SIST EN 17199-5:2019
(Main)Workplace exposure - Measurement of dustiness of bulk materials that contain or release respirable NOAA or other respirable particles - Part 5: Vortex shaker method
Workplace exposure - Measurement of dustiness of bulk materials that contain or release respirable NOAA or other respirable particles - Part 5: Vortex shaker method
This document describes the methodology for measuring and characterizing the dustiness of bulk materials that contain or release respirable NOAA or other respirable particles, under standard and reproducible conditions and specifies for that purpose the vortex shaker method.
This document specifies the selection of instruments and devices and the procedures for calculating and presenting the results. It also gives guidelines on the evaluation and reporting of the data.
The methodology described in this document enables
a) the measurement of the respirable dustiness mass fraction,
b) the measurement of the number-based dustiness index of respirable particles in the particle size range from about 10 nm to about 1 µm,
c) the measurement of the number-based emission rate of respirable particles in the particle size range from about 10 nm to about 1 µm,
d) the measurement of the number-based particle size distribution of the released respirable aerosol in the particle size range from about 10 nm to 10 µm,
e) the collection of released airborne particles in the respirable fraction for subsequent observations and analysis by electron microscopy.
This document is applicable to the testing of a wide range of bulk materials including nanomaterials in powder form.
NOTE 1 With slightly different configurations of the method specified in this document, dustiness of a series of carbon nanotubes has been investigated ([5] to [10]). On the basis of this published work, it can be assumed that the vortex shaker method is also applicable to nanofibres and nanoplates.
This document is not applicable to millimetre-sized granules or pellets containing nano-objects in either unbound, bound uncoated and coated forms.
NOTE 2 The restrictions with regard to the application of the vortex shaker method on different kinds of nanomaterials result from the configuration of the vortex shaker apparatus as well as from the small size of the test sample required. Eventually, if future work will be able to provide accurate and repeatable data demonstrating that an extension of the method applicability is possible, the intention is to revise this document and to introduce further cases of method application.
NOTE 3 As observed in the pre-normative research project [4], the vortex shaker method specified in this document provides a more energetic aerosolization than the rotating drum, the continuous drop and the small rotating drum methods specified in FprEN 17199 2 [1], FprEN 17199 3 [2] and FprEN 17199 4 [3], respectively. The vortex shaker method can better simulate high energy dust dispersion operations or processes where vibration or shaking is applied or even describe a worst case scenario in a workplace, including the (non-recommended) practice of cleaning contaminated worker coveralls and dry work surfaces with compressed air.
NOTE 4 Currently no classification scheme in terms of dustiness indices or emission rates has been established according to the vortex shaker method. Eventually, when a large number of measurement data has been obtained, the intention is to revise the document and to introduce such a classification scheme, if applicable.
Exposition am Arbeitsplatz - Messung des Staubungsverhaltens von Schüttgütern, die Nanoobjekte oder Submikrometerpartikel enthalten oder freisetzen - Teil 5: Verfahren mit Vortex-Schüttler
Diese Europäische Norm enthält die Methodik für die Messung und Charakterisierung des Staubungs-verhaltens von Schüttgütern, die Nanoobjekte oder Partikel im Submikrometerbereich enthalten oder unter wiederholbaren und Standardbedingungen freisetzen, und legt zu diesem Zweck das Verfahren mit Vortex-Schüttler fest.
Darüber hinaus legt diese Europäische Norm die Auswahl der Instrumente und Vorrichtungen sowie die Verfahren für die Berechnung und Präsentation der Ergebnisse fest. Des Weiteren enthält die Norm eine Anleitung für die Auswertung und Angabe der Daten.
Die in dieser Europäischen Norm festgelegte Methodik ermöglicht
a) die Berechnung des Massenanteils an alveolengängigem Staub;
b) die Bestimmung des massenbasierten Staubindex alveolengängiger Partikel im Größenbereich zwischen ungefähr 10 nm und 1 000 nm;
c) die Bestimmung des zahlenbasierten Staubindex alveolengängiger Partikel im Größenbereich zwischen ungefähr 10 nm und 1 000 nm;
d) die Bestimmung der zahlenbasierten Emissionsrate alveolengängiger Partikel im Größenbereich zwischen ungefähr 10 nm und 1 000 nm;
e) die Bestimmung der zahlenbasierten Größenverteilung des freigesetzten einatembaren Aerosols im Größenbereich zwischen ungefähr 10 nm und 10 µm;
f) die Sammlung freigesetzter Schwebstoffe in der alveolengängigen Fraktion für anschließende Beobachtungen und Analysen durch Elektronenmikroskopie.
Diese Europäische Norm ist für die Prüfung einer Vielzahl verschiedener Schüttgüter einschließlich Nanomaterialien in Pulverform anwendbar.
ANMERKUNG 1 Das Staubungsverhalten einer Reihe Carbon-Nanoröhrchen wurde mit einer von dem in dieser Europäischen Norm festgelegten Verfahren leicht abweichenden Konfiguration untersucht ([5] bis [10]). Auf der Grundlage dieser veröffentlichten Arbeiten kann angenommen werden, dass das Verfahren mit Vortex-Schüttler auch für Nanofasern und Nanoplättchen anwendbar ist.
Diese Europäische Norm ist nicht für Granulate und Pellets im Millimeter-Größenbereich anwendbar, die Nanoobjekte in ungebundener, gebundener, unbeschichteter oder beschichteter Form enthalten.
