2401 10 35: Unmanufactured tobacco; tobacco refuse: tobacco, not stemmed/stripped, light air-cured tobacco

Scope

The scope of the smoking test is to set up a harmonised method to distinguish manufactured tobacco (tobacco ready for smoking without any further processing) of heading 2403 from unmanufactured tobacco of heading 2401. In order to make a distinction between manufactured tobacco of heading 2403 and unmanufactured tobacco of heading 2401, a smoking test shall be performed. The sieving test shall only be performed in the event that it is not be possible to smoke the sample without further (industrial) processing.

Introduction

For the purpose of subheading 2403 19 the expression ‘suitable for smoking’ means that the product could be rolled or filled in the cigarette form and burned with several puffs, or could be filled into the pipe and burned with several puffs).

Principle of the test

Whether it is possible to smoke a tobacco sample is assessed in several ways: by rolling with a cigarette paper to prepare a ‘roll your own’ (RYO) cigarette and filling into the cigarette tube (CTF) or filling the tobacco into a pipe. Pipe and prepared cigarettes are lit and smoked. The ignition and smoking are evaluated.

Field of application

The test is applicable for any tobacco or tobacco products including parts of tobacco products such as cigar filler. The test can be hazardous when the sample is contaminated (affected) by mould.

Equipment

Temperature and humidity control box for sample conditioning (temperature 22 ± 1 °C and humidity 60 ± 3 %)

Cigarette tube filler

Cigarette papers (length 70 mm, width 37 mm)

Cigarette tubes (diameter 7.3 mm, length 85 mm including the filter)

Lighter

Brush for cleaning of cigarette tube filler

Pipe

Pipe tamper

Tools for pipe cleaning

Smoking machine (ISO 3308 compliant)

Sample preparation

The sample is thoroughly mixed and if necessary sub-sampled by coning and quartering. When the sample is dry (water content is less than 8 % by mass), it should be conditioned (temperature 22 ± 1 °C and humidity 60 ± 3 %) for at least 48 hours.

The sample is not allowed to be cut in any way, broken, crushed, ground or otherwise split.

Test procedure

Clean the cigarette tube filler and the pipe.

Pipe:

• An appropriate amount of the sample (at least 5.0 g) is placed into the pipe up to the pipe edge.

• The tobacco in the pipe is lit using a lighter and is gently pressed by pipe tamper. The pipe is puffed at regular intervals of approx. 1 minute.

Cigarettes:

• Cigarette paper: an appropriate amount of the sample is placed on the cigarette paper and paper with the sample is rolled to make a cylinder shape.

• Cigarette tube filler: an appropriate amount of the sample (at least 0.5 g) is placed into the cigarette tube filler and the cigarette is made according to instructions given for the particular filler.

• The prepared cigarettes are lit using the lighter and left to smoulder freely without puffing (to burn excess paper). The cigarette is puffed at regular intervals of approx. 30 to 60 seconds depending on the quality of the tobacco and with a puff duration of approx. 2 seconds.

Test evaluation (typical examples)

If one of the smoking tests is positive, the tobacco can be smoked (subheading 2403 19).

For some samples (especially tobacco refuse) it is possible to roll almost shapeless ‘rolls’. If such ‘rolls’ crumble away before lighting or the ‘tobacco particles’ fall out from the lit ‘rolls’ after the first puff, the result is then noted as follows: ‘it is not possible to roll the cigarette’.

Literature

ISO 3402 Tobacco and tobacco products - Atmosphere for conditioning and testing.

In order to make a distinction between manufactured tobacco of heading 2403 and unmanufactured tobacco of heading 2401, a smoking test shall be performed. The sieving test shall only be performed in the event it shall not be possible to smoke the sample without further (industrial) processing.

Principle of the method

The method is based on determination of mass fractions of the sample remaining on sieves with different mesh size to distinguish between products classified under subheading 2401 20 and products classified under subheading 2401 30.

If 50 % by mass or more of the particles in sample are larger than 3.15 mm (c.f. CORESTA method no 16), the sample is partly or wholly stemmed/stripped tobacco (subheading 2401 20).

If more than 50 % by mass of the particles is smaller than 3.15 mm (in one of all three dimensions), the sample is tobacco refuse (subheading 2401 30).

