EN 482:2006

SLOVENSKI STANDARD
01-januar-2007
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SIST EN 482:1998
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Workplace atmospheres - General requirements for the performance of procedures for
the measurement of chemical agents
Arbeitsplatzatmosphäre - Allgemeine Anforderungen an die Leistungsfähigkeit von
Verfahren zur Messung chemischer Arbeitsstoffe
Atmospheres des lieux de travail - Exigences générales concernant les performances
des procédures de mesurage des agents chimiques
Ta slovenski standard je istoveten z: EN 482:2006
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.

EUROPEAN STANDARD
EN 482
NORME EUROPÉENNE
EUROPÄISCHE NORM
August 2006
ICS 13.040.30 Supersedes EN 482:1994
English Version
Workplace atmospheres - General requirements for the
performance of procedures for the measurement of chemical
agents
Atmosphères des lieux de travail - Exigences générales Arbeitsplatzatmosphäre - Allgemeine Anforderungen an die
concernant les performances des modes opératoires de Leistungsfähigkeit von Verfahren zur Messung chemischer
mesurage des agents chimiques Arbeitsstoffe
This European Standard was approved by CEN on 7 July 2006.
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 Central Secretariat 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 Central Secretariat has the same status as the official
versions.
CEN members are the national standards bodies of Austria, Belgium, 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
© 2006 CEN All rights of exploitation in any form and by any means reserved Ref. No. EN 482:2006: E
worldwide for CEN national Members.

Contents Page
Foreword.4
1 Scope .6
2 Normative references .6
3 Terms and definitions .7
4 Classification.9
4.1 General.9
4.2 Screening measurements of time weighted average concentration.9
4.3 Screening measurements of variation of concentration in time and/or space .9
4.4 Measurements for comparison with (occupational exposure) limit values and periodic
measurements.9
5 Performance requirements .10
5.1 Screening measurements of time weighted average concentration.10
5.2 Screening measurements of variation of concentration in time and/or space .10
5.3 Measurements for comparison with limit values and periodic measurements .10
5.4 Composite procedures.11
5.5 Transport and storage.11
5.6 Environmental conditions.11
5.7 Description of measuring procedure.12
5.8 Dimension of result .12
5.9 Additional requirements .12
6 Test method.12
7 Validation report .13
Annex A (informative) Measurement categories described in EN 689 and involving a combination
of measurement tasks.14
A.1 Worst case measurements .14
A.2 Fixed point measurements .14
A.3 Short-term peak measurements.14
Annex B (informative) Structure of a method description .15
Annex C (informative) Calculation of uncertainty of measurement .16
C.1 General.16
C.2 Uncertainty associated with sampled air volume .16
C.2.1 Pumped sampling.16
C.2.2 Diffusive sampling.18
C.3 Uncertainty associated with sampling efficiency.18
C.3.1 Pumped sampling methods for gases and vapours .18
C.3.2 Diffusive sampling methods for vapours.18
C.3.3 Aerosol sampling methods.19
C.4 Uncertainty associated with sample storage and transportation.21
C.4.1 Sample storage .21
C.4.2 Transportation.21
C.5 Uncertainty associated with analytical recovery.21
C.5.1 Gases and vapours.21
C.5.2 Measurement of chemical agents in airborne particles .23
C.6 Uncertainty associated with analytical variability.24
C.6.1 General.24
C.6.2 Estimation using repeatability data .24
C.6.3 Estimation using within-laboratory reproducibility data.25
C.6.4 Blank subtraction .26
C.7 General equation for combination of uncertainty components .26
Bibliography.27

Foreword
This document (EN 482:2006) 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 February 2007, and conflicting national standards shall be withdrawn
at the latest by February 2007.
This document supersedes EN 482:1994.
The major technical change between this European Standard and the previous edition is the revision of the
method of calculating the uncertainty of a measurement procedure to comply with ENV 13005.
According to the CEN/CENELEC Internal Regulations, the national standards organizations of the following
countries are bound to implement this European Standard: Austria, Belgium, 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.