ANMERKUNG 2 Dies liegt an der Konfiguration des Vortex-Schüttlers und der geringen erforderlichen Prüfprobe. Sofern zukünftige Arbeiten korrekte und wiederholbare Daten liefern, die nachweisen, dass dies möglich ist, ist beabsichtigt, die Europäische Norm zu revidieren und diese Anwendung einzuführen.
ANMERKUNG 3 Das vornormative Forschungsprojekt [4] hat gezeigt, dass das in dieser Europäischen Norm festgelegte Verfahren mit Vortex-Schüttler eine energetischere Zerstäubung ermöglicht als das Verfahren mit rotierender Trommel, kontinuierlichem Fall und kleiner rotierender Trommel respektive nach prEN 17199 2:2017 [1], prEN 17199 3:2017 [2] und prEN 17199 4:2017 [3]. Das Verfahren kann Arbeiten oder Prozesse mit hochenergetischer Staubdispersion durch Vibration besser simulieren oder sogar ein Worst-Case-Szenario am Arbeitsplatz einschließlich der (nicht empfohlenen) Praxis der Reinigung kontaminierter Arbeitsoveralls und trockener Arbeitsoberflächen mit Druckluft beschreiben.
ANMERKUNG 4 Bisher wurde noch kein Klassifizierungsschema im Hinblick auf Staubungsindizes oder Emissions-raten nach dem Verfahren mit Vortex-Schüttler erstellt. Schließlich, wenn eine große Anzahl an Messdaten vorliegt, ist beabsichtigt, diese Europäische Norm zu revidieren und ein solches Klassifizierungsschema einzuführen.
Exposition sur les lieux de travail - Mesurage du pouvoir de resuspension des matériaux en vrac contenant ou émettant des nano-objets et leurs agrégats et agglomérats (NOAA) ou autres particules en fraction alvéolaire - Partie 5: Méthode impliquant l'utilisation d'un agitateur vortex
Le présent document décrit la méthodologie permettant de mesurer et de caractériser le pouvoir de resuspension de matériaux en vrac contenant ou émettant des NOAA ou autres particules en fraction alvéolaire dans des conditions normalisées et reproductibles et spécifie, à cette fin, le but de la méthode de l’agitateur vortex.
Le présent document spécifie le choix des instruments et dispositifs ainsi que les procédures de calcul et d’expression des résultats. Il fournit également des lignes directrices concernant l’évaluation et la consignation des données.
La méthodologie décrite dans le présent document permet :
a) le mesurage de la fraction massique des poussières alvéolaires ;
b) le mesurage de l’indice du pouvoir de resuspension en nombre de particules alvéolaires dans la plage granulométrique comprise entre environ 10 nm et 1 µm ;
Izpostavljenost na delovnem mestu - Meritve prašnosti razsutih materialov, ki vsebujejo ali sproščajo respirabilne nanopredmete ter njihove agregate in aglomerate (NOAA) in druge respirabilne delce - 5. del: Metoda s krožnim mešalnikom
Ta evropski standard določa metodologijo za merjenje in opredelitev prašnosti razsutih materialov, ki vsebujejo ali sproščajo nanopredmete ali submikrometrske delce v standardnih in ponovljivih pogojih, ter za ta namen določa metodo s krožnim mešalnikom.
Poleg tega navaja ta evropski standard tudi izbiro instrumentov in naprav ter postopke za izračun in predstavitev rezultatov. Podaja tudi smernice za vrednotenje in poročanje podatkov.
Metodologija, ki je opisana v tem evropskem standardu, omogoča:
a) merjenje masnega deleža pri respirabilni prašnosti,
b) določanje indeksa prašnosti na podlagi mase respirabilnih delcev v razponu velikosti od približno 10 nm to 1000 nm;
c) določanje indeksa prašnosti respirabilnih delcev na podlagi števila v razponu velikosti od približno 10 nm to 1000 nm;
d) določanje stopnje emisij respirabilnih delcev na podlagi števila v razponu velikosti od približno 10 nm to 1000 nm;
e) določanje števila porazdelitev velikosti sproščenega respirabilnega aerosola v razponu velikosti od približno 10 nm to 10 µm;
f) zbiranje sproščenih lebdečih delcev v respirabilnih deležih za nadaljnje opazovanje in analizo z elektronsko mikroskopijo.
Ta evropski standard se uporablja za preskušanje širokega nabora razsutih materialov, vključno z nanomateriali v prahu.
OPOMBA 1: Prašnost niza ogljikovih nanocevk je bila preiskana (od [5] do [10]) z nekoliko drugačnimi konfiguracijami metode, ki je navedena v tem evropskem standardu. Na podlagi tega objavljenega dela je mogoče sklepati, da se lahko metoda s krožnim mešalnikom uporablja tudi za nanovlakna in nanoplošče.
Ta evropski standard se ne uporablja za milimetrske granule ali pelete, ki vsebujejo nanopredmete v nevezani, vezani, prevlečeni ali neprevlečeni obliki.
OPOMBA 2: To izhaja iz konfiguracije naprave s krožnim mešalnikom in potreben je majhen preskusni vzorec. Če bo delo v prihodnje prineslo točne in ponovljive podatke, ki bi pokazali, da je to mogoče, bo predvidena revizija evropskega standarda in uvedba te uporabe.
