Cc. Relative Ignition Propensities of the Conventional and Banded Cigarettes

Having established the properties of the substrates to be used in the tests of the conventional and
banded cigarettes, the next step in the analysis was to compare these two cigarettes to see if they
differ in relative ignition propensity. Tables 5 and 6 show the test results.

Table 5. Ignition Propensities of Conventional and Banded Cigarettes Measured
Using the Mock-up Ignition Method (number of ignitions/number of trials)

2000
Cigarette Duck 10 | Duck 6 Duck4 | Ivory Cot.
Conventional 32/32 32/32 1/32 32/32
Banded 12/32 | 16/32 1/32 _19/32

Table 6. Ignition Strengths of Conventional and Banded Cigarettes Measured
Using the Cigarette Extinction Method (number of full-length burns/number of trials)

2000
Cigarette 3 Layers | 10 Layers | 15 Layers
Conventional 24/24 24/24 24/24
Banded 9/24 | 2/24 3/24 |

The comparison using the Mock-up Ignition Test is shown in Figure 3 and Table 7. The 95 %
confidence intervals for the ignition propensities of the two cigarettes do not overlap for three of
the substrates, indicating that the conventional and banded cigarettes do differ significantly in
terms of relative ignition propensity on those substrates. The conventional cigarette has a high
ignition propensity on the duck #6, duck #10 and ivory cotton substrates. The banded cigarette
has a lower ignition propensity across these three substrates. On the most difficult substrate to
ignite, duck #4, the confidence intervals do overlap substantially. This indicates that both the
conventional and banded cigarettes have similarly low relative ignition propensities on this
substrate. The 95 % confidence intervals for the difference in relative ignition propensity confirm
these results in that each of the confidence intervals for the duck #10, duck #6 and ivory
substrates has an upper confidence bound lying below zero. This indicates that all plausible
values for the relative ignition propensity of the banded cigarettes are less than the plausible
values of the relative ignition propensity of the conventional cigarettes. For duck #4 the
confidence interval for the difference in relative ignition propensities just includes the value zero,
indicating that the two cigarettes have a small range of plausible values for their ignition
propensities in common.

The relative ignition propensities measured for the ivory cotton fabric substrate are not
distinguishable from the values measured for the substrates containing cotton ducks #6 and #10.
While the areal density of the ivory cotton fabric is in the range that industry data indicated could
show reversals (relative to the cotton duck substrates) in the ranking of cigarette ignition
propensity, no such reversal was found for this fabric.




The randomized sequence of the Mock-up Ignition Test Method testing was:

Cycle Test Point
1 4/3 /1/7;)8 [16 [2 ]5
2 8121/5353 |6 1441 |7
3 7{8|4 3/6 {1 |2 [5
4 § {4/1758 |2]1|3 [6
_§ |7 1412/1 Je [s [8 3
6 [2 [41117755 [6 [8 33
7 li fate [3s i7 fale ys
[8 114 6/3 1512.7 18
where the test points were:
Test |
Point Cigarette Fabric
|_|. Conventional Duck #4
2 Conventional Duck #6
3 Conventional Duck #10_
4 Conventional
3 Banded #4
6 Banded |, “Duck #6
7 Banded Duck #10 |
3 | Banded | dvory

G. Statistical Evaluation Methodology

The data obtained from these experiments were analyzed to determine whether the ignition
propensities of the experimental cigarettes had changed during storage, the similarity of the new
mock-ups to those used in 1993, and the degree of difference between the conventional cigarettes
and those with the banded paper. The statistical analysis consisted of two steps:

1. selection of an appropriate set of statistical methods for estimating and comparing the
measurements of relative ignition propensity of different types of cigarettes under
different conditions as laid out in the series of experiments; and

2. analysis of the data for each set of test conditions individually, along with the
comparisons of ignition propensities obtained under different test conditions.

The analysis of the data obtained under each individual test condition is relatively easy to
interpret because it is given directly in terms of ignition propensity. Having this information on
hand aids understanding of the somewhat less easily interpreted comparisons of different test
conditions, which are differences of ignition propensities. The individual results also provide
additional background information that is lost in the comparisons. The comparisons of the
various test conditions, however, directly answer the main questions of interest.