Introduction
National laws and regulations based on European Directives require the assessment of the potential worker
exposure to chemical agents in workplace atmospheres. One way of assessing such exposure is to measure
the concentration of a chemical agent in the air in the worker's breathing zone. The procedures used for such
measurements should give reliable and valid results so that when compared with set occupational exposure
limit values a correct decision can be made, for instance, as to whether the exposure level is acceptable or
control measures need to be applied.
Because of their importance in the process of exposure assessment, it is required that the measurement
procedures should fulfil some general requirements, which are given in this document. Specific European
Standards have been prepared for different types of measuring procedures and measuring devices. These
include European Standards for dust samplers (EN 13205), diffusive samplers (EN 838), sorption tubes for
active sampling (EN 1076), detector tubes (EN 1231), sampling pumps (EN 1232, EN 12919), metals and
metalloids (EN 13890), mixtures of airborne particles and vapours (ENV 13936) and direct reading
instruments (EN 45544 all parts). In these specific European Standards additional requirements have been
included for the procedure or device in question, so that the general requirements of this document are not
compromised. Where no specific European Standard exists, only the general requirements apply.
Performance requirements are given in this document for unambiguity, selectivity, expanded uncertainty for
minimum specified measuring ranges, averaging time, etc. These requirements are intended to apply under
environmental conditions present at the workplace. However, because a wide range of environmental
conditions is encountered in practice, this document specifies requirements that have to be fulfilled by
measuring procedures when tested under prescribed laboratory conditions.
It is the user's responsibility to choose appropriate procedures or devices that meet the requirements of this
document. One way of doing this is to obtain information or confirmation from the provider of a procedure or
the manufacturer of a device. Type-testing, or more generally, assessment of the performance of procedures
or devices, can be undertaken by the manufacturer, user, test house or research and development laboratory,
as is most appropriate. A number of existing procedures for workplace measurements have been tested over
part of the required minimum specified measuring range but not over the entire range (see Table 1) or have
not been tested for all environmental influences and potential interference's. If these partially validated
procedures meet the performance requirements of this European Standard they can nevertheless be used at
present. These procedures should be tested over the full ranges as soon as is reasonably practicable. If there
is no measuring procedure for a chemical agent, which meet the requirements of this document, a procedure
should be used, whose performance is nearest the specified requirements.
1 Scope
This document specifies general performance requirements for procedures for determination of the
concentration of chemical agents in workplace atmospheres as required by the Chemical Agents Directive
98/24/EC (see [1]). These requirements apply to all measuring procedures, irrespective of the physical form of
the chemical agent (gas, vapour, suspended matter) and of the sampling method and analytical method used.
This document is applicable to all steps of a measuring procedure.
This document is applicable to measuring procedures with separate sampling and analysis steps, and also to
direct-reading devices.
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 applies.
EN 838:1995, Workplace atmospheres – Diffusive samplers for the determination of gases and vapours –
Requirements and test methods
EN 1076:1997, Workplace atmospheres – Pumped sorbent tubes for the determination of gases and
vapours – Requirements and test methods
EN 1231, Workplace atmospheres – Short term detector tube measurement systems – Requirements and test
methods
EN 1232, Workplace atmospheres – Pumps for personal sampling of chemical agents – Requirements and
test methods
EN 1540, Workplace atmospheres – Terminology
EN 12919, Workplace atmospheres – Pumps for the sampling of chemical agents with a volume flow rate of
over 5 l/min – Requirements and test methods
EN 13205:2001, Workplace atmospheres – Assessment of performance of instruments for measurement of
airborne particle concentrations
EN 13890, Workplace atmospheres – Procedures for measuring metals and metalloids in airborne particles –
Requirements and test methods
EN 45544 (all parts), Workplace atmospheres – Electrical apparatus used for the direct detection and direct
concentration measurement of toxic gases and vapours
ISO 78-2, Chemistry – Layouts for standards – Part 2: Methods of chemical analysis
3 Terms and definitions
For the purposes of this document, the terms and definitions given in EN 1540 and the following apply.
3.1
analytical uncertainty
u
a
combined uncertainty of the analytical procedure including, where relevant, contributions from analytical
recovery, analytical variability, interferences, calibration, instrument response drift and blank correction
3.2
averaging time
period of time for which the measuring procedure yields a single value
[EN 1540:1998]
NOTE For direct reading instruments the averaging time is related to the internal electrical time constant. For other
procedures it is normally equal to the sampling time.