OPOMBA 3: Kot je bilo ugotovljeno v prednormativnem raziskovalnem projektu [4], omogoča metoda s krožnim mešalnikom, ki je navedena v tem evropskem standardu, bolj energetsko aerosolizacijo v primerjavi z vrtečim bobnom, trajnim padanjem in majhnim vrtečim bobnom, ki so navedeni v standardih prEN 17199-2:2018 [1], prEN 17199-3:2018 [2] oziroma prEN 17199-4:2018 [3]. Omogoča boljšo simulacijo visokoenergijskih postopkov in procesov razprševanja prahu, pri katerih se uporablja vibracija, ali celo opis najslabšega možnega scenarija na delovnem mestu, vključno s prakso čiščenja kontaminiranih delavskih kombinezonov in suhih delovnih površin s stisnjenim zrakom (se ne priporoča).
OPOMBA 4: Za indekse prašnosti ali stopnje emisij trenutno še ni vzpostavljena nobena klasifikacijska shema v skladu z metodo s krožnim mešalnikom. Ko bo sčasoma pridobljenih veliko merilnih podatkov, je predvidena revizija evropskega standarda in uvedba take klasifikacijske sheme, če bo to ustrezno.
General Information
Relations
Standards Content (Sample)
SLOVENSKI STANDARD
01-september-2019
Izpostavljenost na delovnem mestu - Meritve prašnosti razsutih materialov, ki
vsebujejo ali sproščajo respirabilne nanopredmete ter njihove agregate in
aglomerate (NOAA) in druge respirabilne delce - 5. del: Metoda s krožnim
mešalnikom
Workplace exposure - Measurement of dustiness of bulk materials that contain or
release respirable NOAA or other respirable particles - Part 5: Vortex shaker method
Exposition am Arbeitsplatz - Messung des Staubungsverhaltens von Schüttgütern, die
Nanoobjekte oder Submikrometerpartikel enthalten oder freisetzen - Teil 5: Verfahren
mit Vortex-Schüttler
Exposition sur les lieux de travail - Mesurage du pouvoir de resuspension des matériaux
en vrac contenant ou émettant des nano-objets et leurs agrégats et agglomérats (NOAA)
ou autres particules en fraction alvéolaire - Partie 5: Méthode impliquant l'utilisation d'un
agitateur vortex
Ta slovenski standard je istoveten z: EN 17199-5:2019
ICS:
13.040.30 Kakovost zraka na delovnem Workplace atmospheres
mestu
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.
EN 17199-5
EUROPEAN STANDARD
NORME EUROPÉENNE
March 2019
EUROPÄISCHE NORM
ICS 13.040.30
English Version
Workplace exposure - Measurement of dustiness of bulk
materials that contain or release respirable NOAA or other
respirable particles - Part 5: Vortex shaker method
Exposition sur les lieux de travail - Mesurage du Exposition am Arbeitsplatz - Messung des
pouvoir de resuspension des matériaux en vrac Staubungsverhaltens von Schüttgütern, die
contenant ou émettant des nano-objets et leurs Nanoobjekte oder Submikrometerpartikel enthalten
agrégats et agglomérats (NOAA) ou autres particules oder freisetzen - Teil 5: Verfahren mit Vortex-Schüttler
en fraction alvéolaire - Partie 5: Méthode impliquant
l'utilisation d'un agitateur vortex
This European Standard was approved by CEN on 8 February 2019.
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. Up-to-date lists and bibliographical references
concerning such national standards may be obtained on application to the CEN-CENELEC Management Centre or to any CEN
member.
This European Standard exists 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, Former Yugoslav Republic of Macedonia, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania,
Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, 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
© 2019 CEN All rights of exploitation in any form and by any means reserved Ref. No. EN 17199-5:2019 E
worldwide for CEN national Members.
Contents Page
European foreword . 4
Introduction . 5
1 Scope . 6
2 Normative references . 7
3 Terms and definitions . 7
4 Symbols and abbreviations . 8
5 Principle . 8
6 Equipment . 10
6.1 General . 10
6.2 Test apparatus. 12
6.2.1 Vortex shaker apparatus . 12
6.2.2 Cylindrical container . 12
6.2.3 Humidification system of incoming and dilution air. 15
6.2.4 Sampling line for the measurement of the respirable dustiness mass fraction . 15
6.2.5 Sampling line for other measurements . 17
6.2.6 Conductive flexible tubing, carbon impregnated . 19
6.2.7 Respirable cyclone, made of stainless steel . 19
6.2.8 Air sampling cassette . 19
6.2.9 Condensation particle counter (CPC), with alcohol as working fluid. 20
6.2.10 Time- and size-resolving aerosol instrument . 20
6.2.11 Aerosol sampler for analytical electron microscopy analysis . 20
6.2.12 Analytical balance, capable of weighing to a resolution of 10 µg . 21
6.2.13 Microbalance, capable of weighing to a resolution of 1 µg . 21
6.2.14 Filters for gravimetric analysis . 21
6.2.15 Micro-centrifuge tubes . 21
7 Requirements . 21
7.1 General . 21
7.2 Engineering control measures . 21
7.3 Conditioning of the test material . 21
7.3.1 General . 21
7.3.2 Specified conditions . 22
7.3.3 As-received conditions . 22
7.4 Conditioning of the test equipment . 22
8 Preparation . 22
8.1 Test sample . 22
8.2 Moisture content of the test material . 23
8.3 Bulk density of the test material . 23
8.4 Preparation of test apparatus . 23
8.5 Aerosol instruments and aerosol samplers. 23
9 Test procedure . 23
10 Evaluation of data . 26
10.1 Respirable dustiness mass fraction . 26
10.2 Number-based dustiness index, number-based emission rate and modal
aerodynamic equivalent diameters of the particle size distribution . 26
10.2.1 General . 26
10.2.2 Number-based dustiness index . 27
10.2.3 Number-based emission rate . 27
10.2.4 Modal aerodynamic equivalent diameters of the number-based particle size
distribution . 27
10.3 Morphological and chemical characterization of the particles. 28
11 Test report . 29
Annex A (informative) Pictures illustrating some of the equipment of the method . 30
Annex B (informative) Examples of TEM images obtained with the vortex shaker method . 35
Annex C (informative) Motivation for development of the vortex shaker method . 36
Bibliography . 37
European foreword
This document (EN 17199-5:2019) has been prepared by Technical Committee CEN/TC 137
“Assessment of workplace exposure to chemical and biological agents”, the secretariat of which is held
by DIN.
