Nanomaterials - Quantification of nano-object release from powders by generation of aerosols (ISO/TS 12025:2021)

This document describes methods for the quantification of nano-object release from powders as a
result of treatment, ranging from handling to high energy dispersion, by measuring aerosols liberated
after a defined aerosolization procedure. Particle number concentration and size distribution of the
aerosol are measured and the mass concentration is derived. This document provides information
on factors to be considered when selecting among the available methods for powder sampling and
treatment procedures and specifies minimum requirements for test sample preparation, test protocol
development, measuring particle release and reporting data. In order to characterize the full size range
of particles generated, the measurement of nano-objects as well as agglomerates and aggregates is
adressed in this document.
This document does not include the characterization of particle sizes within the powder. Tribological
methods are excluded where direct mechanical friction is applied to grind or abrade the material.

Nanomaterialien - Quantifizierung der Freisetzung von Nanoobjekten aus Pulvern durch Aerosolerzeugung (ISO/TS 12025:2021)

Dieses Dokument beschreibt Verfahren zur Quantifizierung der Nanoobjekt-Freisetzung aus Pulvern als Ergebnis des gesamten Verfahrens, vom Handling bis zu hoch-energetischer Dispergierung, durch Messung des entstehenden Aerosols nach definierter Pulverbeanspruchung. Partikelanzahlkonzentration und  größenverteilung des Aerosols werden gemessen und die Massenkonzentration abgeleitet. Dieses Dokument liefert Angaben über zu beachtende Faktoren bei der Auswahl unter den zur Verfügung stehenden Verfahren zur Probennahme als auch der Beanspruchung und legt Mindestanforderungen an die Probenherstellung, die Erarbeitung des Prüfprotokolls, die Messung der Partikelfreisetzung und die anzugebenden Daten fest. Damit der vollständige Größenbereich der erzeugten Partikel beschrieben werden kann, wird in diesem Dokument neben der Messung von Nanoobjekten auch die Messung von Agglomeraten und Aggregaten empfohlen.
Dieses Dokument behandelt nicht die Charakterisierung von Partikelgrößen innerhalb des Pulvers. Tribologische Verfahren, bei denen das Material mittels direkter mechanischer Reibung bearbeitet wird, um es abzureiben oder zu schleifen, sind von dieser Technischen Spezifikation ausgenommen.

Nanomatériaux - Quantification de la libération de nano-objets par les poudres par production d'aérosols (ISO/TS 12025:2021)

Nanomateriali - Kvantifikacija sproščanja nanoobjektov iz prahu s proizvodnjo aerosola (ISO/TS 12025:2021)

General Information

Status
Published
Public Enquiry End Date
27-Dec-2020
Publication Date
16-Jun-2021
Technical Committee
Current Stage
6060 - National Implementation/Publication (Adopted Project)
Start Date
10-Jun-2021
Due Date
15-Aug-2021
Completion Date
17-Jun-2021

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SLOVENSKI STANDARD
SIST-TS CEN ISO/TS 12025:2021
01-september-2021
Nadomešča:
SIST-TS CEN ISO/TS 12025:2015
Nanomateriali - Kvantifikacija sproščanja nanoobjektov iz prahu s proizvodnjo
aerosola (ISO/TS 12025:2021)

Nanomaterials - Quantification of nano-object release from powders by generation of

aerosols (ISO/TS 12025:2021)

Nanomaterialien - Quantifizierung der Freisetzung von Nanoobjekten aus Pulvern durch

Aerosolerzeugung (ISO/TS 12025:2021)

Nanomatériaux - Quantification de la libération de nano-objets par les poudres par

production d'aérosols (ISO/TS 12025:2021)
Ta slovenski standard je istoveten z: CEN ISO/TS 12025:2021
ICS:
07.120 Nanotehnologije Nanotechnologies
SIST-TS CEN ISO/TS 12025:2021 en,fr,de

2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

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SIST-TS CEN ISO/TS 12025:2021
---------------------- Page: 2 ----------------------
SIST-TS CEN ISO/TS 12025:2021
CEN ISO/TS 12025
TECHNICAL SPECIFICATION
SPÉCIFICATION TECHNIQUE
June 2021
TECHNISCHE SPEZIFIKATION
ICS 07.120 Supersedes CEN ISO/TS 12025:2015
English Version
Nanomaterials - Quantification of nano-object release from
powders by generation of aerosols (ISO/TS 12025:2021)

Nanomatériaux - Quantification de la libération de Nanomaterialien - Quantifizierung der Freisetzung von

nano-objets par les poudres par production d'aérosols Nanoobjekten aus Pulvern durch Aerosolerzeugung

(ISO/TS 12025:2021) (ISO/TS 12025:2021)

This Technical Specification (CEN/TS) was approved by CEN on 29 January 2021 for provisional application.

The period of validity of this CEN/TS is limited initially to three years. After two years the members of CEN will be requested to

submit their comments, particularly on the question whether the CEN/TS can be converted into a European Standard.

CEN members are required to announce the existence of this CEN/TS in the same way as for an EN and to make the CEN/TS

available promptly at national level in an appropriate form. It is permissible to keep conflicting national standards in force (in

parallel to the CEN/TS) until the final decision about the possible conversion of the CEN/TS into an EN is reached.