3.3
bias
consistent deviation of the measured value from the value of the air quality characteristic itself or the accepted
reference value
[ISO 6879:1995]
NOTE 1 In this European Standard the "air quality characteristic" means the concentration of a chemical agent in air.
NOTE 2 In this European Standard the “accepted reference value” can be, for example, the certified value of a
reference material, the concentration of a standard test atmosphere or the target value of an interlaboratory comparison.
3.4
chemical agent
any chemical element or compound on its own or admixed as it occurs in the natural state or as produced,
used, or released, including release as waste, by any work activity, whether or not produced intentionally and
whether or not placed on the market
[Council Directive 98/24/EC Art. 2(a) [1]]
3.5
coverage factor
k
numerical factor used as a multiplier of the combined standard uncertainty in order to obtain an expanded
uncertainty
NOTE A coverage factor, k , is typically in the range from 2 to 3.
[ENV 13005:1999]
3.6
combined standard uncertainty
u
c
standard uncertainty of the result of a measurement when that result is obtained from the values of a number
of other quantities, equal to the positive square root of a sum of terms, the terms being the variances or
covariances of these other quantities weighted according to how the measurement result varies with changes
in these quantities
[ENV 13005:1999]
3.7
expanded uncertainty
U
quantity defining an interval about the result of a measurement, that may be expected to encompass a large
fraction of the distribution of values that could reasonably be attributed to the measurand
[ENV 13005:1999]
3.8
(occupational exposure) limit value
limit of the time-weighted average of a chemical agent in the air within the breathing zone of a worker in
relation to a specified reference period
[Council Directive 98/24/EC Art. 2(d) [1]]
NOTE Limit values are mostly set for reference periods of 8 h, but can also be set for shorter periods or
concentration excursions. Limit values for gases and vapours are stated in terms independent of temperature and air
pressure variables in ml/m³ and in terms dependent on those variables in mg/m³ for a temperature of 20 °C and a pressure
of 101,3 kPa. Limit values for suspended matter and mixtures of particles and vapours are given in mg/m³ or multiples of
that for actual environmental conditions (temperature, pressure) at the workplace. Limit values of fibres are given in
number of fibres/m³ or number of fibres/cm³ for actual environmental conditions (temperature, pressure) at the workplace.
3.9
measurand
particular quantity subject to measurement
[ENV 13005:1999]
3.10
non-random uncertainty
uncertainty associated with systematic errors
3.11
random uncertainty
uncertainty associated with random errors
3.12
repeatability conditions
conditions where independent test results are obtained by the same method on identical test items in the
same laboratory by the same operator using the same equipment within short intervals of time
[ISO 3534-1:1993]
3.13
reproducibility conditions
conditions where test results are obtained by the same method on identical test items in different laboratories
with different operators using different equipment
[ISO 3534-1:1993]
3.14
sampling uncertainty
u
s
combined uncertainty of the sampling procedure including, where relevant, contributions from sampled air
volume, sampling efficiency, sample storage and, if applicable, transport
3.15
standard uncertainty
uncertainty of the result of a measurement expressed as a standard deviation
[ENV 13005:1999]
3.16
uncertainty (of measurement)
parameter, associated with the result of a measurement, that characterizes the dispersion of the values that
could reasonably be attributed to the measurand
[ENV 13005:1999]
4 Classification
4.1 General
In this document measuring procedures are classified according to measurement task. This classification is
based upon the measurement strategy laid down in EN 689.
NOTE EN 689 describes a number of measurement categories that involve a combination of these measurement
tasks (see Annex A).
4.2 Screening measurements of time weighted average concentration
Screening measurements of time weighted average concentration are performed to obtain relatively crude
quantitative information on exposure levels in order to decide if an exposure problem exists, and if so, to
appraise its possible seriousness. These measurements can also determine if the exposure is well below or
well above the (occupational exposure) limit value.
4.3 Screening measurements of variation of concentration in time and/or space
Screening measurements of variation of concentration in time and/or space are used to:
 provide information on the likely pattern of the concentration of chemical agents in air;
 identify locations and periods of elevated exposure;
 provide information on the location and intensity of emission sources;
 estimate the effectiveness of ventilation or other technical measures.