This European Standard shall be given the status of a national standard, either by publication of an
identical text or by endorsement, at the latest by September 2019 and conflicting national standards
shall be withdrawn at the latest by September 2019.
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 has been prepared under a mandate given to CEN by the European Commission and the
European Free Trade Association.
According to the CEN-CENELEC Internal Regulations, the national standards organizations of the
following countries are bound to implement this European Standard: Austria, Belgium, Bulgaria,
Croatia, Cyprus, Czech Republic, Denmark, Estonia, Finland, Former Yugoslav Republic of Macedonia,
France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta,
Netherlands, Norway, Poland, Portugal, Romania, Serbia, Slovakia, Slovenia, Spain, Sweden, Switzerland,
Turkey and the United Kingdom.
Introduction
Dustiness measurement and characterization provide users (e.g. manufacturers, producers,
occupational hygienists and workers) with information on the potential for dust emissions when bulk
material is handled or processed in workplaces. They provide the manufactures of bulk materials
containing NOAA with information that can help to improve their products and reduce their dustiness.
It allows the users of the bulk materials containing NOAA to assess the controls and precautions
required for handling and working with the material and the effects of pre-treatments (e.g. modify
surface properties or chemistry). It also allows the users to select less dusty products, if available. The
particle size distribution of the aerosol and the morphology and chemical composition of its particles
can be used by occupational hygienists, scientists and regulators to further characterize the aerosol in
terms of particle size distribution and chemical composition and to thus aid users to evaluate and
control the health risk of airborne dust.
This document gives details on the design and operation of the vortex shaker test method that
measures the dustiness of bulk materials that contain or release respirable NOAA or other respirable
particles in terms of dustiness indices or emission rates. Dustiness indices as well as emission rates can
be determined number- or mass-based. In addition the test method characterizes the released aerosol
by measuring the particle size distribution using direct-reading aerosol instruments and collects
samples for off-line analysis (as required) for their morphology and their chemical composition.
The vortex shaker method is useful for addressing the ability of bulk materials including nanomaterials
(in powder form), to release airborne particles (aerosol) during agitation, the so-called dustiness.
The vortex shaker method provides a simulation of operation or processes where the agitation
mechanism delivering energy to the powder to release airborne particles is the vibration or shaking
mechanism. Vibration and shaking are mechanisms that are often found in industry, either voluntarily
or involuntarily. Many surfaces receiving powders are vibrating or shaking, as for example during
powder transportation by belt feeder or vibrating conveyor. Moreover, by providing an energetic
aerosolization, the vortex shaker method provides even a simulation of the worst-case scenario in a
workplace, as for example the (non-recommended) practice of cleaning contaminated worker coveralls
and dry work surfaces with compressed air.
The vortex shaker method presented here differs from the rotating drum, the continuous drop and the
small rotating drum methods presented in EN 17199-2 [1], EN 17199-3 [2] and EN 17199-4 [3]
respectively. The rotating drum and small rotating drum methods perform, both, repeated agitation of
the same sample nanomaterial while the continuous drop method simulates continuous feed of a
nanomaterial. The method described in this document, in turn, provides an agitation to a small test
sample of powder.
This document was developed based on the results of pre-normative research [4]. This project
investigated the dustiness of ten bulk materials (including nine bulk nanomaterials) with the intention
to test as wide a range of bulk materials as possible in terms of magnitude of dustiness, chemical
composition and primary particle size distribution as indicated by a large range in specific surface area.
1 Scope
This document describes the methodology for measuring and characterizing the dustiness of bulk
materials that contain or release respirable NOAA or other respirable particles, under standard and
reproducible conditions and specifies for that purpose the vortex shaker method.
This document specifies the selection of instruments and devices and the procedures for calculating and
presenting the results. It also gives guidelines on the evaluation and reporting of the data.
The methodology described in this document enables
a) the measurement of the respirable dustiness mass fraction,
b) the measurement of the number-based dustiness index of respirable particles in the particle size
range from about 10 nm to about 1 µm,
c) the measurement of the number-based emission rate of respirable particles in the particle size
range from about 10 nm to about 1 µm,
d) the measurement of the number-based particle size distribution of the released respirable aerosol
in the particle size range from about 10 nm to 10 µm,
e) the collection of released airborne particles in the respirable fraction for subsequent observations
and analysis by electron microscopy.
This document is applicable to the testing of a wide range of bulk materials including nanomaterials in
powder form.
