ISO/FDIS 17597

ISO/TC 142
Secretariat: UNI
Date: 2026-06-25xx
Test method for measuring in-duct airborne microorganisms
inactivation/removal effectiveness (AMIRE)
Méthode d'essai pour mesurer l'efficacité d'inactivation/d'élimination des micro-organismes en suspension
dans l’air (AMIRE) en conduit
FDIS stage
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ii
Contents
Foreword . iv
Introduction . v
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 2
4 Principle . 3
5 Test apparatus and procedures . 3
5.1 Test rig . 3
5.2 Bioaerosol injection . 4
5.3 Installation of test device . 4
5.4 Installation of bioaerosol samplers . 4
5.5 Preventing test facility contamination . 5
6 Apparatus qualification testing . 5
6.1 Duct leakage test . 5
6.2 Air velocity uniformity in the test duct . 5
6.3 Aerosol uniformity in the test duct . 5
6.4 No device correlation (penetration) test . 5
7 Bioaerosol preparation . 5
7.1 Test organisms . 5
7.2 Bioaerosol preparation and generation . 6
8 Bioaerosol testing . 6
8.1 Test air flowrate . 6
8.2 Test procedure . 6
8.3 Bioaerosol sampling procedure . 7
8.4 Test precision . 7
9 Determination of inactivation/removal effectiveness . 7
9.1 Calculation of uncorrected inactivation/removal effectiveness . 7
9.2 Correction for no device correlation (penetration) . 7
10 Test report . 8
Annex A (normative) Dust loading test for AMIRE . 11
Bibliography . 13

iii
Foreword
ISO (the International Organization for Standardization) is a worldwide federation of national standards
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This document was prepared by Technical Committee ISO/TC 142, Cleaning equipment for air and other gases.
Any feedback or questions on this document should be directed to the user’s national standards body. A
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iv
Introduction
Airborne microorganisms, including pathogens, spread readily through indoor air, and can cause a variety of
diseases. A number of removal and deactivation technologies have been developed to deal with this situation.
Relevant existing standards include ASHRAE Standard 185.1, ISO 16890, ISO 29463, ISO 10121 and
ISO 15714.
However, none of these existing standards are fully relevant for the wide variety of different technologies used
for the removal and deactivation of airborne microorganisms. In the case of ASHRAE 185.1 and ISO 15714,
the test is specified only for UV devices and does not include mechanical filtration and other technologies.
There is currently no internationally accepted method for measuring the inactivation/removal effectiveness
of air disinfection devices that are mounted in heating, ventilation and air-conditioning (HVAC) systems other
than UV-based ones.
This document provides a laboratory test method for microorganism inactivation/removal. It builds on
existing standards such as the ones listed above and broadens the scope to cover specific types of
microorganism inactivation/removal devices in air ducts.
The airborne microorganism inactivation/removal effectiveness is based on an evaluation of the ability of the
duct-mounted air-filtering devices to capture or inactivate bacteria, moulds or viruses with common particle
sizes. By measuring the inactivation/removal effectiveness, the quality level of the product can be assessed.

