ISO 16055 pdf download – Tobacco and tobacco products一 Monitor test piece for smoking machine – Requirements and use

ISO 16055 pdf download – Tobacco and tobacco products一 Monitor test piece for smoking machine – Requirements and use.
7 Use
7.1 General
Monitor test pieces are used to monitor the stability of the analytical processes Involved when using a cigarette-smoking machine for routine analyses in accordance with ISO 3308 or ISO 20778. In particular, they are used to assess whether the analytical process related to the machine-smoking oF cigarettes Is in statistical control (see ISO 7870-1).
As monitor test pieces are produced for process-control purposes, the product design is chosen to give smoke yields which arc well suited to these purposes and thus may well not conform to ofFicial declaration restrictions. In this context, it should be understood that the monitor test piece is not to be regarded as a commercial cigarette.
The routine use of monitor test pieces can vary from laboratory to laboratory and between the two commonly used types ofanalytical smoking machine. The general principle is to evaluate the consistency of the values of the essential parameters (such as puff number, carbon monoxide in the vapour phase, total particulate matter and nicotine as well as water in total particulate matter of mainstream smoke and nicotine-free dry particulate matter, if applicable) by using control charts.
Monitor test pieces are not to be used for calibration purposes, and the results obtained with monitor test pieces shall not be used [or correcting or calculating analytical data froni investigation samples.
NOTE 1 The monitor test piece cannot control the process of Vent blocking required by the smoking regime specified in ISO 20778.
The smoke yields are normally based upon the smoking of at least 20 monItor test pieces/cigarettes as described in ISO 4387 or in ISO 20779.
The smoking of 20 cigarettes under ISO 3308 conditions or 10 cigarettes under ISO 20778 conditions gives one average result from a rotary smoking machine, whereas a linear smoking machine gives 4 average results from smokIng 5 cIgarettes in each of 4 channels under ISO 3308 conditions or
3 cigarettes in each of 4 channels under ISO 20778 conditions. This means that the variation in the smoking process shall be determined by different methods for linear and rotary smoking machines. For the rotary machine, the variation may be determined as a “between smoke runs” variation whereas the variation for the linear machine may be determined from the 4 individual results from the 4 channels. In other words, the process variation from the rotary smoking machine is based on “independent” single results while the variation from the linear smoking machine can be based on 4 results from one smoke run but from 4 “independent channels.
This means that different types of control charts shall be used for linear and rotary smoking machines.
The actual choice shall be made according to the actual demands and cannot he specified to fit all needs.
ISO 7870-2 gives advice on, and examples of, the practical use of control charts.
Under the condition that the analytical process Is consistent (stable), It is assumed that all the analytical results obtained between two valid results from the monitor test pieces arc also valid. In contrast. results obtained during a period which begins with a valid check result and ends with a non-valid check result shall be regarded as non-valid until further investigations have indicated their validity. Thus, there is a risk of having to reject these results and having to repeat the analysis. To avoid the loss of large numbers of results, it is important to analyse the monitor test piece at sufficient intervals to reduce this risk. It becomes a balance between analytical capacity and need for confirmation of consistency.
The procedure for the two types of smoking machine will be different but based, of course, upon the same principle: sequential smoking and confirmation of the validity olthe smoking results.
The following procedure can be recommended.
a) For the rotary smoking machine
At the beginning of a series of smoking analyses, a smoking run and an analysis Is performed with the monitor test piece. At practical intervals (for example for each 10 to 15 smoke runs), this procedure should be repeated, ending the day with smoking of the monitor test piece.
h) For the linear smoking machine
At the beginning of a series of smoking analyses. the monitor test j)iece Is smoked on a selection of channels (4 would normally fit into a smoking plan). During the daily smoking, this can be repeated at a practical frequency, with test pieces being smoked on 4 channels for every 2 or 3 smoke runs. To secure the best Information. It Is Important that smoking of the monitor test pIece Is evenly distributed on all channels over a period of time.
7.3 Practical use of control charts
The analysis values from smoking and analysis of monitor test pieces are plotted on the appropriate control charts (see ISO 7870-1 and ISO 7870-2) so that the results for average and for variation can be evaluated.
It Is possible to use control charts both where standard values are given and also where the standard values are not given (see ISO 7870-2:2013, 5.1, 5.2). This means that control charts can be constructed for the individual laboratory without knowledge of the official target values for the test piece, hut the control chart can also be constructed with reference to target values.