NOTE 1 With slightly different configurations of the method specified in this document, dustiness of a series of
carbon nanotubes has been investigated ([5] to [10]). On the basis of this published work, it can be assumed that
the vortex shaker method is also applicable to nanofibres and nanoplates.
This document is not applicable to millimetre-sized granules or pellets containing nano-objects in
either unbound, bound uncoated and coated forms.
NOTE 2 The restrictions with regard to the application of the vortex shaker method on different kinds of
nanomaterials result from the configuration of the vortex shaker apparatus as well as from the small size of the
test sample required. Eventually, if future work will be able to provide accurate and repeatable data
demonstrating that an extension of the method applicability is possible, the intention is to revise this document
and to introduce further cases of method application.
NOTE 3 As observed in the pre-normative research project [4], the vortex shaker method specified in this
document provides a more energetic aerosolization than the rotating drum, the continuous drop and the small
rotating drum methods specified in EN 17199-2 [1], EN 17199-3 [2] and EN 17199-4 [3], respectively. The vortex
shaker method can better simulate high energy dust dispersion operations or processes where vibration or
shaking is applied or even describe a worst case scenario in a workplace, including the (non-recommended)
practice of cleaning contaminated worker coveralls and dry work surfaces with compressed air.
NOTE 4 Currently no classification scheme in terms of dustiness indices or emission rates has been established
according to the vortex shaker method. Eventually, when a large number of measurement data has been obtained,
the intention is to revise the document and to introduce such a classification scheme, if applicable.
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.
CEN ISO/TS 80004-2, Nanotechnologies - Vocabulary - Part 2: Nano-objects (ISO/TS 80004-2)
EN 481, Workplace atmospheres - Size fraction definitions for measurement of airborne particles
EN 1540, Workplace exposure - Terminology
EN 13205-2, Workplace exposure - Assessment of sampler performance for measurement of airborne
particle concentrations - Part 2: Laboratory performance test based on determination of sampling
efficiency
EN 15051-1, Workplace exposure - Measurement of the dustiness of bulk materials - Part 1: Requirements
and choice of test methods
EN 17199-1, Workplace exposure - Measurement of dustiness of bulk materials that contain or release
respirable NOAA or other respirable particles - Part 1: Requirements and choice of test methods
EN 16897, Workplace exposure - Characterization of ultrafine aerosols/nanoaerosols - Determination of
number concentration using condensation particle counters
ISO 15767, Workplace atmospheres - Controlling and characterizing uncertainty in weighing collected
aerosols
ISO 27891, Aerosol particle number concentration - Calibration of condensation particle counters
3 Terms and definitions
For the purposes of this document, the terms and definitions given in EN 1540, EN 15051-1,
CEN ISO/TS 80004-2 and EN 17199-1 apply.
ISO and IEC maintain terminological databases for use in standardization at the following addresses:
• IEC Electropedia: available at http://www.electropedia.org/
• ISO Online browsing platform: available at http://www.iso.org/obp
4 Symbols and abbreviations
AES Atomic Emission Spectroscopy
CPC Condensation Particle Counter
) ®
Electrical Low Pressure Impactor
ELPI
EM Electron Microscopy
HEPA High Efficiency Particulate Arrestance
ICP Inductively coupled plasma
MFC Mass flow controller
MS Mass Spectrometry
NOAA Nano-objects, and their aggregates and agglomerates > 100 nm
RH Relative Humidity
TEM Transmission Electron Microscopy
VS Vortex Shaker
XRF X-ray Fluorescence
5 Principle
The vortex shaker method (see Annex A and Annex C) specified in this document measures the
dustiness of bulk materials in terms of
— the respirable dustiness mass fraction,
— the number-based dustiness index, and
— the number-based emission rate.
In addition, this document describes the procedures by which the aerosols can be further characterized
in terms of their particle size distributions and the morphology and chemical composition of their
airborne particles.
The sampling for the purpose of and the execution of qualitative or quantitative analysis of the
morphology and chemical composition of the collected airborne nanostructured particles are described.
Performing these analyses is optional but can provide confirmation of the sizes of the particles
generated and complementary information to the time- and size-resolving instruments.
Table 1 provides
— an overview of the different measurands, their symbols and units,
— information on whether determining these measurands is mandatory or not, and
— the aerosol instruments and sampling devices needed to determine a measurand.
®
1) ELPI is the trade name or trademark of a product supplied by Dekati. This information is given for the
convenience of users of this European Standard and does not constitute an endorsement by CEN of the product
named. Equivalent products may be used if they can be shown to lead to the same results.