APPENDIX A. Request Letter of May 15, 2000, from the Federal Trade Commission ic
the National Institute of Standards and Technology

| SUTHDY STATS Co APR

FEDERAL TRADE COMMISSION
WASHISITON. Bx 280

May 135, 2900

Dr, Jack E Snell

Director

Building and Fire Research Laboratory

Mail Stop 8600

Naziomal Institute of Standards and Technology
10 Burgas Drive

Gaithersburg, MD 30899-6500,

Dear Dr. Snett:

It is my understanding that the Nationa! insticure of Standards ani Technology (°NIST)
is able to conduct tests to determine the relative likelihood of igniven of different types of
cigarestes, and would be willing 16 conduct such legis upon request by the Federal Trade
‘Comrnission. Philip Morrix, inc. recently announced publicly its plans to test market 2 cigarette
made with a slower burning paper that would reduce the risk that a dropped or discarded cigaren:
will start a fire! [t would greatly assist the Commission in its responsibilities over tobacco
products if NIST would conducs tests 10 determine whether snd to what extent this cigarette: dacs
reduce the risk of ignition, Thus] am requesting Gial NIST perform such tests as needed 10
evaluate dus cigarette.

Thank you very much for your assistance, Lf yoo have amy questions, please cal
Rosemary Rosso ar (202) 326.2174.

Suncerely, .
peli
rector
Bureau of Consumer Protection
cc Dr, Richard G, Gann
' See "Philip Mortis Plana Siow Bum Paper.” www pvtimes com/gponisne TAP

‘Sdow-Burn hon) (fam. 11, 2000).


ABSTRACT

The Federal Trade Commission (FTC) staff requested that the National Institute of Standards and
Technology (NIST) conduct tests to determine whether a test market cigarette made with a
slower burning paper would reduce the risk that such a cigarette, if dropped or discarded, would
start a fire. While NIST does not routinely perform product tests, it agreed to do so in this case,
recognizing the important role of the FTC in assuring the public of the veracity of product claims
and the high potential for less fire-prone cigarettes to reduce fire deaths and injuries. NIST staff
purchased conventional and modified cigarettes from the test market and measured the relative
ignition propensities of the two cigarette types using the Mock-up Ignition Test Method and the
Cigarette Extinction Test Method, both developed under the Fire Safe Cigarette Act of 1990
Analysis of the test data shows that the modified cigarette has a lower relative ignition
propensity than the conventional cigarette

Keywords: fire, cigarette, ignition

THE RESEARCH ON REDUCED IGNITION PROPENSITY CIGARETTES
CONDUCTED BY NIST SINCE 1984 WAS DONE IN THE INTEREST OF SAVING
LIVES AND PROPERTY FROM CIGARETTE-INDUCED FIRES. INNO WAY DOES
IT LESSEN OR NEGATE THE HEALTH HAZARDS AND ADDICTIVE NATURE OF
SMOKING AS DETERMINED BY THE SURGEON GENERAL OR SUGGEST THAT
NIST AND THE DEPARTMENT OF COMMERCE CONDONE SMOKING.

Certain commercial materials and products are identified in this report to specify the procedures
adequately. Such identification is not intended to imply recommendation or endorsement by

NIST.


Figure D-1. Photograph of Test Chamber
and Filter Paper Holder

Figure D-2. Close-up of Filter Paper Holder
and Metal Rim

29


Figure 3. 95 % Confidence Intervals for the Relative Ignition Strengths (RIS) of
Conventional and Banded Cigarettes on Different Mock-up Test Substrates

Duck 10

Duck 4

Banded
Cigarette Type

se| |
Bs
Be
ge
Bs
zs
Z
e
‘Conventional
bs
Be
5°
Be
os
s
8
2
2
Conventional

Banded
Cigarette Type

Relat
00 92

Duck 6

Conventional Banded

Cigarette Type

Wvory Cotto:

10

v6 08

Relate Igeiton Stengt
02 04

00

I

Conventional Banded

Cigarette Type

Table 7. 95 % Confidence Intervals for the Difference in Relative Ignition Strengths
of Conventional and Banded Cigarettes on Different Mock-up Test Substrates

(RUSpanded— RUS conventional)

RUSpandea— RUS conventional

Duck 10

Duck 6

Duck 4

Ivory Cot. _

-0.77 to -0.41

-0.66 to -0.31

-0.31 to 0.00

-0.57 to -0.23

The results of the comparison of the standard and banded cigarettes using the Extinction Test are
shown in Figure 4 and Table 8. The interpretation of the plots in Figure 4 and the confidence
intervals in Table 8 is similar to those for the Mock-up Ignition Test. In the case of the
Extinction Test, however, the modified cigarette showed a significantly lower relative ignition
propensity than the conventional cigarette on ai/ substrates.


Calibration and Standardization

Calibrations of equipment were carried out at regular intervals and at any time when
equipment or test conditions indicate that evaluation and re-calibration were necessary.