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, Turkey and

United Kingdom.
EUROPEAN COMMITTEE FOR STANDARDIZATION
COMITÉ EUROPÉEN DE NORMALISATION
EUROPÄISCHES KOMITEE FÜR NORMUNG
CEN-CENELEC Management Centre: Rue de la Science 23, B-1040 Brussels

© 2021 CEN All rights of exploitation in any form and by any means reserved Ref. No. CEN ISO/TS 12025:2021 E

worldwide for CEN national Members.
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SIST-TS CEN ISO/TS 12025:2021
CEN ISO/TS 12025:2021 (E)
Contents Page

European foreword ....................................................................................................................................................... 3

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SIST-TS CEN ISO/TS 12025:2021
CEN ISO/TS 12025:2021 (E)
European foreword

This document (CEN ISO/TS 12025:2021) has been prepared by Technical Committee ISO/TC 229

"Nanotechnologies" in collaboration with Technical Committee CEN/TC 352 “Nanotechnologies” the

secretariat of which is held by AFNOR.

Attention is drawn to the possibility that some of the elements of this document may be the subject of

patent rights. CEN shall not be held responsible for identifying any or all such patent rights.

This document supersedes CEN ISO/TS 12025:2015.

According to the CEN-CENELEC Internal Regulations, the national standards organizations of the

following countries are bound to announce this Technical Specification: 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, Turkey and the

United Kingdom.
Endorsement notice

The text of ISO/TS 12025:2021 has been approved by CEN as CEN ISO/TS 12025:2021 without any

modification.
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SIST-TS CEN ISO/TS 12025:2021
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SIST-TS CEN ISO/TS 12025:2021
TECHNICAL ISO/TS
SPECIFICATION 12025
Second edition
2021-05
Nanomaterials — Quantification of
nano-object release from powders by
generation of aerosols
Nanomatériaux — Quantification de la libération de nano-objets par
les poudres par production d'aérosols
Reference number
ISO/TS 12025:2021(E)
ISO 2021
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SIST-TS CEN ISO/TS 12025:2021
ISO/TS 12025:2021(E)
COPYRIGHT PROTECTED DOCUMENT
© ISO 2021

All rights reserved. Unless otherwise specified, or required in the context of its implementation, no part of this publication may

be reproduced or utilized otherwise in any form or by any means, electronic or mechanical, including photocopying, or posting

on the internet or an intranet, without prior written permission. Permission can be requested from either ISO at the address

below or ISO’s member body in the country of the requester.
ISO copyright office
CP 401 • Ch. de Blandonnet 8
CH-1214 Vernier, Geneva
Phone: +41 22 749 01 11
Email: copyright@iso.org
Website: www.iso.org
Published in Switzerland
ii © ISO 2021 – All rights reserved
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SIST-TS CEN ISO/TS 12025:2021
ISO/TS 12025:2021(E)
Contents Page

Foreword ........................................................................................................................................................................................................................................iv

Introduction ..................................................................................................................................................................................................................................v

1  Scope ................................................................................................................................................................................................................................. 1

2  Normative references ...................................................................................................................................................................................... 1

3  Terms and definitions ..................................................................................................................................................................................... 1

3.1 General terms .......................................................................................................................................................................................... 1

3.2 Terms related to particle properties and measurement ..................................................................................... 2

4  Symbols .......................................................................................................................................................................................................................... 5

5  Factors influencing results of nano-object release from powders ...................................................................5

5.1 Test generation method selection .......................................................................................................................................... 5

5.2 Material properties influencing nano-object release from powder .......................................................... 5

5.3 Test stages ................................................................................................................................................................................................... 6

6 Test requirements ............................................................................................................................................................................................... 7

6.1 General ........................................................................................................................................................................................................... 7

6.2 Safety assessment ................................................................................................................................................................................. 7

6.3 Sample preparation ............................................................................................................................................................................ 8

6.4 Sample treatment ................................................................................................................................................................................. 8

6.4.1 Dustiness generation methods ............................................................................................................................ 8

6.4.2 Dispersing methods for aerosol generation ............................................................................................. 9

6.4.3 Sample treatment execution and report ..................................................................................................... 9

6.5 Measurement of aerosolized nano-objects ..................................................................................................................10

6.5.1 Selection of the measuring method ..............................................................................................................10

6.5.2 Transport and sampling parameters ...........................................................................................................11

6.5.3 Considerations before testing ............................................................................................................................12

6.5.4 Size and concentration measurement results .....................................................................................12

6.5.5 Particle size distribution and other characteristic measurement parameters .......14

7  Requirements for test setups and protocols ........................................................................................................................15

8  Test report ................................................................................................................................................................................................................16

Annex A (informative) Considerations for the selection of the sample treatment procedure ..............17

Annex B (informative) Dustiness reference test methods ..........................................................................................................19

Annex C (informative) Dynamic method .......................................................................................................................................................22

Annex D (informative) Dispersing methods ..............................................................................................................................................26

Annex E (informative) Selection of the nano-object measuring method .....................................................................27

Annex F (informative) Dry dispersion intensity in measuring devices .........................................................................29

Bibliography .............................................................................................................................................................................................................................30

© ISO 2021 – All rights reserved iii
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SIST-TS CEN ISO/TS 12025:2021
ISO/TS 12025:2021(E)
Foreword

ISO (the International Organization for Standardization) is a worldwide federation of national standards

bodies (ISO member bodies). The work of preparing International Standards is normally carried out

through ISO technical committees. Each member body interested in a subject for which a technical

committee has been established has the right to be represented on that committee. International

organizations, governmental and non-governmental, in liaison with ISO, also take part in the work.

ISO collaborates closely with the International Electrotechnical Commission (IEC) on all matters of

electrotechnical standardization.

The procedures used to develop this document and those intended for its further maintenance are

described in the ISO/IEC Directives, Part 1. In particular, the different approval criteria needed for the

different types of ISO documents should be noted. This document was drafted in accordance with the

editorial rules of the ISO/IEC Directives, Part 2 (see www .iso .org/ directives).

Attention is drawn to the possibility that some of the elements of this document may be the subject of

patent rights. ISO shall not be held responsible for identifying any or all such patent rights. Details of

any patent rights identified during the development of the document will be in the Introduction and/or

on the ISO list of patent declarations received (see www .iso .org/ patents).