Table 1 — Measurands, aerosol instruments/sampling devices and associated recommendations
for the vortex shaker method
Method/ device Mandatory/Optional
Measurand (unit)
specific to measurand
Respirable dustiness mass fraction (mg/kg) 25 mm- or 37 mm- air Mandatory
sampling cassette (see
6.2.8) mounted on a
respirable cyclone (see
6.2.7)
Number-based dustiness index of respirable Condensation Particle Mandatory
particles in the particle size range from about Counter (CPC) (see
10 nm to about 6.2.9)
1 µm (1/mg)
Number-based average emission rate of Mandatory
respirable particles in the particle size range from
about 10 nm to about
1 µm (1/mg·s)
Number of modes of the time-averaged number- Time- and size- Mandatory
based particle size distribution as dN/dlogD (-) resolving instrument
i
covering the particle
Modal aerodynamic equivalent diameters Mandatory
size range from about
corresponding to the highest mode M1 ) and to
N
10 nm up to about
the second highest mode (M2 ) of the time-
N
10 µm (see 6.2.10)
averaged number-based particle size distribution
as dN/dlogD (µm)
i
Number of modes of the time-averaged mass- Cascade impactor Optional
based particle size distribution as dM/dlogD (-) covering the particle
i
size range from about
Modal aerodynamic equivalent diameters Optional
10 nm up to about
corresponding to the highest mode (M1 ) and to
M
10 µm (see 6.2.10)
the second highest mode (M2 ) of the time-
M
averaged mass-based particle size distribution as
dM/dlogD (µm)
i
Morphological and chemical characterization of TEM-grid holder Optional
the particles including NOAA (-) equipped with porous
Carbon film may be
carbon film TEM-grid
analysed by
(see 6.2.11)
transmission electron
microscopy (TEM)
Chemical characterization of the particles 25 mm- or 37 mm- air Optional
including NOAA (-) sampling cassette
Filters may be
made from conductive
quantitatively
material (see 6.2.8)
analysed by XRF, ICP-
mounted on a
AES or ICP-MS.
respirable cyclone (see
6.2.7)
NOTE The particle size range described above is based on the equipment used during the prenormative
research.
6 Equipment
6.1 General
The test apparatus consists of an especially designed cylindrical container (see 6.2.2), in which a small
volume (0,5 cm ) of the test sample is placed that is continuously shook according a circular orbital
motion generated by the vortex shaker apparatus (see 6.2.1).
HEPA filtered air, controlled at (50 ± 5) % RH, passes through the cylindrical container at a flow rate
Q = 4,2 l/min in order to transfer the released aerosol inside the container to the sampling or
VS
measurement section.
An overview of the experimental set-up of the vortex shaker test bench is given in Figure 1.
Key
1 compressed dry air
2 mass flow controller (MFC)
3 humidification system (6.2.3) to deliver 4,2 l/min at (50 ± 5) % RH
4 high-efficiency particle arrestance (HEPA) filter cartridge
5 valve to direct incoming air flow through the cylindrical tube
6 cylindrical container (6.2.2), in which the test sample is poured
7 attachment rubber piece adapted to the design of the bottom of the container
8 vortex shaker apparatus (6.2.1) producing a circular orbital motion
9 valve to direct incoming airflow bypass the cylindrical tube
10 valve to direct outflow to the sampling and measurement section
11 tube to the sampling and measurement section (6.2.6)
Q flow rate in the vortex shaker
VS
NOTE The test bench external dimensions are about 0,6 m × 0,6 m × 0,6 m.
Figure 1 — Overview of the experimental set-up of the vortex shaker test bench
6.2 Test apparatus
6.2.1 Vortex shaker apparatus
The vortex shaker is composed of a central unit, in which an eccentric motor is located, and an
attachment rubber piece at the top to maintain the bottom of the cylindrical container (6.2.2).
As shown in Figure 1, the vertical axes of the cylindrical container, the attachment rubber piece and the
central unit shall be coaxial before starting the motor of the vortex shaker.
The vortex shaker apparatus shall produce a circular orbital motion in the horizontal plane. The motion
shall be characterized by displacement amplitude of 4 mm and a rotation speed of 1 850 r/min.
The agitation motion is created by holding the top of the container in place while allowing the bottom to
move in its circular orbital motion. Thus, the container shall be held in position by a ring located just
below the cap. The ring shall have an inner diameter of 34 mm and be made of rubber to limit the
transfer of vibrations to the rest of the test bench. It shall be held in place by an attachment piece to the
test bench.
Due the vibrations while motor running, central unit shall have resilient rubber pads. Moreover, extra
rubber elements shall be used to limit the lateral and longitudinal displacements of the central unit.
6.2.2 Cylindrical container
The characteristics of a cylindrical container are shown in Figure 2.
The cylindrical container is obtained by assembling three elements made of stainless steel material and
shown in Figure 3.
Dimensions are given in mm
Figure 2 — Characteristics of the cylindrical container used for the vortex shaker method
Dimensions are given in mm
Figure 3 — Characteristics of the three elements to be realized for the assembly of the
cylindrical container
As shown in Figure 4 a cup is screwed onto the cylindrical container. It has an inlet for incoming
particulate-free air and an outlet port through which the released aerosol escapes, which leads to the
sampling or measurement section. The tubing for the inlet and the outlet is made of stainless steel
material and has an outside diameter of 10 mm and inside diameter of 8 mm.
Dimensions are given in mm
Figure 4 — Characteristics of the inlet/outlet tubes screwed on the cylindrical container
The flow of air drawn through the cylindrical container is Q = 4,2 l/min. It ensures an injection and
VS
aspiration velocity of 1,4 m/s at the inlet and outlet respectively. The air exchange rate inside the
−1
cylindrical container is about 41 min . The Reynolds number in the inlet and outlet tubes is Re = 714,
which indicates that the flow is laminar.
6.2.3 Humidification system of incoming and dilution air
The system shall be capable of delivering 4,2 l/min of particulate-free air with controlled temperature
at (21 ± 3) °C and (50 ± 5) % RH for the incoming air in the cylindrical container (see 6.2.2). See
Figure 1.
As second humidification system capable of delivering up to 7,5 l/min of particulate-free air in the same
conditions shall be used for the dilution air prior to the time- and size-resolving instrument used for the
measurement of the number-based particle size distribution (see Figure 5).