4.4 Measurements for comparison with (occupational exposure) limit values and periodic
measurements
Measurements for comparison with (occupational exposure) limit values are used to obtain results of known
precision and accuracy for the average concentration of a chemical agent in the air in a worker’s breathing
zone.
Periodic measurements are used to determine whether exposure conditions have changed since the
measurements for comparison with limit values were performed, or whether control measures remain effective
(see EN 689).
NOTE Since the composition of the workplace atmosphere will have been investigated during the initial occupational
exposure assessment, it might be appropriate for periodic measurements to use procedures with lower selectivity.
5 Performance requirements
NOTE Performance requirements for measuring procedures depend on the measurement task. The performance
requirements for screening measurements are less stringent than for measurements for the comparison with limit values
and periodic measurements. Therefore, the performance requirements for screening measurements in 5.1 and 5.2 are
only given in general terms.
5.1 Screening measurements of time weighted average concentration
The measurement procedures shall have:
 adequate selectivity for the chemical agent (see 4.2);
 averaging time less than or equal to the limit value reference period;
 measuring range that includes the limit value;
 expanded uncertainty that is fit for purpose (see 4.2).
5.2 Screening measurements of variation of concentration in time and/or space
The measuring procedures shall have:
 adequate selectivity for the chemical agent (see 4.3);
 short averaging time (for variation of concentration in time ≤ 5 min; for variation of concentration in
space ≤ 15 min);
 measuring range that is fit for purpose (see 4.3);
 expanded uncertainty that is fit for purpose (see 4.3).
5.3 Measurements for comparison with limit values and periodic measurements
5.3.1 Unambiguity
A measuring procedure shall produce an unambiguous result for the concentration of the chemical agent
being measured in the specified measuring range, i.e. an analytically determined value shall correspond to
one concentration only.
5.3.2 Selectivity
The measuring procedure shall contain appropriate information about the nature and magnitude of any
interferences.
NOTE Selectivity requirements vary from case to case, depending on what is known in advance about the workplace
air. If the identity of all contaminants present is not known in advance then the measuring procedure will need to have a
high selectivity. If the identity of all contaminants is known prior to measurement, and there are no interferents present,
then it might be possible to use a measurement method with a low selectivity.
Procedures for measuring chemical agents present as airborne particles shall prescribe a method for
sampling the particle size fraction, as defined in EN 481, for which the limit value for the chemical agent is set.
If different limit values are set for different species of a chemical agent, then the measuring procedure shall
determine the individual species concerned.
5.3.3 Averaging time
The averaging time is equal to the sampling time, which shall be less than or equal to limit value reference
period.
5.3.4 Measuring range
The measuring range of the procedure or instrument shall cover at least the concentrations from 0,1 to 2 times
the limit value for long-term measurements and from 0,5 to 2 times the limit value for short-term
measurements.
5.3.5 Expanded uncertainty
The requirements for expanded uncertainty are given in Table 1.
Table 1 — Expanded uncertainty requirements for measurements
for comparison with limit values and periodic measurements
reference period measuring range relative expanded
uncertainty
short-term (e.g 15 min) 0,5 to 2 times limit value ≤ 50 %
long-term 0,1 to < 0,5 times limit value
≤ 50 %
long-term 0,5 to 2 times limit value
≤ 30 %
NOTE Variation of exposure to chemical agents in the workplace can be significantly greater than indicated by the
uncertainty of a single measurement calculated according to this European Standard. This is due to the temporal and
spatial variability of workplace exposure. See EN 689 for measurement strategy.
5.4 Composite procedures
The performance requirements detailed in 5.1, 5.2 and 5.3 shall be fulfilled for the whole measuring procedure
even if the measuring procedure consists of several distinct steps. In this case each step of the measuring
procedure may be tested individually as an alternative to testing the measuring procedure as a whole.
5.5 Transport and storage
Transport and storage of a sample, if appropriate, shall be carried out in such a way that the physical and
chemical integrity is maintained between sampling and analysis.
5.6 Environmental conditions
The effect of environmental conditions (e.g. temperature, humidity, pressure) on the performance of the
method shall be tested in the laboratory. Performance requirements concerning unambiguity, selectivity,
expanded uncertainty, minimum measuring range and averaging time shall be fulfilled under the conditions
likely to be encountered in the workplace.