The ignition test chambers were checked before use to insure that the front door seals
properly and that air movement in the test area does not introduce transient air movement
in the test chambers. Door seals were checked visually to ensure that they closed flush
against the chamber’s side wall and the latching device secured the door tightly. All
construction seams were inspected to ensure they were airtight, with no cracks visible on
any surface of the test chamber.

The stability of the air inside each test chamber was determined daily by placing a Jit
cigarette in the test position on one or more layers of filter paper, then closing the
chamber door. Smoke being emitted by the cigarette rose vertically and showed no
turbulence within 150 mm above the lit end of the cigarette.

The humidity and temperature sensors used to record environmental conditions in the
conditioning room or the chamber and test room were checked for accuracy daily.

The air draw apparatus used for igniting cigarettes was calibrated at the beginning and
end of this project.

Test Specimens and Standard Substrate Assemblies

Cigarette test specimens were protected from physical or environmental damage while in
handling and storage. Clean plastic gloves were worn at all times to minimize
contamination of the cigarette test specimens and filter paper substrates, which are
sensitive to contamination. If the specimens were to be stored for more than one week.
they were placed in a freezer reserved for the sole protection of cigarette specimens.

Prior to testing, cigarette test specimens were marked on their paper seam 5 mm and
15 mm from the tobacco end with a #2 graphite pencil. These marks are used to establish
a uniform burn and the start of the coal respectively.

The substrate materials were as follows:
The open-cell, non-fire-retarded flexible polyurethane foam had been cut into blocks

200 mm + 5 mm square and 50 mm + 2 mm thick. The foam density was 32 kg/m’ +
3 kg/m? and the air permeability was 1.9 x 10° m°/s + 0.1 x 10° m/s.


ignition propensities. The five numbered cigarettes are those experimental cigarettes used in the
ILE of the two test methods.

Table 9. Percent Ignitions or Full Length Burns on Test Method Substrates [Prior
data from reference 9]

SUBSTRATE — | 3layers | Duck #10 | 10 layers | Duck #6 | 15 layers | Duck #4
CIGARETTE ¥ _—_
1993 Commercial 100 100 100 100 100 100
B 100 100 | 100 9 od) 3
503 100 100 100 100 100 “3
Conventional 100 100 100 100 100 19
501 100 100 100 100 100 1]
D 100 100 o4 73 88 46
E 100 100 100 96 94 0
531 99 98 7 94 95 88 0
A 100 100 94 2 38 4
F 100 100 “79 | 19 0
529 S7 30 8 2
Banded 39 37 fp & a “50 ~| “a2

530 6 3 6 0 0

Cigarettes 531 and 529 differ in the air permeability of the wrapping paper. The same is true of
the conventional and banded cigarettes, although the permeability difference is only in the
banded regions. There is a similarity in performance between the 531 and the conventional
cigarette, with nominally 100 % failures on five of the six substrates. The 529 and banded
cigarette show similar and significant improvements on those five substrates, as well as large
differences from the 1993 best-selling cigarettes. For the #4 cotton duck substrate, the most
difficult to ignite, the conventional cigarette caused relatively few ignitions, leaving no room for
the banded version to show improvement.

VI. CONCLUSION

As requested by the Federal Trade Commission staff, NIST has measured the ignition propensity
of a test market cigarette made with slower burning paper relative to the performance of the
unmodified product. Analysis of the test data shows that the banded cigarette has a lower
relative ignition propensity than its conventional counterpart.


APPENDIX E. MEASUREMENT OF CIGARETTE PAPER BANDS
(Work performed by Jiann C. Yang, NIST)

Two samples of the banded paper were obtained by removing the filters and tobacco from
two cigarettes. The curled papers were straightened by placing them between two glass
slides overnight. The papers were placed in a 35 mm film and negative holder and
digitized using a slide scanner (Microtek ScanMaker 35t). The width of the paper band
and the distance between the two adjacent bands were obtained by enhancing (histogram
stretching) and analyzing the digital images using image analysis software
(SigmaScanPro 4.0). Spatial calibration was obtained by scanning a Leica 2 mm
micrometer mounted on a glass slide. The uncertainty associated with the calibration
micrometer is +1 pixel (0.02 mm). For each paper sample, 10 random measurements
were made along the width of the band and the distance between the two bands.

