Workplace exposure - Guide for the use of direct-reading instruments for aerosol monitoring - Part 2: Evaluation of airborne particle concentrations using Optical Particle Counters

This Technical Report describes the principle underlying evaluation of one or more health related aerosol fractions using an optical particle counter and details its limits and possibilities in the field of occupational hygiene.
The method complements conventional long-term aerosol particle sampling and offers possibilities of:
-   instantaneous (direct reading) measurement;
-   time-related monitoring;
-   investigation of space-related aerosol evolution (mapping);
-   assessment of particle size distribution.
The method enables e.g.:
-   detection and relative quantification of concentration peaks due to specific operations (bagging, sanding, etc.);
-   identification of most exposed workers with a view to more detailed studies of risks and prevention measures to be applied;
-   detection of dust emission sources and their relative magnitudes.
Basically, OPCs count airborne particles and are therefore suitable for measuring concentrations expressed in number of particles per unit volume of air. The applicability of the method is limited by the particle size and concentration ranges of OPC instruments, usually approximately 10-1 µm to 101 µm and 100 particles/cm3 to 103 particles/cm3, respectively.
Depending on specific conditions, the OPC method allows filter collection of an aerosol fraction, in the best case close to a health-related fraction (see EN 481), provided the OPC has the relevant sampling efficiency over its optical particle size range. If this is not the case, at least a sufficient aspiration efficiency is required to cover the size range of particles which can be detected and measured by the OPC optical system.
Converting count-based particle number concentrations into mass concentrations based on estimated particle size is indirect and therefore the accuracy of the conversion is limited by several simplifying assumptions:
-   identical optical parameters for both the calibration aerosol and the measured workplace aerosol;
-   (...)

Exposition am Arbeitsplatz - Leitfaden für die Anwendung direkt anzeigender Geräte zur Überwachung von Aerosolen - Teil 2: Ermittlung der Konzentration Luft getragener Partikel mit optischen Partikelzählern

Exposition au poste de travail - Guide d'utilisation des instruments à lecture directe pour la surveillance des aérosols - Partie 2 : Evaluation des concentrations de particules en suspension dans l'air à l'aide de compteurs optiques de particules

Le présent Rapport Technique du CEN décrit le principe de l'évaluation d'une ou plusieurs fractions d'aérosols liées à la santé à l'aide d'un compteur optique de particules et en précise les limites et les possibilités dans le cadre de l'hygiène du travail.
Complémentaire de l'échantillonnage classique de longue durée des particules d'aérosols, cette méthode offre des possibilités :
-   de mesurage quasi instantané (lecture directe) ;
-   de surveillance dans le temps ;
-   d'examen des variations spatiales des aérosols (cartographie) ;
-   d'évaluation de la distribution granulométrique.
A titre d'exemples, cette méthode permet :
-   la détection et la quantification relative des pics de concentration dus à des opérations spécifiques (ensachage, ponçage, etc.) ;
-   l'identification des travailleurs les plus exposés en vue d'études plus approfondies des risques et des mesures de prévention à appliquer ;
-   la détection des sources d'émission de poussières et leurs importances relatives.
Fondamentalement, les COP effectuent un comptage de particules en suspension dans l'air et sont donc adaptés au mesurage des concentrations exprimées en nombre de particules par unité de volume d'air. L'applicabilité de la méthode est limitée par les gammes de tailles de particules et de concentrations des appareils de COP qui, en général, sont respectivement de l'ordre de 10-1 µm à 101 µm et 100 particules/cm3 à 103 particules/cm3.
La méthode de COP permet, moyennant certaines conditions, de collecter sur un filtre une fraction de l'aérosol, proche dans le meilleur cas de la fraction liée aux problèmes de santé (voir EN 481), à condition que le COP ait une efficacité de captage pertinente sur sa gamme optique de taille de particules. Si tel n'est pas le cas, une efficacité d'aspiration suffisante est au moins requise pour couvrir la classe granulométrique des particules qui peuvent être détectées et mesurées par le système optique du COP.