NOTE 1 It is possible to use only one system to supply the two lines needed for the set-up described in Figure 6
in so far as the conditions of air flow, relative humidity and temperature are respected.
NOTE 2 It is suggested to have a humidification system capable of delivering particulate-free air controlled at
relative humidity within the range from 20 % RH to 90 % RH in order to be able to perform measurement under
variable relative humidity.
6.2.4 Sampling line for the measurement of the respirable dustiness mass fraction
For the determination of the respirable dustiness mass fraction configuration A of the experimental set-
up of the vortex shaker method, as shown in Figure 5, is used.
Key
1 compressed dry air
2 mass flow controller (MFC)
3 humidification system (6.2.3) to deliver QVS = 4,2 l/min at (50 ± 5) % RH
4 high-efficiency particle arrestance (HEPA) filter cartridge
5 valve to direct incoming air flow through the cylindrical tube
6 cylindrical container (6.2.2), in which the test sample is poured
7 attachment rubber piece adapted to the design of the bottom of the container
8 vortex shaker apparatus (6.2.1) producing a circular orbital motion
9 valve to direct incoming air flow bypass the cylindrical tube
10 valve to direct outflow to the sampling and measurement section
11 tube to the sampling and measurement section (6.2.6)
12 stainless steel cyclone (6.2.7) that collects the respirable aerosol fraction at 4,2 l/min
37 mm or 25 mm (two-piece open-faced configuration) air sampling cassette (6.2.8) containing a pre-weighed
filter for gravimetric analysis (6.2.14)
14 sampling pump
Q flow rate in the vortex shaker
VS
Figure 5 — Configuration A of the experimental set-up of the vortex shaker method
6.2.5 Sampling line for other measurements
For the determination of the number-based dustiness index, the number-based emission rate, the
number-based particle size distribution of the released respirable aerosol and for the collection of
released airborne particles in the respirable fraction for subsequent observations and analysis by
electron microscopy configuration B of the experimental set-up of the vortex shaker method, as shown
in Figure 6, is used.
Key
1 compressed dry air
2 mass flow controller (MFC)
3 humidification system (6.2.3) to deliver Q = 4,2 l/min at (50 ± 5) % RH
VS
4 high-efficiency particle arrestance (HEPA) filter cartridge
5 valve to direct incoming air flow through the cylindrical tube
6 cylindrical container (6.2.2), in which the test sample is poured
7 attachment rubber piece adapted to the design of the bottom of the container
8 vortex-shaker apparatus (6.2.1) producing a circular orbital motion
9 valve to direct incoming air flow bypass the cylindrical tube
10 valve to direct outflow to the sampling and measurement section
11 tube to the sampling and measurement section (6.2.6)
12 cyclone
13 aerosol flow splitter
14 time- and size-resolving aerosol instrument (6.2.10)
15 condensation particle counter (CPC) (6.2.9)
16 sampling pump
17 TEM-grid holder (6.2.11)
18 37 mm or 25 mm- (two-piece open-faced configuration) air sampling cassette (6.2.8)
containing a filter
Q flow rate in the condensed particle counter, 0,7 l/min
CPC
Q flow rate in the vortex shaker
VS
QA flow rate, 2,5 l/min
QB flowrate through the TEM-grid holder (17) or 25 ùmm-air sampling cassette (18)
Q dilution flow rate, 7,5 l/min
DIL
Figure 6 — Configuration B of the experimental set-up of the vortex shaker method
6.2.6 Conductive flexible tubing, carbon impregnated.
To minimize particle losses due to electrostatic effect in sampling lines that convey the released aerosol
to the measuring instruments and sampling devices, carbon impregnated conductive flexible tubing
shall be employed.
To minimize particles losses in sampling lines in which the released aerosol is transported to the
measuring instruments and sampling devices, tube lengths and bends in the conductive flexible tubing
shall be kept to a minimum.
6.2.7 Respirable cyclone, made of stainless steel.
A respirable cyclone is used as a sampler for sampling the respirable aerosol fraction in configuration A
(see Figure 5) and which acts as a particle size pre-separator in configuration B (see Figure 6).
The cyclone shall collect the respirable fraction, as defined in EN 481, at 4,2 l/min with a performance
as stipulated in EN 13205-2.
For configuration A (see Figure 5), the cyclone is equipped with two-piece air sampling cassettes (see
6.2.8). The assembly is then connected to a sampling pump that operates at 4,2 l/min.
For configuration B (see Figure 6), conductive flexible tubing (see 6.2.6) shall be used to connect all
parts of the instrument.
The axis of the cyclone shall be kept vertical.
6.2.8 Air sampling cassette
25 mm- or 37 mm-air sampling cassettes (two-piece open-faced configuration) containing a pre-
weighted filter for gravimetric analysis shall be used to collect particles in the respirable cyclone in
configuration A of the dustiness test (see 6.2.4 and Figure 5).
Air sampling cassettes commonly used for collection of airborne particles are prone to bypass leakage if
the cassettes are not properly assembled. Leakage around the filter will result in a loss of particles that
should have been collected onto the filter, resulting in a measurement that underestimates the mass of
released particles. Therefore, assembly of sampling cassettes shall be performed using a press. A leak
testing shall be performed in ensure proper cassette assembly.
Sampling cassettes composed of conductive materials can be used to minimize the internal deposits
that occur through static attraction.
