SIST-TP ISO/TR 22305:2008

TECHNICAL ISO/TR
REPORT 22305
First edition
2006-06-01
Cigarettes — Measurement of nicotine-
free dry particulate matter, nicotine, water
and carbon monoxide in cigarette
smoke — Analysis of data from
collaborative studies reporting
relationships between repeatability,
reproducibility and tolerances
Cigarettes — Détermination de la matière particulaire anhydre et
exempte de nicotine, de la nicotine, de l'eau et du monoxyde de
carbone dans la fumée de cigarette — Analyse des données provenant
d'études collectives et traitant des relations entre la répétabilité, la
reproductibilité et les tolérances

Reference number
©
ISO 2006
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ii © ISO 2006 – All rights reserved

Contents Page
Foreword. iv
Introduction . v
1 Scope.1
2 Statistical functions for repeatability (r), reproducibility (R) of yield measurements and
compliance tolerances for declared smoke constituent yields .1
2.1 Statistical functions for repeatability (r) and reproducibility (R) .1
2.2 A statistical model for compliance tolerances .2
3 Sources of data.3
3.1 International collaborative studies .3
3.2 UK Department of Health Cigarette Survey data .4
4 Comparison of 2003 CORESTA Collaborative Study data with those previously reported.4
4.1 General.4
4.2 Comparison of repeatability r values from CCS-03 with other collaborative studies.4
4.3 Comparison of reproducibility R values from CCS-03 with other collaborative studies .5
4.3.1 General.5
4.3.2 Relationship between reproducibility R and smoke constituent yield .5
4.4 Comparison of R reproducibility values from collaborative studies with measurement
tolerances estimated from the UK Department of Health Cigarette Survey data .5
5 Review of information relevant to setting a compliance tolerance for carbon monoxide.6
5.1 General.6
5.2 Compliance data for current tolerances.6
5.3 Confidence intervals associated with yield measurements.6
5.4 Statistical models .7
5.5 Prediction of a tolerance for CO from the relative variability in their reproducibility values.8
6 Conclusions .8
7 Recommendations.8
Annex A (informative) Background considerations on the choice of sampling procedures .31
Annex B (informative) The determination of carbon monoxide in cigarette smoke — Problems in
the evaluation of results .33
Annex C (informative) Proposals from the UK Tobacco Manufacturers Association for a
practicable tolerance for verifying cigarette packet declarations of carbon monoxide
(March, 2002).41
Annex D (informative) Analysis of bias measurements from the UK Department of Health
Cigarette Survey .59
Annex E (informative) ASIA COLLABORATIVE STUDY #11 2002/2003 .71
Annex F (informative) 2003 CORESTA Collaborative Study Report CORESTA study for the
estimation of the repeatability and reproducibility of the measurement of nicotine-free
particulate matter, nicotine and CO in smoke using the ISO smoking methods,
September 2003 .86
Bibliography .146

Foreword
ISO (the International Organization for Standardization) is a worldwide federation of national standards bodies
(ISO member bodies). The work of preparing International Standards is normally carried out through ISO
technical committees. Each member body interested in a subject for which a technical committee has been
established has the right to be represented on that committee. International organizations, governmental and
non-governmental, in liaison with ISO, also take part in the work. ISO collaborates closely with the
International Electrotechnical Commission (IEC) on all matters of electrotechnical standardization.
International Standards are drafted in accordance with the rules given in the ISO/IEC Directives, Part 2.
The main task of technical committees is to prepare International Standards. Draft International Standards
adopted by the technical committees are circulated to the member bodies for voting. Publication as an
International Standard requires approval by at least 75 % of the member bodies casting a vote.
In exceptional circumstances, when a technical committee has collected data of a different kind from that
which is normally published as an International Standard (“state of the art”, for example), it may decide by a
simple majority vote of its participating members to publish a Technical Report. A Technical Report is entirely
informative in nature and does not have to be reviewed until the data it provides are considered to be no
longer valid or useful.
Attention is drawn to the possibility that some of the elements of this document may be the subject of patent
rights. ISO shall not be held responsible for identifying any or all such patent rights.
ISO/TR 22305 was prepared by Technical Committee ISO/TC 126, Tobacco and tobacco products.