v
Test method for measuring in-duct airborne microorganisms
inactivation/removal effectiveness (AMIRE)
WARNING — The test given in this document shall be performed by expert staff trained and certified
to handle microorganism-related techniques. Leakage from test equipment may release
microorganisms into the laboratory air. National and international safety procedures for working with
infectious biomaterials shall be followed to prevent contamination of apparatus, working place or
environment. Microorganisms used in the tests shall be handled with caution while wearing protective
equipment suitable for biosafety level.
1 Scope
This document specifies a method that evaluates inactivation/removal effectiveness against airborne
microorganisms in air cleaning devices. This method includes detailed requirements for the test rig, and
simulates the air flow rateflowrate of the devices. The method also covers data acquisition, analysis, and
reporting of results. Additionally, this document provides a normative procedure (see Annex AAnnex A)) for
determining the effect of dust loading on the inactivation and removal effectiveness.
This document is applicable to in-duct air cleaning devices, such as air filters set up in a heating, ventilation
and air-conditioning (HVAC) system in commercial, institutional and office buildings, also in-duct air-purifying
systems, or air sterilizers in these buildings. It applies to testing conducted under controlled laboratory
conditions using specific surrogate test microorganisms (bacteria, moulds, and viruses).
This document does not apply to:
— — air cleaning devices intended for portable or standalone room use, which are addressed by ISO 16000-
36 and the IEC 63086 series;,
— — devices evaluated solely for the physical removal of non-biological particulate matter, which are
covered by the ISO 16890 series., and
— — clinical, medical, or industrial cleanroom applications requiring specific pathogenic testing.
Furthermore, it does not cover the detailed assessment of ultraviolet (UV) dose evaluation exclusively for in-
duct ultraviolet germicidal irradiation (UVGI) devices, which is covered by ISO 15714 and ASHRAE 185.1.
2 Normative Referencesreferences
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.
ISO 15957, Test dusts for evaluating air cleaning equipment
ISO 29464, Cleaning of air and other gases — Vocabulary
ISO 16890--2:2022, Air filters for general ventilation — Part 2: Measurement of fractional efficiency and air flow
resistance
ISO 16890--3:2024, Air filters for general ventilation — Part 3: Determination of the gravimetric efficiency and
the air flow resistance versus the mass of test dust captured
3 Terms and Definitionsdefinitions
For the purposes of this document, the terms and definitions given in ISO 29464 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 3.1
airborne microorganism
particle of biological origin suspended in air
Note 1 to entry: Airborne microorganisms include bacteria, fungi and their spores, and viruses.
[SOURCE: ISO 29464:2024, 3.6.12]
3.2 3.2
airborne microorganism inactivation/removal effectiveness
AMIRE
degree of reduction of culturable airborne microorganisms resulting from passage through an air cleaning
device
3.3 3.3
bioaerosol
particles of biological origin suspended in a gaseous medium
Note 1 to entry: Bioaerosol particles include viruses, bacteria, fungi, pollen, plant debris, fragments of these and their
derivatives such as endotoxins, glucans, allergens and mycotoxins.
Note 2 to entry: The size of a bioaerosol particle can be larger if it is encased within a liquid drop, for example a virus
in sputum.
[SOURCE: ISO 29464:2024, 3.2.20]
3.4 3.4
biosafety level
BSL
level of protection and containment necessary for dealing with dangerous microorganisms in a laboratory
Note 1 to entry: Levels range from BSL 1 (least protection needed) to BSL 4 (maximum protection required).
Note 2 to entry: Classification depends on infectivity, disease severity, transmission risk, and work type. See the WHO
Laboratory Biosafety Manual or CDC BMBL (Biosafety in Microbiological and Biomedical Laboratories) for details.
Note 3 to entry: Any reference to biosafety levels in this document is indicative. The actual containment requirements
shallmust follow applicable national and/or regional regulations.
3.5 3.5
CFU
colony forming unit
unit of culturable bacteria or moulds present in a sample, expressed by the number of colonies formed under
specified culture conditions
Note 1 to entry: For microorganisms in air, concentrations are usually expressed as colony forming units per cubic
metre of air sampled (CFU/m ).
3.6 3.6
air flow rateflowrate
volume of the air passing through the air cleaning device per unit time.
Note 1 to entry: The flow rateflowrate is defined as quotient of the amount of air passing through a specified plane and
the duration.
3.7 3.7
PFU
plaque forming unit
unit of culturable viruses present in a sample, as determined by their ability to form plaques under specified
culture conditions
Note 1 to entry: For viruses in air, concentrations are usually expressed as plaque forming units per cubic metre of air
sampled (PFU/m ).
3.8 3.8
test device
air cleaner being subjected to performance testing
Note 1 to entry: ’air cleaners’ "Air cleaners" refers to air filters set up in a heating, ventilation and air-conditioning
(HVAC) system and commercial, institutional and office buildings air-purifying systems, or air sterilizers.
[SOURCE: ISO 29464:2024, 3.1.45, modified –— Note 1 to entry has been added. Terms "device under test"
and "DUT" have been removed].]
3.9 3.9
test rig
complete assembly of equipment used for determining performance of an air cleaner
4 Principle
This test method determines the performance of an air cleaner capable of inactivating or removing airborne
microorganisms in a duct or HVAC system by measuring the microorganisms upstream and downstream of
the test device.
The test device can physically remove microorganisms from the air or can cause damage sufficient to prevent
reproduction of sampled microorganisms (inactivation) or both in parallel.
This test is carried out in a large test rig of approximately 600 mm × 600 mm (2 feetft × 2 feetft). The test rig
required for conducting this test is described in Clause 5Clause 5.
5 Test apparatus and procedures
5.1 Test Rigrig
The test rig used for this document shall conform withto the requirements of the ISO 16890-2 test rig, except
as noted in this Clause 5 clause. A schematic diagram of the test rig is shown in Figure 1Figure 1. The minimum
length of each section where the test rig is separated is shown. The length of the test rig should be designed to
meet the bioaerosol concentration described in 7.27.2.
17597_ed2fig1.EPS
Dimensions in millimetres
Key
1 upstream HEPA filtration with turbulence damping grid to provide clean air
2 test microorganism generation
3 upstream microorganism sampling port
4 upstream test filter pressure tap
5 test device
6 downstream test filter pressure tap
7 downstream microorganism sampling port
8 downstream HEPA filtration with turbulence damping grid to prevent particle from escaping out of the duct
9 example of air flow measurement device location
10 example of sampling holes for duct airflow uniformity
Figure 1 — Schematic diagram of the test rig
5.2 Bioaerosol injection
Bioaerosol shall be injected at the location indicated by item 2 in Figure 1Figure 1. The bioaerosol injection
system shall produce an upstream challenge bioaerosol that meets the qualification criteria of 7.27.2. The
injection system design is described in 7.27.2.
5.3 Installation of test device
Installation of the test device shall comply withconform to the instructions of the equipment manual. The test
device shall be sealed into the test rig in a manner that prevents leakage between the test device and the
mounting frame.
5.4 Installation of bioaerosol samplers
One or more bioaerosol samplers shall be installed upstream of the test device, and downstream of the device.
These samplers shall be collocated with the probes specified in ISO 16890-2. If multiple samplers are used,
they shall be located so that the inlet air streams do not interfere with each other. The inlets of the bioaerosol
samplers shall face into the airflow. Isokinetic sampling (to within 10 % of a measured target flow velocity as
measured by the instruments indicated) shall be used. Flow rateFlowrate through the sampling system shall
be measured with volumetric devices such as orifice plates or rotameters having an accuracy of ±5 %. Samples
and devices shall be located such that the air cleaning device does not influence the upstream sampling
location. A light baffle or extra distance can be needed for some d
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