Any trade name used in this document is information given for the convenience of users and does not

constitute an endorsement.

For an explanation of the voluntary nature of standards, the meaning of ISO specific terms and

expressions related to conformity assessment, as well as information about ISO’s adherence to the

World Trade Organization (WTO) principles in the Technical Barriers to Trade (TBT), see www .iso .org/

iso/ foreword .html.

This document was prepared by Technical Committee ISO/TC 229, Nanotechnologies, in collaboration

with the European Committee for Standardization (CEN) Technical Committee CEN/TC 352,

Nanotechnologies, in accordance with the Agreement on technical cooperation between ISO and CEN

(Vienna Agreement).

This second edition cancels and replaces the first edition (ISO/TS 12025:2012), which has been

technically revised.
The main changes compared to the previous edition are as follows:
— revised and updated the Introduction and the Bibliography;

— updated 6.4.1 and 6.4.2 and Annex A with regards to the description and selection of the sample

treatment procedure in accordance with new European standards.

Any feedback or questions on this document should be directed to the user’s national standards body. A

complete listing of these bodies can be found at www .iso .org/ members .html.
iv © ISO 2021 – All rights reserved
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SIST-TS CEN ISO/TS 12025:2021
ISO/TS 12025:2021(E)
Introduction

Industrial powders when subjected to external energy or stress from handling and air flow will release

particles entrained in the surrounding air to form aerosols. Aerosols in the nanoscale are more dynamic

than micrometre sized particles because of greater sensitivity to physical effects such as Brownian

diffusion. Porosity and cohesion of the powder can be much higher than for materials containing

larger particles with more resistance to flow and lower volume-specific surface area. Nano-objects in

powdered nanostructured materials can dominate relevant properties of the bulk material by particle-

particle interactions that form clusters such as agglomerates.

Aerosol release characterization consists of three main stages: generation, transport and measurement.

In general, to reduce transport losses and aerosol agglomeration, the distance between generation and

[35]

measurement should be minimized. Although there are potentially many different approaches ,

the generation of an aerosol is usually physically modelled on different representative scenarios (e.g.

to simulate typical manual or machine powder handling processes or worst-case highly energetic

dispersion).

This document is only applicable for measuring the release of nano-objects from powders. This

allows comparisons of the nano-object release from different powders using the same generation and

measurement system. The choice of the measurement method must take into account the characteristics

(e.g. time-related dependence) of the generation system and the potential for losses and agglomeration

during the transport and entry into the measuring instrumentation. Therefore, this document provides

a summary of the generation and measurement methods currently available to assist material scientists

and engineers in comparing the nano-object release from different powders.

The quantification of the release of nano-objects from powders described in this document cannot be

used as a substitute for dustiness testing or for a health-related risk assessment.

© ISO 2021 – All rights reserved v
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SIST-TS CEN ISO/TS 12025:2021
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SIST-TS CEN ISO/TS 12025:2021
TECHNICAL SPECIFICATION ISO/TS 12025:2021(E)
Nanomaterials — Quantification of nano-object release
from powders by generation of aerosols

WARNING — The execution of the provisions of this document should be entrusted only to

appropriately qualified and experienced people, for whose use it has been produced.

1  Scope

This document describes methods for the quantification of nano-object release from powders as a

result of treatment, ranging from handling to high energy dispersion, by measuring aerosols liberated

after a defined aerosolization procedure. Particle number concentration and size distribution of the

aerosol are measured and the mass concentration is derived. This document provides information

on factors to be considered when selecting among the available methods for powder sampling and

treatment procedures and specifies minimum requirements for test sample preparation, test protocol

development, measuring particle release and reporting data. In order to characterize the full size range

of particles generated, the measurement of nano-objects as well as agglomerates and aggregates is

adressed in this document.

This document does not include the characterization of particle sizes within the powder. Tribological

methods are excluded where direct mechanical friction is applied to grind or abrade the material.

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.

ISO/TS 80004-1:2015, Nanotechnologies — Vocabulary — Part 1: Core terms
ISO/TS 80004-2:2015, Nanotechnologies — Vocabulary — Part 2: Nano-objects
3  Terms and definitions

For the purposes of this document, the terms and definitions given in ISO/TS 80004-1:2015,

ISO/TS 80004-2:2015 and the following apply.

ISO and IEC maintain terminological databases for use in standardization at the following addresses:

— ISO Online browsing platform: available at https:// www .iso .org/ obp
— IEC Electropedia: available at http:// www .electropedia .org/
3.1  General terms
3.1.1
release from powder

transfer of material from a powder to a liquid or gas as a consequence of a disturbance

3.1.2
nano-object number release

total number of nano-objects (3.2.9), released from a sample as a consequence of a disturbance

© ISO 2021 – All rights reserved 1
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SIST-TS CEN ISO/TS 12025:2021
ISO/TS 12025:2021(E)
3.1.3
nano-object release rate

total number of nano-objects (3.2.9), released per second as a consequence of a disturbance

3.1.4
mass specific nano-object number release

nano-object number release (3.1.2), divided by the mass of the sample before a disturbance

3.1.5
mass loss specific nano-object number release

nano-object number release (3.1.2), divided by the mass difference of the sample before and after a

disturbance
3.1.6
nano-object aerosol number concentration

number of nano-objects (3.2.9) per aerosol volume unit in the sample treatment zone

3.1.7
aerosol volume flow rate
volume flow rate through the sample treatment zone
3.2  Terms related to particle properties and measurement
3.2.1
aerosol
system of solid or liquid particles suspended in gas
[SOURCE: ISO 15900:2009, 2.1]
3.2.2
equivalent spherical diameter

diameter of a sphere having the same physical properties as the particle in the measurement

Note 1 to entry: Physical properties are, for instance, the same settling velocity or electrolyte solution displacing

volume or projection area under a microscope.

