SIST-TP CEN/TR 15547:2008

SLOVENSKI STANDARD
SIST-TP CEN/TR 15547:2008
01-marec-2008
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Workplace atmospheres - Calculation of the health-related aerosol fraction concentration
from the concentration measured by a sampler with known performance characteristics
Arbeitsplatzatmosphäre - Berechnung der gesundheitsbezogenen Fraktion der
Aerosolkonzentration anhand der mit einem Probenahmegerät mit bekannten
Leistungseigenschaften gemessenen Konzentration
Atmospheres des lieux de travail - Calcul de la concentration en fractions d'aérosols
liées a la santé a partir de la concentration mesurée a l'aide d'un dispositif de
prélevement ayant des caractéristiques de performances connues
Ta slovenski standard je istoveten z: CEN/TR 15547:2007
ICS:
13.040.30
SIST-TP CEN/TR 15547:2008 en
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

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TECHNICAL REPORT
CEN/TR 15547
RAPPORT TECHNIQUE
TECHNISCHER BERICHT
February 2007
ICS 13.040.30

English Version
Workplace atmospheres - Calculation of the health-related
aerosol fraction concentration from the concentration measured
by a sampler with known performance characteristics
Atmosphères des lieux de travail - Calcul de la Arbeitsplatzatmosphäre - Berechnung der
concentration en fractions d'aérosols liées à la santé à gesundheitsbezogenen Fraktion der Aerosolkonzentration
partir de la concentration mesurée à l'aide d'un dispositif de anhand der mit einem Probenahmegerät mit bekannten
prélèvement ayant des caractéristiques de performances Leistungseigenschaften gemessenen Konzentration
connues
This Technical Report was approved by CEN on 4 December 2006. It has been drawn up by the Technical Committee CEN/TC 137.
CEN members are the national standards bodies of Austria, Belgium, Bulgaria, 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: rue de Stassart, 36  B-1050 Brussels
© 2007 CEN All rights of exploitation in any form and by any means reserved Ref. No. CEN/TR 15547:2007: E
worldwide for CEN national Members.

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CEN/TR 15547:2007 (E)
Contents Page
Foreword.3
Introduction .4
1 Scope.5
2 Normative references.5
3 Method to produce improved concentration data.5
4 Data needed to calculate the concentration of a health-related aerosol fraction.6
5 Calculation method.6
Annex A (informative) Numerical example of calculation.9
Annex B (informative) Field sampling example .12
Bibliography .14