Applicability

The results can be affected by physicochemical properties of the sample and several other factors:

• Sample specific weight and sample size - affects the time of sieving and is important for assessment of test portion of the sample.

• Sample fragility- affects crumbling of the sample during preparation and sieving.

• Electrostatic and magnetic properties - sample susceptibility to disintegrate or to form clusters.

• Sample hygroscopicity - affects sample weight and particle size.

Equipment

Temperature and humidity control box for sample conditioning (temperature (22 ± 1 °C) and humidity (60 ± 3 %)).

Analytical balances - accuracy min. 0.01 g

Set of circular sieves of specifications according to ISO 3310-1 (metal wire cloth - square aperture), sieve diameter 200 mm, sieve high 50 mm and aperture diameters as follows 0.4 mm; 3.15 mm and 6.3 mm

Ultrasonic bath for cleaning of the sieves

Vibration sieve separator able to produce vibration at 50 Hz and of amplitude 3 mm

Bottom and cover for the set of sieves

Brush for removing the sample particles from sieves

Sample preparation

The sample is thoroughly mixed and if necessary sub-sampled by coning and quartering and divided into two test portions.

The sample is weighed (from 50 g to 150 g) and then conditioned at a temperature of 22 ± 1 °C and a humidity of 60 ± 3 % for at least 48 hours.

After that all work with the sample should be performed in the controlled atmosphere with a temperature of 22 ± 1 °C and a humidity of 60 ± 5 %. Testing temperature and humidity should be measured and included in the test report. Also the atmospheric pressure should be measured and included into the test report when the atmospheric pressure is outside the range 86 kPa – 106 kPa.

Method

Sieves should be clean and undamaged. Every sieve is weighed precisely (0.01 g). Sieves are composed bottom up as follows - bottom (retention container for dust collection), sieve with the smallest aperture diameter, other sieves by ascending aperture diameter and cover.

The conditioned sample is weighed with absolute precision of 0.01 g and evenly spread on the upper sieve which is then closed with the cover.

The set of sieves is placed into the vibration sieve separator and subjected to vibrations at 50 Hz with an amplitude of 3 mm for 5 to 15 minutes (according to the sample weight).

When the sieving is finished the set of sieves is removed from the separator.

Then the cover of the sieve and upper sieve is removed. Dust particles stuck to the sides of the upper sieve are brushed into the sieve and then by five strokes by hand to the sieve these particles are forced to fall through into the sieve underneath (sieve with the smaller aperture diameter).

This dust is removed gradually from all sieves. Each sieve with the sample particles is weighed precisely (0.01 g) as well as the bottom with the dust.

The test is performed in parallel but with another portion of the test sample.

Calculations

The results are calculated as sample mass fraction (residue) remaining on the particular sieve. For each sieve the sample mass fraction Z X is calculated according to the formula:

in % by mass, where

m R is weight (in g) of the particular sieve with the residue, m X is weight (in g) of the particular sieve and m S is the sample weight (in g).

The sieving recovery Y s is calculated according to the formula:

in %, where

m R is weight (in g) of the particular sieve with the residue, m X is weight (in g) of the particular sieve and m S is the sample weight (in g).

Evaluation and expression of results

The sieving recovery should be higher than 99 %. If not, the whole test should be repeated with another sample portion. The sample conditioning is checked according to ISO 3402.

The results are expressed as sample mass fraction (residue on the particular sieves) in % by mass rounded to one decimal. The test report should include also the sieve aperture diameters, time of sieving, vibration amplitude and frequency, sample weight, temperature and humidity of testing atmosphere.

Metrological parameters

Limit of quantification is 5 % by mass.

Repeatability limit is 1.5 % by mass for sample mass fraction between 5 and 20 % by mass. For sample mass fraction higher than 20 % by mass is the repeatability limit r = 0.06 x Zx.

Measurement uncertainty is 2 % by mass for sample mass fraction between 5 and 20 % by mass. For sample mass fraction higher than 20 % by mass is the measurement uncertainty U = 0,1 x Zx.

Literature

CORESTA Recommended Method No 16: Lamina strip particle size determination ISO 2395 Test sieves and test sieving – Vocabulary.

ISO 3310-1 Test sieves - Technical requirements and testing – Part 1: Test sieves of metal wire cloth.

ISO 3402 Tobacco and tobacco products - Atmosphere for conditioning and testing.