Izpostavljenost na delovnem mestu - Vodilo za uporabo instrumentov z neposrednim odčitavanjem za monitoring aerosolov - 2. del: Vrednotenje koncentracije lebdečih delcev z uporabo optičnih števcev delcev

To tehnično poročilo opisuje načelo, ki je podlaga za vrednotenje enega ali več z zdravjem povezanih aerosolnih frakcij z uporabo optičnih števcev delcev ter podrobno opisuje omejitve in možnosti na področju higiene pri delu. Ta metoda dopolnjuje konvencionalno dolgoročno vzorčenje aerosolnih delcev in ponuja možnosti za: takojšnje merjenje (z neposrednim odčitavanjem); časovni monitoring; raziskovanje prostorske sprostitve aerosolov (preslikava); ocenjevanje razporeditve velikosti delcev. Metoda na primer omogoča: zaznavanje in relativno količinsko določanje največjih vrednosti koncentracije zaradi določenih delovanj (polnjenja v vreče, brušenje itd.); prepoznavanje najbolj izpostavljenih delavcev za izvedbo bolj podrobnih študij o tveganjih in preventivnih ukrepih; zaznavanje virov emisij prahu in njihovih relativnih razsežnosti. V bistvu OPC štejejo lebdeče delce in so potemtakem primerni za merjenje koncentracij, izraženih v številu delcev na enoto volumna zraka. Uporaba metode je omejena z velikostjo delca in razponi koncentracije  inštrumentov OPC, ki so običajno od 10-1 μm do 101 μm  in od 100 delcev/cm3 do 103 delcev/cm3. Odvisno od posebnih pogojev, metoda OPC omogoča zbiranje aerosolne frakcije s filtrom, v najboljšem primeru blizu z zdravjem povezani frakciji (glej EN 481), pod pogojem, da je OPC ustrezno učinkovit pri vzorčenju optičnega razpona velikosti delcev. Če temu ni tako, se zahteva vsaj zadostna učinkovitost pri izsesavanju, ki zajema razpon velikosti delcev, ki ga OPC optični sistem lahko zazna in meri. Pretvorba koncentracij števila delcev, osnovanih na štetju, v masno koncentracijo, osnovano na ocenjeni velikosti delcev, je neposredna; potemtakem je natančnost pretvorbe omejena z več naslednjimi poenostavitvenimi predpostavkami: identični optični parametri za aerosol pri kalibraciji in aerosol, merjen na delovnem mestu; vsi prešteti delci aerosola na delovnem mestu so okrogli z geometričnim premerom, enakim določenemu optičnemu premeru in z identično gostoto; učinkovitost OPC pri izsesavanju in prenosu je poznana ali ocenjena glede na inženirske modele. Potemtakem je potrebna potrditev ocenjene masne koncentracije iz OPC porazdelitve velikosti delcev z konvencionalno metodo vzorčenja. Ocenjene masne koncentracije glede na podatke OPC so zgolj pokazatelj in se jih ne more uporabiti za neposredno primerjavo z pravno uveljavljenimi mejami poklicne izpostavljenosti.

General Information

Status
Published
Publication Date
25-May-2010
Current Stage
9093 - Decision to confirm - Review Enquiry
Completion Date
12-Jun-2015

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SLOVENSKI STANDARD
01-november-2010
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NRQFHQWUDFLMHOHEGHþLKGHOFHY]XSRUDERRSWLþQLKãWHYFHYGHOFHY
Workplace exposure - Guide for the use of direct-reading instruments for aerosol
monitoring - Part 2: Evaluating airborne particle concentrations using Optical Particle
Counters
Exposition am Arbeitsplatz - Leitfaden für die Anwendung direkt anzeigender Geräte zur
Überwachung von Aerosolen - Teil 2: Ermittlung der Konzentration Luft getragener
Partikel mit optischen Partikelzählern
Exposition au poste de travail - Guide d'utilisation des instruments à lecture directe pour
la surveillance des aérosols - Partie 2 : Evaluation des concentrations de particules en
suspension dans l'air à l'aide de compteurs optiques de particules
Ta slovenski standard je istoveten z: CEN/TR 16013-2:2010
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.

TECHNICAL REPORT
CEN/TR 16013-2
RAPPORT TECHNIQUE
TECHNISCHER BERICHT
May 2010
ICS 13.040.30
English Version
Workplace exposure - Guide for the use of direct-reading
instruments for aerosol monitoring - Part 2: Evaluation of
airborne particle concentrations using Optical Particle Counters
Exposition au poste de travail - Guide d'utilisation des Exposition am Arbeitsplatz - Leitfaden für die Anwendung
instruments à lecture directe pour la surveillance des direkt anzeigender Geräte zur Überwachung von Aerosolen
aérosols - Partie 2 : Evaluation des concentrations de - Teil 2: Ermittlung der Konzentration Luft getragener
particules en suspension dans l'air à l'aide de compteurs Partikel mit optischen Partikelzählern
optiques de particules
This Technical Report was approved by CEN on 13 March 2010. It has been drawn up by the Technical Committee CEN/TC 137.

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, Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland and United Kingdom.

EUROPEAN COMMITTEE FOR STANDARDIZATION
COMITÉ EUROPÉEN DE NORMALISATION

EUROPÄISCHES KOMITEE FÜR NORMUNG

Management Centre: Avenue Marnix 17, B-1000 Brussels
© 2010 CEN All rights of exploitation in any form and by any means reserved Ref. No. CEN/TR 16013-2:2010: E
worldwide for CEN national Members.