NOTE It is not practicable to carry out a comprehensive evaluation of environmental influences in the field and
therefore laboratory tests are specified in this document. However, field tests can provide valuable information on the
performance of measurement methods.
The range of climatic conditions under which the performance requirements of 5.1 to 5.4 are fulfilled, shall be
specified in the measuring procedure.
5.7 Description of measuring procedure
Measuring procedures shall be written in accordance with ISO 78-2. An example for the structure of a method
description is given in Annex B.
The description shall contain all necessary information to carry out the measuring procedure, information
about the attainable expanded uncertainty, measuring range, averaging time, interferences and environmental
or other conditions that can influence the performance of the measuring procedure.
If correction factors are applied, e.g. for known and explainable bias due to environmental influences, these
shall be justified in the measuring procedure and recorded in the validation report.
5.8 Dimension of result
The final result of a measuring procedure shall be expressed in the same units as those of the limit value. This
can be achieved directly or by means of a suitable conversion.
This requirement is not obligatory for screening measurements of the variation of concentration.
5.9 Additional requirements
In addition to the requirements in 5.1 to 5.8, further requirements specified in EN 838, EN 1076, EN 1231,
EN 1232, EN 12919, EN 13205, EN 13890 and EN 45544 (all parts) shall be met for particular types of
measuring procedures and devices, as appropriate.
NOTE ENV 13936 should also be considered, if appropriate
6 Test method
6.1 Estimate the expanded uncertainty of results obtained using the measuring procedure by carrying out
the tests prescribed in the relevant European Standard(s) specific to the type of procedure or device
concerned, as listed in Clause 2. Carry out measurements at the lower and upper ends of the measuring
range specified in Table 1 and at least one intermediate concentration. Prepare at least six replicate samples
for each set of tests and analyse the samples under repeatability conditions.
Calculate the expanded uncertainty, expressed as a percentage, according to the following procedure (see
e.g [2], [4], [5] and ENV 13005).
a) Specify the measurand;
b) identify all possible sources of uncertainty;
c) quantify the random sampling uncertainty ( u ) and non-random sampling uncertainty ( u );

s s
r nr
d) quantify the random analytical uncertainty ( u ) and non-random analytical uncertainty ( u );
a a
r nr
e) calculate the combined standard uncertainty ( u ) according to equation (3);
c
f) calculate the expanded uncertainty (U), using a coverage factor k = 2, according to equation (4).
2 2
u = u + u
(1)
c s a
r r r
2 2
u = u + u
(2)
c s a
nr nr nr
2 2
u = u + u
(3)
c c c
nr r
U= 2× u (4)
c
NOTE 1 Annex C gives information about the different components of sampling uncertainty and analytical uncertainty.
NOTE 2 It is intended to give detailed calculation methods in EN 838, EN 1076, EN 1231, EN 1232, EN 12919,
EN 13205, EN 13890, ENV 13936 and EN 45544 (all parts) when these are revised.
6.2 Carry out further tests, as appropriate, to investigate the influence of interferences and environmental
parameters, e.g. wind speed, wind direction or direction of sampling device.
6.3 For a measuring procedure consisting of several independent steps (preparation of equipment,
sampling, transportation and storage of sample, analysis), each step of the measuring procedure may be
tested individually as an alternative to testing the procedure as a whole. In this case, calculate the relative
expanded uncertainty of the measuring procedure by an appropriate combination of the uncertainties of all the
independent steps.
NOTE For some chemical agents the performance of one or more of the steps might have to be determined by
means other than direct testing with the chemical agent. For details, see the appropriate specific European Standard.
7 Validation report
A validation report shall be prepared for each measuring procedure tested containing at least the test
conditions, the results obtained and the extent to which the measuring procedure complies with the
requirements of this document and other relevant European Standards or International Standards.
Annex A
(informative)
Measurement categories described in EN 689 and involving a
combination of measurement tasks
A.1 Worst case measurements
Screening measurements of variation of concentration in time and/or space (see 4.3) can clearly identify
episodes where higher exposures occur, e.g. high emissions due to certain working activities. Sampling
periods can be selected containing these episodes. This approach is called worst-case sampling.
Subse
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