iv © ISO 2006 – All rights reserved

Introduction
0.1 Summary
The purpose of this Technical Report is to review the smoke yield data provided to Working Group
ISO/TC 126/WG 8 “Confidence intervals for the determination of carbon monoxide” and to use it as the basis
for proposing a tolerance for checks of declared carbon monoxide yields.
There are many laboratories around the world routinely measuring the nicotine-free dry particulate matter
(NFDPM), nicotine and carbon monoxide yield of cigarette brands. They can, in general, be divided into two
types: those run by cigarette manufacturers for quality monitoring and those run or contracted by regulators to
check the yield information provided by manufacturers.
These laboratories need to assess their performance against others to ensure the reliability of their
measurements. Their wide geographical spread limits such assessments on a national basis, so that
international collaborative studies provide the most practical means and generate data sets on a regular basis.
In addition to allowing individual laboratories to rank their measurements relative to others, the studies also
1)
establish confidence intervals (CIs) for the repeatability (r ) of the measurements in a single laboratory and
2)
reproducibility (R ) in different laboratories. The reported r and R values from each study have been used in
isolation but when combined, as in this report, provide a means of assessing if newly reported values are
outside the expected range. The values from the latest 2003 CORESTA study are compared in this way and
found to be within the previously reported range of values but at the lower end. There is no hard evidence,
therefore, that the harmonization work on smoking machines has reduced the variability in CO yield
measurements, but the data have been shown to be as good as the best previously reported. For this reason,
and because it was a large study including all current designs of smoking machine, it provides the most
appropriate data for estimating compliance tolerances.
3)
The measurement CIs represented by r and R provide a starting point for estimating the tolerances
20 20
relevant to compliance checks on the yield information provided by manufacturers. They need to be combined
4)
with additional information on testing and reporting as well as the inherent variability in the product
associated with routine cigarette manufacturing. The statistical model given in this report is designed to
incorporate all the relevant information to estimate compliance tolerances. The model is based upon the within
and between laboratory standard deviations for tests of 100 cigarettes, together with additional terms to
account for rounding the declared values and to include the product variability. A weakness in the model
approach stems from the lack of data for estimating the terms relating to product variability, the only source of
data being the UK Department of Health Survey, which is not specifically designed to provide such data. For
this reason the model has been used in this report without including the product terms and the calculated
5)
tolerance values [R ] compared with those from an alternative indirect prediction. Obviously, the
100+rndg
R values are lower than the true compliance tolerance since they do not include the product terms.
00+rndg
The simplest indirect way of predicting a CO tolerance is from the measurement variability relative to NFDPM,
for which an accepted tolerance exists. The ratio of the R values calculated from the CORESTA 2003
100+rndg
Study data was used for this purpose.

1) Based on tests of 20 cigarettes.
2) Based on tests of 20 cigarettes.
3) ISO 8243 has always included tolerances for NFDPM and nicotine but an interim CO tolerance was added in 2003
whilst ISO/TC 126/WG 8 considered a permanent value.
4) See ISO 4387 and ISO 8243.
5) Based on tests of 100 cigarettes with allowance for rounding the declared value.
6)
ISO 8243 provides procedures, and tolerances , for sampling both ‘over a period of time’, which is
recommended, and ‘at one point in time’. Tolerances derived from both the statistical model and ratio methods
for ‘over a period of time’ sampling are summarized below.
Parameter evaluated Carbon monoxide tolerance
20 % with a minimum of 1,5 mg
R
or
100+rndg
25 % with a minimum of 1 mg
R ratio
100+rndg
22 % with a minimum of 1,5 mg
(CO/NFDPM)
It is recommended that the compliance tolerance for CO be set at 20 % for ‘over a period of time’ sampling,
and 25 % for ‘at one point in time’ sampling, with a minimum value of 1,5 mg. This recommendation implies a
corresponding amendment of ISO 8243.
It is further recommended that the tolerances and minimum values are reviewed when compliance rates are
established from regulatory checks. It is possible that such data may only become available in the UK and
may take two or three years to assemble.
0.2 General Information
Methods of measurement specified in ISO Standards require estimates of repeatability (r) and reproducibility
[1]
(R). These are normally derived from a collaborative study conforming to the guidelines in ISO 5725-1 and
[2]
ISO 5725-2 involving as many laboratories as possible.
There is a particular problem in obtaining estimates when the measurement results in the destruction of the
product sample, for example, cigarett
...