Note 2 to entry: The physical property to which the equivalent diameter refers shall be indicated using a suitable

subscript, e.g. x for equivalent surface area diameter or x for equivalent volume diameter.

s v
[SOURCE: ISO/TS 80004-2:2015, A.2.3]
3.2.3
particle size distribution
PSD

cumulative distribution or distribution density of a quantity of particle sizes, represented by equivalent

spherical diameters (3.2.2) or other linear dimensions
[3]

Note 1 to entry: Quantity measures and types of distributions are defined in ISO 9276-1:1998 .

3.2.4
2,5
particulate matter smaller than 2,5 µm

mass concentration of fine particulate matter having an aerodynamic diameter less than or equal to a

nominal 2,5 micrometres
Note 1 to entry: See Appendix J in Reference [47].
2 © ISO 2021 – All rights reserved
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SIST-TS CEN ISO/TS 12025:2021
ISO/TS 12025:2021(E)
3.2.5
particulate matter smaller than 10 µm

mass concentration of fine particulate matter having an aerodynamic diameter less than or equal to a

nominal 10 micrometres
Note 1 to entry: See Appendix J in Reference [47].
[15]

Note 2 to entry: PM is used for the thoracic fraction as explained in EN 481:1993 .

3.2.6
condensation particle counter
CPC

instrument that measures the particle number concentration of an aerosol (3.2.1) using a condensation

effect to increase the size of the aerosolized particles

Note 1 to entry: The sizes of particles detected are usually smaller than several hundred nanometres and larger

than a few nanometres.

Note 2 to entry: A CPC is one possible detector for use with a differential electrical mobility classifier (3.2.7).

Note 3 to entry: In some cases, a CPC may be called a “condensation nucleus counter (CNC)”.

[SOURCE: ISO 15900:2020, 3.8, modified — “using a condensation effect to increase the size of the

aerosolized particles” has been added to the definition.]
3.2.7
differential electrical mobility classifier
DEMC

classifier that is able to select aerosol (3.2.1) particles according to their electrical mobility and pass

them to its exit

Note 1 to entry: A DEMC classifies aerosol particles by balancing the electrical force on each particle with its

aerodynamic drag force in an electrical field. Classified particles are in a narrow range of electrical mobility

determined by the operating conditions and physical dimensions of the DEMC, while they can have different sizes

due to difference in the number of charges that they have.
[SOURCE: ISO 15900:2020, 3.11]
3.2.8
differential mobility analysing system
DMAS

system to measure the size distribution of sub-micrometre aerosol (3.2.1) particles consisting of

a differential electrical mobility classifier (3.2.7), flow meters, a particle detector, interconnecting

plumbing, a computer and suitable software
[SOURCE: ISO 15900:2020, 3.12]
3.2.9
nano-object
material with one, two or three external dimensions in the nanoscale (3.2.10)
Note 1 to entry: Generic term for all discrete nanoscaled objects.

[SOURCE: ISO/TS 80004-2:2015, 2.2, modified — “discrete piece of” has been deleted from the start of

the definition and the Note 1 to entry has been replaced.]
3.2.10
nanoscale
size range approximately from 1 nm to 100 nm

Note 1 to entry: Properties that are not extrapolations from a larger size will typically, but not exclusively, be

exhibited in this size range. For such properties, the size limits are considered approximate.

© ISO 2021 – All rights reserved 3
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SIST-TS CEN ISO/TS 12025:2021
ISO/TS 12025:2021(E)

Note 2 to entry: The lower limit in this definition (approximately 1 nm) is introduced to avoid single and small

groups of atoms from being designated as nano-objects (3.2.9) or elements of nanostructures, which could be

implied by the absence of a lower limit.

[SOURCE: ISO/TS 80004-2:2015, 2.1, modified — Note 1 to entry has been replaced and Note 2 to entry

has been added.]
3.2.11
agglomerate

collection of loosely bound particles or aggregates (3.2.12) or mixtures of the two held together by

weak forces where the resulting external surface area is similar to the sum of the surface areas of the

individual components

Note 1 to entry: The weak forces, for example, are van der Waals forces or simple physical entanglement.

Note 2 to entry: Agglomerates are secondary particles and the original source particles are primary particles.

[SOURCE: ISO/TS 80004-2:2015, 3.4, modified — “loosely bound particles or aggregates or mixtures of

the two held together by weak forces” has replaced “weakly or medium strongly bound particles” the

notes to entry have been reworded.]
3.2.12
aggregate

particle comprising strongly bonded or fused particles held together by strong forces where the

resulting external surface area is significantly smaller than the sum of calculated surface areas of the

individual components

Note 1 to entry: The strong forces, for example, are covalent bonds, or those resulting from sintering or complex

physical entanglement.

Note 2 to entry: Aggregates are secondary particles and the original source particles are primary particles.

[SOURCE: ISO/TS 80004-2:2015, 3.5, modified — “held together by strong forces” and “calculated” have

been added to the definition and the notes to entry have been reworded.]
3.2.13
dustiness
propensity of materials to produce airborne dust during handling

Note 1 to entry: For the purpose of this document, dustiness is derived from the amount of dust emitted during a

standard test procedure.

Note 2 to entry: Dustiness is not an intrinsic property as it depends on how it is measured.

