-contained unit
Note 1 to entry: Fume cupboards with integral filtration systems may also be connected to associated filtration
systems.
3.5
associated filtration system
filtration system that is separate from, but associated with, a fume cupboard and is in the ductwork
between the fume cupboard(s) and the point of discharge from the laboratory
3.6
Ducted Filtration Fume Cupboard
DFFC
ducted fume cupboard equipped with integrated filters to enable internal recirculation of the air as part
of the make up air
3.7
prefilter
initial filtering stage used to remove particulates and/or gases/vapours to protect or improve other
components (e.g. of a filtration system) having higher removal efficiencies
3.8
extract air flow control arrangement
an installation, a control system or sub-system to provide consistent extract air flow conditions
3.9
‘Safe change’ of filters
provisions that allow safe replacement and disposal of filters and prefilters to reduce potential exposure
(e.g., inhalation, skin contact contamination) of the maintenance operator to potentially harmful material
or conditions
3.10
plenum
enclosure part of fume cupboards and cabinets, connected on the one hand to a filter system and on the
other hand to an air supply or an extract air system to isolate zones of air volumes of different pressure
levels
3.11
draught
uncontrolled air flow pattern, directed or turbulent, interfering with intended flow pattern
Note 1 to entry: As a result, draughts may influence the containment performance of fume cupboards.
Note 2 to entry: Low and high temperature draughts (e.g. from air conditioning or ceiling outlets) are often
particularly influential.
3.12
containment
resistance to egress or ingress of contents
Note 1 to entry: A device with containment is a containment enclosure.
3.13
containment performance test
specific test procedure to test the containment performance with a sequence of predetermined process
steps to evaluate containment, robustness, and air exchange efficiency in one pass
4 Requirements for ducted filtration fume cupboards
4.1 General
Fume cupboards (FC) with associated filtration systems are devices complying with EN 14175-2. They
are particularly characterised by the fact that they discharge all air exhausted from within them to the
duct after being filtered to reduce the levels of potential contaminants.
Ducted filtration fume cupboards (DFFC) have a layout with integral filters combined with partial internal
reuse of filtered air. For a schematic example, see figure 1. An overview of different filter systems is found
in the Annex A.
A variety of functional objectives may be addressed using a DFFC including:
— reduction in concentration of materials discharged that potentially present health risks;
— reduction in the level of contamination to exhaust ductwork installations;
— reduction in environmental impact of the fumes discharged;
— reduction in concentration of materials discharged that may represent a nuisance (odour, dust,
particulates as examples);
— protection from spillage effects;
— to overcome capacity limitations of air extract systems;
— energy savings.
The specific layout is characterised by the fact that all air volume flow to the exhaust is filtered before
discharge to the natural environment and thereby protecting it. A partial fraction of the filtered air
volume, e.g. 50 %, may be returned to the workspace within the fume cupboard to support retention of
contaminants. This principle may require or be supported by integral fans to overcome the pressure drop
of the filters and/or serve additional purposes.

Key
1 filtered exhaust air
2 filtered air
3 filtered air, returned to workspace as air curtain
4 potentially contaminated air
5 sash
6 supply air
7 workspace air volume flow
8 filter(s)
9 plenum for filtered air
10 fan
flow path of filtered air
flow path of supply air
potentially contaminated air
Figure 1 — Example for a DFFC concept
Solid arrows show the extraction of potentially contaminated air from the workspace through filters
underneath the work surface. The grey dashed arrows demonstrate the flow paths of the filtered air: One
fraction of the filtered air is released to duct and the other fraction returns to the workspace within the
fume cupboard envelope. Filter(s) may be positioned elsewhere within the overall envelope of the DFFC.
The specific requirements for DFFCs result from above concept example and shall be based on a risk
assessment and manufacturers recommendation. This could include:
— categories and quantities of chemicals being handled;
— special demands for retention of contaminants and containment;
— air flow capacities of the lab ventilation;
— filtration system and type;
— filter change procedure (Safe change of filters);
— sampling or filter testing;
— containment performance class of the fume cupboard.
NOTE CEN/TS 17441 “Ventilation systems in laboratories” can be a helpful reference.
The type of filters installed, and their intended use must always be clearly visible to the operator in front
of the fume cupboard.
DFFCs may have low face velocities and use an air curtain by design to improve the operator’s protection
at the work opening (see figure 2).

Key
1 potentially contaminated air
2 sash
3 supply air
4 air curtain
5 work surface
6 workspace air volume flow
flow path of filtered air
flow path of supply air
potentially contaminated air
Figure 2 — Example for a DFFC sash opening equipped with air curtain
The light grey dashed arrows demonstrate the flow path of the vertical air curtain to the work surface.
Dark grey solid arrows show the extraction of potentially contaminated air underneath the work surface.
4.2 Filter monitoring and alarms
Certain types of filters will have air flow resistances that increase with use, most typically due to
particulate loading of the filter media. Such increase in resistance is likely to affect (reduce) volume flow
rates of DFFCs. Active carbon filters are loaded with chemicals reducing their capture capacity and
efficiency as is the stripping agent in washers/scrubbers. Therefore, DFFCs should include continuous
monitoring and alarm(s) for:
— filter retention or saturation of active carbon filter(s), e.g. with solvent sensor or PID;
— filter pressure drop for particle filters, where appropriate;
— filters are an integral part of DFFCs and should be subject to regular maintenance and testing as part
of local safety regulations and manufacturer’s recommendations.
NOTE Other filter systems (see Annex A) can require additional items to be monitored (e.g. stripping liquid of
washers, e.g. with photometer or pH-meter).
4.3 Additional air flow monitoring
If the DFFC is equipped with an air curtain in the front opening, the efficiency of it is depending on the
airflow balance between inflow and downflow. An air curtain is fragile by design and may react
sensitively to draughts. The correct function of it assures the containment and therefore, it shall be
measured with a robustness test or containment test, e.g. see 4.3.6. Both the values of the total filtered
air volume and extract air volume flows must be monitored and determined alternatively.
The monitoring of the inflow, total filtered and extract air volume flow rates shall be in accordance with
EN 14175-2:2003, 8.2.
4.4 Test methods
4.4.1 General
The test methods of EN 14175-2, EN 14175-3 and EN 14175-4 apply.
Due to the specific characteristics of DFFCs some of the standard test methods need to be more detailed
hereafter. If the respective containment tests cannot be performed accordingly due to the fume cupboard
design and/or filter materials used an adapted testing described under 4.4.7 or additional containment
performance test described under 4.4.8 hereafter shall be carried out.
For the type testing of DFFC three test procedures shall be conducted in a type test laboratory according
to EN 14175-3:2019, Clause 4:
• the s
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