Table E-1. Measurement of Band Width and Band Separation

Cigarette paper 1 ; Cigarette paper 2
Width Width Separation | Separation Width Width Separation | Separation
(pixels) (mm) (pixels) (mm) (pixels) (mm) (pixels) (mm)
272 5.79 1016 21.62 309. 6.58 936 | 19.92
264 5.62 1024 21.79 309 6.58 938. | 19-96
262 5.58 1000 21.28 308 | 6.55 934 19.87
272 5.79 1016 21.62 | 3 6.62 936 | ‘19.92
270 5.75 i 1016 21.62 308 6.55 936 19.92
266. 5.66 1012 21,53 [310 6.60 942 20.04
272 5.79 1012 21.53 308 6.55 940 | 20.00
273 5.81 1008 2145 | 309 6.58 932
262 5.58 1020 21.70 | 310 6.60 936, Lo
266 5.66 1004 2136310 6.60 38 '
5.70 £0.09 6.58 + 0.03 19.93 £0.06
mean + std mean + std LL std

Calibration factor: 2 mm = 47 pixels



Figure 1. 95% Confidence Intervals for the Relative Ignition Strengths (RIS) for
Cigarettes 529 and 531 over Time

Cigarette 529, 3 Layers

10

00 02 04 06 08

Year

Cigarette 531, 10 Layers

1.0

H
6
§
5
g
é

2
6
é
2

+

1993,

2000
Year

08 10

Relative ignition Strength

00 02 04 96

10

Relative Ignition Strength
06 Os

02 04

90

Cigarette 529, 10 Layers

Year

2000

B. Similarity of New Mock-up Substrates to 1993 ILE Substrates

Table 3 shows the current data on the two experimental cigarettes with the current fabric/foam
substrates, compared with the corresponding data from the NIST participation in the 1993 ILE of
the Mock-up Ignition Method.

Table 3. Similarity of New Mock-up Substrates to [LE Substrates
(number of ignitions/number of trials)

1993 2000
Cigarette Duck 10 Duck 6 Duck 4 Duck 10 Duck 6 Duck 4
529 18/48 6/48 0/48 4/24 0/24 _
531 47/48 48/48 0/48 23/24 24

Since the Mock-up Ignition Method test procedure and the operational variables were the same
as for the 1993 testing and since the relative ignition propensities of the cigarettes had been
shown not to have changed significantly, any differences between the 1993 and 2000 test data
can be attributed to changes in the susceptibility of the substrates to cigarette ignition. Figure 2



Ii.

MATERIALS AND METHODOLOGY

A. Cigarettes

1.

Experimental Cigarettes. A supply of the experimental cigarettes provided by the

cigarette industry during the course of the Fire Safe Cigarette Act of 1990 had been

stored in freezers at approximately 0 °C since that time. Two were selected for this

project:?

= Cigarette 529 was 100 mm in length and 25 mm in circumference, manufactured of
expanded, flue-cured tobacco, and wrapped in paper of low air permeability.

= Cigarette 531 was also 100 mm in length and 25 mm in circumference and
manufactured of expanded, flue-cured tobacco. The tobacco was wrapped with paper
of conventional air permeability.

Commercial Cigarettes. Cartons of the test cigarettes with the banded paper were
purchased in Denver, CO (one of the test market cities) in May 2000. Cartons of
conventional cigarettes of the same brand were purchased at a different location on the
same date in the same city. The cigarettes'' were characterized as follows:

Weight: Both the conventional and modified cigarettes weighed 1.030 g each.

Band structure: The band dimensions were determined to provide an approximate
characterization for identification of these cigarettes. The bands were approximately 6
mm in width and were spaced by about 20 mm. Details are provided m Appendix E.
Neither the porosity nor the air permeability of the paper or the bands was measured

No further chemical or physical measurements were performed on either set of cigarettes.
Thus, it is not known whether there were any additional differences between the
conventional and modified packings.

Substrate Materials

Fabrics. The #4, #6, and #10 cotton ducks used in this study were taken from stock
remaining from the 1993 ILE conducted by NIST.” Since 1993, the ducks have been
stored at NIST in a conditioning room, nominally at a relative humidity of 50 + 5 % anda
temperature of 21 °C +3 °C.

Cigarette industry studies'?” had shown that some fabrics produced reversals in the
ordering of cigarette ignition performance. These reversals were said to be more likely
with fabric areal densities in the range 0.30 kg/m? to 0.44 kg/m? (9 oz/yd? to 13 oz/yd")

"' Both types of cigarettes were Merit Ultra Light 100s. Certain commercial materials and products are identified in

this report to specify the procedures adequately. Such identification is not intended to imply recommendation or
endorsement by the National Institute of Standards and Technology.