[SOURCE: EN 1540:2011, 2.5.1]
3.2.14
inhalable fraction

mass fraction of total airborne particles which is inhaled through the nose and mouth

[15]
Note 1 to entry: The inhalable fraction is specified in EN 481:1993 .
[SOURCE: EN 1540:2011, 2.3.1.1]
3.2.15
thoracic fraction
mass fraction of inhaled particles penetrating beyond the larynx
[15]
Note 1 to entry: The thoracic fraction is specified in EN 481:1993 .
[SOURCE: EN 1540:2011, 2.3.1.2]
4 © ISO 2021 – All rights reserved
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SIST-TS CEN ISO/TS 12025:2021
ISO/TS 12025:2021(E)
3.2.16
respirable fraction
mass fraction of inhaled particles penetrating to the unciliated airways
[15]
Note 1 to entry: The respirable fraction is specified in EN 481:1993 .
[SOURCE: EN 1540:2011, 2.3.1.3]
4  Symbols
For the purposes of this document, the symbols given in Table 1 apply.
Table 1 — Symbols
Symbol Quantity SI unit
n nano-object number release dimensionless
n nano-object release rate s
c nano-object aerosol number concentration m
n mass specific nano-object number release kg
n mass loss specific nano-object number release, from a treated sample with a kg
mass loss ∆m
3 1
V aerosol volume flow rate m /s
5  Factors influencing results of nano-object release from powders
5.1  Test generation method selection

The purpose of the planned test or experimental programme should be carefully defined during the

selection of the aerosol generation method.

Selection of the aerosol generation method depends on the following considerations:

a) the powder properties listed in Table 2;
[17][18][19]

b) the applicability of standardized dustiness test methods, see the EN 15051 series , or of

[32]

other powder treatment methods to simulate the typical powder handling process in practice

[34][37]
as well as selection of the appropriate treatment parameters.

The outcome of the planned test will be dependent on the experimental conditions selected.

EXAMPLE 1 Determination of the nano-object release of a powder to predict release of nanoparticles during

manual and automatic moderate powder handling processes (i.e. weak to moderate dispersion stress) for

industrial processing.

EXAMPLE 2 Estimation of nano-object and agglomerate/aggregate release from powder to simulate worst-

case scenarios of handling process, where a high energy input or high activation energy is applied to the powder

or during the generation of an aerosol for animal inhalation studies. Such high energy input is likely to be used

only in fully contained processes to prevent unacceptable exposures to workers.
5.2  Material properties influencing nano-object release from powder

Properties influencing the generation and measurements of aerosolized powders containing nano-

objects are summarized in Table 2. Presently, it is not necessarily easy to measure many of these

properties; however, they shou
...

SLOVENSKI STANDARD
kSIST-TS FprCEN ISO/TS 12025:2020
01-december-2020
Nanomateriali - Kvantifikacija sproščanja nanoobjektov iz prahu s proizvodnjo
aerosola (ISO/PRF TS 12025:2020)

Nanomaterials - Quantification of nano-object release from powders by generation of

aerosols (ISO/PRF TS 12025:2020)

Nanomaterialien - Quantifizierung der Freisetzung von Nanoobjekten aus Pulvern durch

Aerosolerzeugung (ISO/PRF TS 12025:2020)

Nanomatériaux - Quantification de la libération de nano-objets par les poudres par

production d'aérosols (ISO/PRF TS 12025:2020)
Ta slovenski standard je istoveten z: FprCEN ISO/TS 12025
ICS:
07.120 Nanotehnologije Nanotechnologies
kSIST-TS FprCEN ISO/TS 12025:2020 en,fr,de

2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

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kSIST-TS FprCEN ISO/TS 12025:2020
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kSIST-TS FprCEN ISO/TS 12025:2020
TECHNICAL ISO/TS
SPECIFICATION 12025
Second edition
Nanomaterials — Quantification of
nano-object release from powders by
generation of aerosols
Nanomatériaux — Quantification de la libération de nano-objets par
les poudres par production d'aérosols
Member bodies are requested to consult relevant national interests in IEC/TC
113 before casting their ballot to the e-Balloting application.
PROOF/ÉPREUVE
Reference number
ISO/TS 12025:2020(E)
ISO 2020
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kSIST-TS FprCEN ISO/TS 12025:2020
ISO/TS 12025:2020(E)
COPYRIGHT PROTECTED DOCUMENT
© ISO 2020

All rights reserved. Unless otherwise specified, or required in the context of its implementation, no part of this publication may

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Published in Switzerland
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Contents Page

Foreword ........................................................................................................................................................................................................................................iv

Introduction ..................................................................................................................................................................................................................................v

1  Scope ................................................................................................................................................................................................................................. 1

2  Normative references ...................................................................................................................................................................................... 1

3  Terms and definitions ..................................................................................................................................................................................... 1

3.1 General terms .......................................................................................................................................................................................... 1

3.2 Terms related to particle properties and measurement ..................................................................................... 2

4  Symbols .......................................................................................................................................................................................................................... 5

5  Factors influencing results of nano-object release from powders ...................................................................5

5.1 Test generation method selection .......................................................................................................................................... 5

5.2 Material properties influencing nano-object release from powder .......................................................... 5

5.3 Test stages ................................................................................................................................................................................................... 6

6 Test requirements ............................................................................................................................................................................................... 7

6.1 General ........................................................................................................................................................................................................... 7

6.2 Safety assessment ................................................................................................................................................................................. 7

6.3 Sample preparation ............................................................................................................................................................................ 8

6.4 Sample treatment ................................................................................................................................................................................. 8

6.4.1 Dustiness generation methods ............................................................................................................................ 8

6.4.2 Dispersing methods for aerosol generation ............................................................................................. 9

6.4.3 Sample treatment execution and report ..................................................................................................... 9

6.5 Measurement of aerosolized nano-objects ..................................................................................................................10

6.5.1 Selection of the measuring method ..............................................................................................................10

6.5.2 Transport and sampling parameters ...........................................................................................................11

6.5.3 Considerations before testing ............................................................................................................................12

6.5.4 Size and concentration measurement results .....................................................................................12