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CEN/TR 15547:2007 (E)
Foreword
This document (CEN/TR 15547:2007) 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 shall not be held responsible for identifying any or all such patent rights.
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CEN/TR 15547:2007 (E)
Introduction
Exposure assessment of workers to particulate matter dispersed into the air at the workplace is generally
achieved through aerosol sampling by using instruments designed for measuring health-related aerosol
fractions as defined in EN 481. EN 13205 gives a methodology to evaluate sampler performance. The
knowledge of the sampling efficiency of a sampler is used to calculate the bias and the accuracy in
concentration for log-normally distributed aerosols. Bias and accuracy maps give an overall indication on
sampler performance when sampling health-related aerosol fractions. This performance varies with particle
size distribution of sampled aerosol.
Many different samplers can be used for the same purpose, depending on local circumstances or the current
practice in the country where these measurements have to be performed. Even with samplers whose
performances are quite similar, some significant differences in measured concentrations can occur between
these samplers, depending on the aerosol measured. Furthermore, the concentration measured by a sampler
is not actually the conventional concentration even if the sampler fulfils the performance criteria stated in
EN 13205. This is due to the fact that the particle-size selectivity of the sampler does not generally coincide
exactly with the conventional sampling curve over the whole particle-size range.
In the revision of EN 482 presently under way, the uncertainty estimate of a measurement procedure should
be expanded to meet the requirements of ENV 13005 complying with GUM (ISO Guide to the expression of
Uncertainty in Measurements). This requires that all uncertainties encountered by the use of a measurement
procedure (except interlaboratory variation) have to be accounted for. For the special case of aerosol
sampling this means that the uncertainty in an expected bias of the sample due to non-ideal collection
characteristics will only be estimated for a very wide range of size distributions. The calculations presented in
this Technical Report can help to significantly reduce this uncertainty by first estimating a restricted range of
size distributions in which the sampler was actually used, and then estimate the bias uncertainty only over this
narrow range of size distributions. For an aerosol sampler, the variability due to bias is in many cases a major
component of the uncertainty.
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CEN/TR 15547:2007 (E)
1 Scope
This Technical Report specifies a method for calculating and expressing the relevant aerosol fraction
concentration and its confidence interval, rather than the actually measured concentration. This can be done
for any sampler satisfying EN 13205:2001, Annex A.
The calculation method follows the way developed and described in EN 13205:2001, Annex A and Annex F.
This Technical Report explains practically how to perform the calculation.
2 Normative references
The following referenced documents are indispensable for the application of this document. For dated
references, only the edition cited applies. For undated references the latest edition of the referenced
document (including any amendments) applies.
EN 13205:2001, Workplace atmospheres — Assessment of performance of instruments for measurement of
airborne particle concentrations.
3 Method to produce improved concentration data
The method is based on the knowledge of sampler’s particle size-selectivity and the estimation of the aerosol
size distribution. The results with lowest uncertainty are obtained when the concentration measurements are
accompanied by measurement of aerosol size distribution. When the size distribution is not known, an
estimate can be used. The accuracy of this estimation will have a direct influence on the confidence interval of
the concentration value. The estimation of particle size distribution is not an easy exercise, however in many
cases the knowledge of the aerosol nature (mineral dust, fumes, oil mists, etc.) allows an approximate
estimation to be made.
This approach facilitates a comparison measured health-related aerosol concentrations obtained in different
European countries, whatever the samplers used.
The method cannot be used to calculate the respirable aerosol fraction from the thoracic aerosol fraction, or
vice versa.
Using the aerosol concentration measured by a sampler and the information provided by the application of
EN 13205, it is possible to calculate the concentration of the aerosol conventional fraction of interest and
therefore to assess the exposure as mentioned in EN 689 independently of the sampler used. This calculation
method leads to less bias relative to the intended conventional health-related aerosol fraction (see [1]).
Using the calculation described in this document is not compulsory. However, there are several circumstances
when using the proposed method could help to obtain higher quality results from routine aerosol
measurements. Of course, there is no need to use this calculation when the selectivity of the aerosol sampler
meets exactly the conventional target curve, i.e. its performance is ideal for all particle sizes.
More accurate values of aerosol concentrations related to some conventional fraction can be needed in some
special cases:
 in epidemiological studies consistent exposure data from old and recent periods of time are
simultaneously required in order to be correlated with human health effects;
 when data from various sampling techniques and different countries need to be interpreted. The proposed
method helps to make the results of measurements more consistent by recalculating them in terms of
concentrations of the relevant health-related aerosol fraction. The method allows a comparison of
exposures measured at different times and work places provided the performances of the samplers used
are known.
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CEN/TR 15547:2007 (E)
Another case where the proposed method can be useful is the measurement of aerosol concentrations in the
vicinity of Limit Values. A Limit Value for an aerosol concentration in the workplace is not defined as
concentration measured by some sampling device but precisely as a concentration of one of three
conventional health-related aerosol fractions (see EN 481). The method is an approach to assess the right
concentration to be compared with its Limit Value.
In the case of simultaneous measurements with two or several different samplers, the measured values from
all techniques can be processed with the proposed calculation method. The common part of the individual
confidence intervals represents a narrower confidence interval of the conventional concentration than that of
any individual measurement. The confidence interval improvement is achieved even when the sampler
performances are rather poor.
The calculations suggested in this document will not reduce the variability in measured concentration due to
the inherent variability of the concentration at a workplace
4 Data needed to calculate the concentration of a health-related aerosol fraction
a) Data from the laboratory evaluation of the sampler performance according to EN 13205:2001, Annex A.
The evaluation gives the particle size dependent sampling bias (∆) along with its standard deviation due
to the experimental method σ(∆).
b) Workplace sampling data as sampled particle mass (M), sampling flow rate (Q) and time of sampling (t)
along with the standard deviation of the analytical method e.g. weighing, σ(M), and the relative standard
deviation of the flow rate, RSD(Q).
c) Distribution of particle mass vs. particle aerodynamic diameter of sampled aerosol, measured or
estimated. This could be a log-normal distribution expressed by parameters MMAD and GSD (Mass
Median Aerodynamic Diameter and Geometric Standard Deviation) as written in EN 13205. When the
aerosol size distribution is measured at the workplace (e.g. using a cascade impactor), single values of
the MMAD and the GSD will be determined. When the size-distribution measurement cannot be provided,
the estimation of these parameters can be expressed as intervals: [MMAD – MMAD ] and [GSD –
min max min
GSD ], where MMAD < 25 µm.
max max
NOTE In some cases the workplace aerosol is better represented by a bi-modal particle size distribution. The bi-
modal distribution can be modelled by two combined uni-modal distributions and a parameter “k” from the range [0;1]
representing the relative weight of each mode . If the distribution function of the first mode is Y =ƒ(D) and the distribution
1
function of the second mode is Y =ƒ(D), the bi-modal aerosol distribution Y can be written as:
2
Y = kY +()1 −k Y (1)
1 2
The more precise the knowledge of the sampler performance and aerosol size-distribution data is, the less
uncertainty there will be in the estimated concentration of the health-related aerosol fraction. Quality of
sampling performance data may vary with the sampled aerosol fraction. Sampling the respirable and thoracic
fractions is less wind-dependent and therefore, the experimental sampling efficiency measurements are
generally of higher quality for these fractions than for the inhalable fraction. This is due to the high inertia of
coarse particles involved in the inhalable aerosol sampling.
5 Calculation method
The concentration C* of a specified conventional fraction of an aerosol is given by:
∞
* *
C =Cf (D)E (D)dD (2)
M
∫
0
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CEN/TR 15547:2007 (E)
where
C is the total aerosol concentration;
f the particle-size mass distribution;
M
E* is the function defining the conventional probability for particles to penetrate some compartments of
the respiratory airways (see EN 481).
f and E are functions of particle aerodynamic diameter D. Any actual sampler (index i) is characte
...