6.2.9 Condensation particle counter (CPC), with alcohol as working fluid
A Condensation Particle Counter (CPC) shall be used for counting released airborne particles at an
aerosol flow rate Q of 0,7 l/min. The CPC shall detect airborne particles over the particle size range
CPC
from about 10 nm to greater than 1 µm and over a concentration range from 0 particles/cm to 10 000
particles/cm in single count mode.
The CPC shall be calibrated in accordance to ISO 27891 and its response checked according to
EN 16897.
6.2.10 Time- and size-resolving aerosol instrument
For the measurement of the number-based particle size distribution of the airborne particles, one time-
and size-resolving aerosol instrument covering the particle size range from about 10 nm up to about
10 µm shall be preferred over the use of two instruments, except if the two instruments measured the
same equivalent diameter (i.e. aerodynamic diameter).
The measurement of the number-based particle size distribution in aerodynamic equivalent diameter
shall be preferred and shall be performed with a time step of 1 s.
The aerosol flowrate Q should be 2,5 l/min.
A
The dilution flowrate Q should be 7,5 l/min.
DIL
NOTE 1 So far, the only instrument that can respond to these requests is the Electrical Low Pressure Impactor ®
(ELPI ). This time-resolved low pressure cascade impactor operates at 10 l/min. To prevent overloading and ®
bounce of sampled particles it is advised to use sintered oiled collection plates with the ELPI . ®
NOTE 2 In the ELPI , the number concentration in each channel is calculated from the measured current by
applying the charger efficiency curve which is dependent on mobility-equivalent diameter, itself related to the
aerodynamic diameter. Therefore, it is necessary that the density which relates these two equivalent diameters is
known to calculate the number concentration in each channel. The density mentioned here corresponds to the
effective density of airborne particles, which is theoretically dependent on particle diameter (the larger the
agglomerates and aggregates, the smaller their effective density; the closer to the primary particle diameter, the ®
closer to the material density of the compound), see [5] and [6]. Concerning the ELPI , the value considered for
the density can have a strong impact on the number concentration. Over the particle size range covered by the
® 3 3
ELPI and a range of density from 0,1 g/cm to 10 g/cm , the under estimation or overestimation can reach up to
a factor of 25. Despite this, the effect on relative particle size distributions is limited and the modal aerodynamic
equivalent diameters are therefore less affected.
The measurement of the mass-based particle size distribution using low pressure cascade impactors is
not compulsory but can provide complementary information to the number-based particle size
distribution. Low pressure cascade impactors with at least five stages below 1 µm and three stages
above 1 µm shall be preferred in order to have a good description of the particle size distribution of the
released aerosol.
6.2.11 Aerosol sampler for analytical electron microscopy analysis
For the collection of airborne particles for subsequent observations and analysis by analytical electron
microscopy, a TEM-grid holder operating at 1 l/min can be used (see Annex B). If this collection is not
carried out (as it is optional), an air sampling cassette (see 6.2.8), 25 or 37 mm, equipped with a filter
shall be used instead in order to have the same flow rates in the test apparatus. Given the generally
short sampling time (about 10 s), the use of a TEM-grid holder necessarily requires a by-pass system,
equipped with an air sampling cassette (6.2.8) in order to keep a constant flow through the respirable
selector, as shown in Figure 4.
NOTE A TEM-grid holder like the one developed by [11], and operating at 1 l/min can be used.
6.2.12 Analytical balance, capable of weighing to a resolution of 10 µg
Weighing shall be carried out according to ISO 15767.
The analytical balance shall be checked against a calibrated standard weight traceable to International
Standards at the intervals recommended by the manufacturer and immediately before weighing
sampling filter. The analytical balance shall be placed on an anti-vibration worktop. In the case where
dustiness tests are scheduled with toxic nanomaterials, the weighing operations shall be carried out in
accordance with the ad hoc prevention rules.
6.2.13 Microbalance, capable of weighing to a resolution of 1 µg
The microbalance and the sampling filters to be weighed should be placed in a room with temperature
and humidity controls within the range specified by the balance manufacturer.
Weighing shall be carried out according to ISO 15767.
The microbalance shall be checked against a calibrated standard weight at the intervals recommended
by the manufacturer and immediately before weighing sampling filter. The microbalance shall be placed
on an anti-vibration worktop. In the case where dustiness tests are scheduled with toxic nanomaterials,
the weighing operations shall be carried out in accordance with the ad hoc prevention rules.
6.2.14 Filters for gravimetric analysis
For the determination of the mass-based respirable dustiness index (see Figure 5) a filter type with a
low limit of quantification for the gravimetric analysis, typically below 15 µg, should be selected.
To obtain the limit of detection for the gravimetric analysis the procedure specified in ISO 15767 should
be applied, using a microbalance (see 6.2.13).
6.2.15 Micro-centrifuge tubes
Made of polypropylene, 1,5 ml, graduated, for preparing the test samples.
7 Requirements
7.1 General
The general procedures specified in EN 17199-1 shall be applied.
7.2 Engineering control measures
Appropriate engineering control measures (e.g. enclosure, use of local exhaust ventilation) shall be
implemented to prevent exposure of the operator during the tests, but also during disassembly and
cleaning sequences between individual test runs.
Occupational risks should be assessed according to national regulations.
NOTE The test bench has been designed so that it can be located in a ventilated enclosure especially designed
for handling powders safely to prevent exposure of the operator, both when the system is operated and also
during disassembly and cleaning sequences between each test.
7.3 Conditioning of the test material
7.3.1 General
As described in EN 17199-1, the tests can be carried out with test materials u
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