6.5.5 Particle size distribution and other characteristic measurement parameters .......14

7  Requirements for test setups and protocols ........................................................................................................................15

8  Data reporting ......................................................................................................................................................................................................16

Annex A (informative) Considerations for the selection of the sample treatment procedure ..............17

Annex B (informative) Dustiness reference test methods ..........................................................................................................19

Annex C (informative) Dynamic method .......................................................................................................................................................21

Annex D (informative) Dispersing methods ..............................................................................................................................................25

Annex E (informative) Selection of the nano-object measuring method .....................................................................26

Annex F (informative) Dry dispersion intensity in measuring devices .........................................................................28

Bibliography .............................................................................................................................................................................................................................29

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ISO/TS 12025:2020(E)
Foreword

ISO (the International Organization for Standardization) is a worldwide federation of national standards

bodies (ISO member bodies). The work of preparing International Standards is normally carried out

through ISO technical committees. Each member body interested in a subject for which a technical

committee has been established has the right to be represented on that committee. International

organizations, governmental and non-governmental, in liaison with ISO, also take part in the work.

ISO collaborates closely with the International Electrotechnical Commission (IEC) on all matters of

electrotechnical standardization.

The procedures used to develop this document and those intended for its further maintenance are

described in the ISO/IEC Directives, Part 1. In particular, the different approval criteria needed for the

different types of ISO documents should be noted. This document was drafted in accordance with the

editorial rules of the ISO/IEC Directives, Part 2 (see www. iso. org/d irectives).

Attention is drawn to the possibility that some of the elements of this document may be the subject of

patent rights. ISO shall not be held responsible for identifying any or all such patent rights. Details of

any patent rights identified during the development of the document will be in the Introduction and/or

on the ISO list of patent declarations received (see www. iso. org/p atents).

Any trade name used in this document is information given for the convenience of users and does not

constitute an endorsement.

For an explanation of the voluntary nature of standards, the meaning of ISO specific terms and

expressions related to conformity assessment, as well as information about ISO’s adherence to the

World Trade Organization (WTO) principles in the Technical Barriers to Trade (TBT), see www. iso. org/

iso/f oreword. html.

This document was prepared jointly by Technical Committee ISO/TC 229, Nanotechnologies, and

Technical Committee IEC/TC 113, Nanotechnology for electrotechnical products and systems, in

collaboration with the European Committee for Standardization (CEN) Technical Committee CEN/TC

352, Nanotechnologies, in accordance with the Agreement on technical cooperation between ISO and

CEN (Vienna Agreement).

This second edition cancels and replaces the first edition (ISO/TS 12025:2012), which has been

technically revised.

Any feedback or questions on this document should be directed to the user’s national standards body. A

complete listing of these bodies can be found at www. iso. org/members . html.
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Introduction

Industrial powders when subjected to external energy or stress from handling and air flow will

release particles entrained in the surrounding air to form aerosols. Aerosols of nano-objects are more

dynamic than micrometre sized particles because of greater sensitivity to physical effects such as

Brownian diffusion. Porosity and cohesion of the powder can be much higher than those containing

larger particles with more resistance to flow and lower volume-specific surface area. Nano-objects in

powdered nanostructured materials can dominate relevant properties of the bulk material by particle-

particle interactions that form clusters such as agglomerates.

Aerosol release characterization consists of three main stages: generation, transport and measurement.

In general, to reduce transport losses and aerosol agglomeration, the distance between generation and

[35]

measurement should be minimized. Although there are potentially many different approaches ,

the generation of an aerosol is usually physically modelled on different representative scenarios (e.g.

to simulate typical manual or machine powder handling processes or worst case highly energetic

dispersion).

This document is only applicable for measuring the release of nano-objects from powders. This

allows comparisons of the nano-object release from different powders using the same generation and

measurement system. The choice of the measurement method must take into account the characteristics

(e.g. time-related dependence) of the generation system and the potential for losses and agglomeration

during the transport and entry into the measuring instrumentation. Therefore, this document provides

a summary of the generation and measurement methods currently available to assist material scientists

and engineers in comparing the nano-object release from different powders.

The quantification of the release of nano-objects from powders described in this document cannot be

used as a substitute for dustiness testing or for a health-related risk assessment.

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kSIST-TS FprCEN ISO/TS 12025:2020
TECHNICAL SPECIFICATION ISO/TS 12025:2020(E)
Nanomaterials — Quantification of nano-object release
from powders by generation of aerosols

WARNING — The execution of the provisions of this document should be entrusted only to

appropriately qualified and experienced people, for whose use it has been produced.

1  Scope

This document describes methods for the quantification of nano-object release from powders as a

result of treatment, ranging from handling to high energy dispersion, by measuring aerosols liberated

after a defined aerosolization procedure. Particle number concentration and size distribution of the

aerosol are measured and the mass concentration is derived. This document provides information

on factors to be considered when selecting among the available methods for powder sampling and

treatment procedures and specifies minimum requirements for test sample preparation, test protocol

development, measuring particle release and reporting data. In order to characterize the full size range

of particles generated, the measurement of nano-objects as well as agglomerates and aggregates is

recommended in this document.

This document does not include the characterization of particle sizes within the powder. Tribological

methods are excluded where direct mechanical friction is applied to grind or abrade the material.

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.

ISO/TS 80004-1:2015, Nanotechnologies — Vocabulary — Part 1: Core terms
ISO/TS 80004-2:2015, Nanotechnologies — Vocabulary — Part 2: Nano-objects
3  Terms and definitions

For the purposes of this document, the terms and definitions given in ISO/TS 80004-1:2015,

ISO/TS 80004-2:2015 and the following apply.