Contents Page
Foreword .4
Introduction .5
1 Scope .6
2 Principles of the method .7
2.1 Light scattering .7
2.2 Working principle.7
3 OPC performance characteristics .8
4 Number and mass concentrations .8
5 Mass concentrations of thoracic and respirable aerosol fractions .9
6 OPC use . 10
6.1 General . 10
6.2 Airflow adjustment. 11
6.3 Calibration of particle count response . 11
6.4 Calibration of particle diameter response . 11
6.5 Mass concentration response . 11
7 Fundamental and practical limitations . 12
7.1 Refraction index and particle density . 12
7.2 Forward scattering instruments . 12
7.3 Limitation in particle size . 12
7.4 Coincidence error and concentration limitation . 12
7.5 Aerosols from several sources . 12
8 Instrumentation characteristics . 13
8.1 Aspiration system . 13
8.2 Integrated collection filter . 13
8.3 Sampling head . 13
8.4 Optical cell . 13
8.5 Electronics . 13
8.6 Case of laser instruments . 13
9 Aerosol measurement by OPC . 13
9.1 Operating procedure . 13
9.2 Cartography of workplace . 14
9.3 Working shift monitoring . 14
9.4 Sampling record. 14
9.5 Cleaning and maintenance . 14
Annex A (informative) Evaluation of an OPC as an instrument for thoracic and respirable mass
concentrations . 15
A.1 Introduction to workplace evaluation . 15
A.2 Procedure for field comparison of the OPC with the reference sampler . 15
A.2.1 General . 15
A.2.2 Comparison of a static OPC with a static reference sampler . 16
A.2.3 Comparison of mass concentrations for the respirable or thoracic aerosol fractions
calculated from OPC data with a reference sampler . 16
A.3 Calculation methods . 16
A.3.1 General . 16
A.3.2 Estimation of the correction coefficient . 16
A.3.3 Exclusion of outliers . 17
A.3.4 Residual uncertainty after transformation by the correction function . 17
A.3.5 Equivalence . 17
A.4 Periodic validation . 17
A.5 Documentation . 18
A.5.1 General . 18
A.5.2 Description of the OPC and the reference sampler . 18
A.5.3 Critical review of sampling process . 18
A.5.4 Circumstances of field comparison . 18
A.5.5 Details of experimental design . 18
A.5.6 Data analysis . 18
A.5.7 Equivalence . 19
A.6 Nomenclature . 19
Annex B (informative) Example for the determination of the correction coefficient for an OPC . 20
Bibliography . 23

Foreword
This document (CEN/TR 16013-2:2010) 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.
Attention is drawn to the possibility that some of the elements of this document may be the subject of patent
rights. CEN [and/or CENELEC] shall not be held responsible for identifying any or all such patent rights.
CEN/TR 16013, Workplace exposure ― Guide for the use of direct-reading instruments for aerosol
monitoring, consists of the following parts:
 Part 1: Choice of monitor for specific applications
 Part 2: Evaluation of airborne particle concentrations using Optical Particle Counters
 Part 3: Evaluation of airborne particle concentrations using photometers (in preparation)
Introduction
Optical Particle Counters (OPC) count airborne particles and are therefore suitable for measuring
concentrations expressed in number of particles per unit volume of air. Counting-based measurement of mass
concentration and particle size estimation is indirect: a number of assumptions and approximations are made
to access the information sought. Nevertheless, optical particle counters can be used to evaluate the
efficiency of preventive actions and to monitor the spatial distribution and/or the temporal evolution of an
aerosol. In occupational hygiene, no standard recommends workers' exposure assessment using optical
particle counters. These instruments should instead be considered as permitting a complementary approach
to the conventional filter-based gravimetric method. A confirmation of OPC mass concentration by a
conventional sampling method with a calibrated instrument is recommended when comparing concentration
measurements with legal limit values.
An OPC method allows assessment of working place aerosol conditions including:
 almost instantaneous evaluation of particle concentration and size distribution;
 estimating concentration variations and mean concentration of aerosol particles during a working shift
period;
 sampling to constitute a particle sample for further analysis (when equipped with terminal filter).
1 Scope
This Technical Report describes the principle underlying evaluation of one or more health related aerosol
fractions using an optical particle counter and details its limits and possibilities in the field of occupational
hygiene.
The method complements conventional long-term aerosol particle sampling and offers possibilities of:
 instantaneous (direct reading) measurement;
 time-related monitoring;
 investigation of space-related aerosol evolution (mapping);
 assessment of particle size
...

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