ISO and IEC maintain terminological databases for use in standardization at the following addresses:

— ISO Online browsing platform: available at https:// www .iso .org/ obp
— IEC Electropedia: available at http:// www .electropedia .org/
3.1  General terms
3.1.1
release from powder

transfer of material from a powder to a liquid or gas as a consequence of a disturbance

3.1.2
nano-object number release

total number of nano-objects (3.2.9), released from a sample as a consequence of a disturbance

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3.1.3
nano-object release rate

total number of nano-objects (3.2.9), released per second as a consequence of a disturbance

3.1.4
mass specific nano-object number release

nano-object number release (3.1.2), divided by the mass of the sample before a disturbance

3.1.5
mass loss specific nano-object number release

nano-object number release (3.1.2), divided by the mass difference of the sample before and after a

disturbance
3.1.6
nano-object aerosol number concentration

number of nano-objects (3.2.9) per aerosol volume unit in the sample treatment zone

3.1.7
aerosol volume flow rate
volume flow rate through the sample treatment zone
3.2  Terms related to particle properties and measurement
3.2.1
aerosol
system of solid or liquid particles suspended in gas
[SOURCE: ISO 15900:2009, 2.1]
3.2.2
equivalent spherical diameter

diameter of a sphere having the same physical properties as the particle in the measurement

Note 1 to entry: Physical properties are, for instance, the same settling velocity or electrolyte solution displacing

volume or projection area under a microscope.

Note 2 to entry: The physical property to which the equivalent diameter refers shall be indicated using a suitable

subscript, e.g. x for equivalent surface area diameter or x for equivalent volume diameter.

s v
[SOURCE: ISO/TS 80004-2:2015, A.2.3]
3.2.3
particle size distribution
PSD

cumulative distribution or distribution density of a quantity of particle sizes, represented by equivalent

spherical diameters (3.2.2) or other linear dimensions
[3]

Note 1 to entry: Quantity measures and types of distributions are defined in ISO 9276-1:1998 .

3.2.4
PM2,5
particulate matter smaller than 2,5 µm

mass concentration of fine particulate matter having an aerodynamic diameter less than or equal to a

nominal 2,5 micrometres (PM , )
2 5
Note 1 to entry: See Appendix J in Reference [47].
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3.2.5
PM10
particulate matter smaller than 10 µm

mass concentration of fine particulate matter having an aerodynamic diameter less than or equal to a

nominal 10 micrometres (PM )
Note 1 to entry: See Appendix J in Reference [47].
[15]

Note 2 to entry: PM10 is used for the thoracic fraction as explained in EN 481:1993 .

3.2.6
condensation particle counter
CPC

instrument that measures the particle number concentration of an aerosol (3.2.1) using a condensation

effect to increase the size of the aerosolized particles

Note 1 to entry: The sizes of particles detected are usually smaller than several hundred nanometres and larger

than a few nanometres.

Note 2 to entry: A CPC is one possible detector for use with a differential electrical mobility classifier (3.2.7).

Note 3 to entry: In some cases, a CPC may be called a “condensation nucleus counter (CNC)”.

[SOURCE: ISO 15900:2009, 2.5, modified — “using a condensation effect to increase the size of the

aerosolized particles” as been added to the definition.]
3.2.7
differential electrical mobility classifier
DEMC

classifier that is able to select aerosol (3.2.1) particles according to their electrical mobility and pass

them to its exit

Note 1 to entry: A DEMC classifies aerosol particles by balancing the electrical force on each particle with its

aerodynamic drag force in an electrical field. Classified particles are in a narrow range of electrical mobility

determined by the operating conditions and physical dimensions of the DEMC, while they can have different sizes

due to difference in the number of charges that they have.
[SOURCE: ISO 15900:2009, 2.7]
3.2.8
differential mobility analysing system
DMAS

system to measure the size distribution of sub-micrometre aerosol (3.2.1) particles consisting of

a differential electrical mobility classifier (3.2.7), flow meters, a particle detector, interconnecting

plumbing, a computer and suitable software
[SOURCE: ISO 15900:2009, 2.8]
3.2.9
nano-object
material with one, two or three external dimensions in the nanoscale (3.2.10)
Note 1 to entry: Generic term for all discrete nanoscaled objects.

[SOURCE: ISO/TS 80004-2:2015, 2.2, modified — “discrete piece of” has been deleted from the start of

the definition and the Note 1 to entry has been replaced.]
3.2.10
nanoscale
size range approximately from 1 nm to 100 nm

Note 1 to entry: Properties that are not extrapolations from a larger size will typically, but not exclusively, be

exhibited in this size range. For such properties, the size limits are considered approximate.

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Note 2 to entry: The lower limit in this definition (approximately 1 nm) is introduced to avoid single and small

groups of atoms from being designated as nano-objects (3.2.9) or elements of nanostructures, which could be

implied by the absence of a lower limit.

[SOURCE: ISO/TS 80004-2:2015, 2.1, modified — Note 1 to entry has been replaced and Note 2 to entry

has been added.]
3.2.11
agglomerate

collection of loosely bound particles or aggregates (3.2.12) or mixtures of the two held together by

weak forces where the resulting external surface area is similar to the sum of the surface areas of the

individual components

Note 1 to entry: The weak forces, for example, are van der Waals forces or simple physical entanglement.

Note 2 to entry: Agglomerates are secondary particles and the original source particles are primary particles.

[SOURCE: ISO/TS 80004-2:2015, 3.4, modified — “loosely bound particles or aggregates or mixtures

of the two” has replaced “weakly or medium strongly bound particles” the notes to entry have been

reworded.]
3.2.12
aggregate

particle comprising strongly bonded or fused particles held together by strong forces where the

resulting external surface area is significantly smaller than the sum of calculated surface areas of the

individual components

Note 1 to entry: The strong forces, for example, are covalent bonds, or those resulting from sintering or complex

physical entanglement.

Note 2 to entry: Aggregates are secondary particles and the original source particles are primary particles.

[SOURCE: ISO/TS 80004-2:2015, 3.5, modified — “held together by strong forces” has been added to the

definition and the notes to entry have been reworded.]
3.2.13
dustiness
propensity of materials to produce airborne dust during handling

Note 1 to entry: For the purpose of this document, dustiness is derived from the amount of dust emitted during a

standard test procedure.

Note 2 to entry: Dustiness is not an intrinsic property as it depends on how it is measured.

[SOURCE: EN 1540:2011, 2.5.1]
3.2.14
inhalable fraction

mass fraction of total airborne particles which is inhaled through the nose and mouth

[15]
Note 1 to entry: The inhalable fraction is specified in EN 481:1993 .
[SOURCE: EN 1540:2011, 2.3.1.1]
3.2.15
thoracic fraction
mass fraction of inhaled particles penetrating beyond the larynx
[15]
Note 1 to entry: The thoracic fraction is specified in EN 481:1993 .
[SOURCE: EN 1540:2011, 2.3.1.2]
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3.2.16
respirable fraction
mass fraction of inhaled particles penetrating to the unciliated airways
[15]
Note 1 to entry: The respirable fraction is specified in EN 481:1993 .
[SOURCE: EN 1540:2011, 2.3.1.3]
4  Symbols
For the purposes of this document, the following symbols apply.
Symbol Quantity SI unit
n nano-object number release dimensionless
n nano-object release rate s
c nano-object aerosol number concentration m
n mass specific nano-object number release kg
n mass loss specific nano-object number release, from a treated sample with a kg
mass loss ∆m
3 −1
V aerosol volume flow rate m s
5  Factors influencing results of nano-object release from powders
5.1  Test generation method selection

The purpose of the planned test or experimental programme should be carefully defined during the

selection of the aerosol generation method.

Selection of the aerosol generation method depends on the following considerations:

a) the powder properties listed in Table 1;
[17][18][19]

b) the applicability of standardized dustiness test methods, see the EN 15051 series , or of

[32]

other powder treatment methods to simulate the typical powder handling process in practice

[34][37]
as well as selection of the appropriate treatment parameters.

The outcome of the planned test will be dependent on the experimental conditions selected.

EXAMPLE 1 Determination of the nano-object release of a powder to predict release of nanoparticles during

manual and automatic moderate powder handling processes (i.e. weak to moderate dispersion stress) for

industrial processing.

EXAMPLE 2 Estimation of nano-object and agglomerate/aggregate release from powder to simulate worst

case scenarios of handling process, where a high energy input or high activation energy is applied to the powder

or during the generation of an aerosol for animal inhalation studies. Such high energy input is likely to be used

only in fully contained processes to prevent unacceptable exposures to workers.
5.2  Material properties influencing nano-object release from powder

Properties influencing the generation and measurements of aerosolized powders containing nano-

objects are summarized in Table 1. Presently, it is not necessarily easy to measure many of these

properties; however, they should be considered.

These material-specific properties of powder are relevant to test design (see Clause 6) and data

reporting (see Clause 8).
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Table 1 — Representative properties influencing nano-object release from powders
Property Description

Particle size The value of the particle size depends on the sizing method and the corresponding

equivalent diameter (e.g. aerodynamic diameter, electrical mobility diameter, equiva-

lent area diameter).

The particle size of primary particles or aggregates will not change during the han-

dling of nanostructured powders. Particle size of agglomerates will change under

certain process and handling conditions. Therefore, it can behave like a process pa-

rameter.

The measured size distribution of particles will depend on the type of instrument. The

instrument can measure aerodynamic or mobility diameters, specific surface areas

or other parameters. The exact shape of primary particles will depend on the man-

ufacturing process. Nano-objects can be a small fraction of the total mass for some

materials.

Particle shape Particle shapes are found in a wide range of geometries depending on the material and

the process. Agglomerates and aggregates of nano-objects can have a fractal shape.

Adhesion forces depend on the particle shape because of the contact geometry.

Crystallinity Some powdered materials can exist in various crystalline states or in amorphous

form. The fraction of the crystalline phase can vary depending on the particle size.

Hygroscopicity and Interaction of the particle with moisture in the air characterized by the relative hu-

moisture content midity will affect the cohesion of the particles. Thus, the history of the relative humidi-

ty of the environmental conditions used to store the powder can be important.

The hydrophobic versus hydrophilic characteristics affect dustiness because as time

goes on a hydrophilic nanomaterial such as magnesium oxide will become less dusty

as it absorbs water from the air. Some synthetic amorphous silica, on the other hand,

can be easily electrostatically charged and is readily aerosolized.

Cohesion The magnitude of adhesion forces between particles will affect the detachment of par-

ticles as force is introduced into the system. Cohesion will affect the porosity between

the particles and flow ability of the powder. The tendency of the nanopowders to sinter

or agglomerate is also a consideration.

Material density The material density will affect aerosolization. For example, some tungsten oxide has

a high density and is not very dusty.

Porosity Porosity is a measure of the void spaces in a material. This includes the porosity of pri-

mary nano-objects, agglomerates and generally the packing density of the bulk powder.

Electrical resistivity The electrical resistance of the powder affects the ability of the system to dissipate

electrical charge.

Triboelectrics The ability of the material to generate static electricity will affect the forces within

the powder.
5.3  Test stages

A schematic overview of the test stages necessary for the quantification of nano-object release from

powders is shown in Figure 1. Based on the multitude of factors that influence sample preparation and

sample treatment and the current lack of understanding of sample treatment, this document provides

requirements on the basic conditions for the aerosol measurement stage.
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Figure 1 — S
...

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