"2 Spears, A.W., Rhyne, A.L., and Norman, V., “Factors for Consideration in a Test for Cigarette Ignition Propensity
on Soft Furnishings,” J. Fire Sciences 13, 59-83 (1995)

'? Lewis, L.S., Morton, M.J., Norman, V., Ihrig, A.M., and Rhyne, A.L., “The Effects of Upholstery Fabric
Properties on Fabric Ignitabilities by Smoldering Cigarettes. II..” J. Fire Sciences 13, 445-471 (1995).


i.

The filter paper substrates consisted of 150 mm diameter circles of Whatman #2 filter
paper. They were formed by placing multiple layers of filter paper into the holder
assembly, then placing the metal rim on top to ensure good contact between the layers.

Conditioning

The cigarettes were conditioned at a relative humidity of 55 % + 5 % and a temperature
of 23 °C = 3 °C for at least 24 hours prior to ignition testing. The cigarettes were stored
vertically, filter end up, in a clean 250 mL polyethylene or glass beaker, with a maximum
of 20 cigarettes per beaker to enable free air access to the specimens.

Filter papers were conditioned at a relative humidity of 55 %% + 5 % and a temperature of
23 °C + 3 °C for at least 24 hours prior to ignition testing. Individual papers were
supported side-be-side in racks that held each piece vertically on edge and maintained air
spaces between the individual sheets. Small fans located ca. 100 mm above the tops of
the sheets provided gentle downward air circulation.

Procedure

Tur on the exhaust system designated for removal of test combustion products 30 min
prior to beginning testing.

Ensure that the filter paper holder is in the test chamber at the geometric center of its
bottom. Cover the chimney on the test chamber.

Select the number of layers of filter paper for the scheduled tests. Immediately before
testing, place the proper number of filter papers on the filter paper holder and place the
metal test rim on top. Do not use filter papers that will not lay flat.

Place the cigarette holder on the center of the filter papers.

Without delay, remove a cigarette from the conditioned space. Insert the unmarked end
of the cigarette into the cigarette ignition system and hold it in a horizontal position.
Tum on the air draw, verifying that the air flow is 15 mL/s to 20 mL/s. Hold the ignition
flame to the marked end of the cigarette for as long as is necessary to achieve uniform
ignition without passing the 5 mm mark.

Holding the cigarette vertically, coal end up and under a 600 mL beaker, transport the
cigarette to the test chamber.

Place the lit cigarette, still vertical, in the cigarette holder.
Simultaneously close the door and remove the chimney cover.

If the cigarette should self-extinguish while in the cigarette holder, terminate the test and
record the results as a self-extinguishment and note that this occurred in the holder.


Test Report
Report the following information for each test:

Name of person performing the test

The temperature and relative humidity in the laboratory
Date of each test

Cigarette identification

The fabric type and sample number

The sample number for the foam block and plastic film
The outcome of the test

For each trial, report the percentage of tests in which the cigarettes ignited the substrates.

Figure C-1. Photograph of Test
Chamber and Cigarette on Mock-up

Assembly
Figure C-2. Close-up of Cigarette on

Mock-up Assembly with Square Frame in
Place



L INTRODUCTION

Cigarettes dropped onto upholstered furniture and beds continue to be the leading single cause of
fire deaths in the United States. The Consumer Product Safety Commission (CPSC) estimated
that in 1997, cigarette-ignited fires resulted in about 880 deaths, 2120 injuries, and a direct
property loss of $335 million.' A 1993 report had estimated the total cost to our society of $5

billion.“

Over the past three decades, most of the fire safety standards effort has been directed at
improving the resistance of the fuel (mattresses’, commercial furniture”. and residential
upholstered furniture®) to the ignition source. These standards have contributed to reducing these
losses significantly.° However, the median life of these furnishings has been estimated at 12
years for mattresses and 15 years for upholstered furniture’, so most of the old items have been
replaced, and little additional decrease in fire losses is expected from these standards.

There have also been efforts to reduce the potency of the ignition source, the cigarette, by
reducing its propensity to ignite soft furnishings. Research under two Federal Acts, each of
three-year duration, has generated substantial technology in this direction:

The Cigarette Safety Act of 1984 (P.L. 98-567). Research showed that there were
three modifications of the cigarette that would reduce its likelihood of starting a fire:
reduced tobacco packing density, smaller cigarette circumference, and less porous paper.”
A shorter tobacco column length, the absence of a filter tip, and the absence of a burn
additive in the paper had effects in limited cases.

In addition, five patented modifications were tested. All five showed significantly
reduced ignition propensity relative to identical cigarettes without the patented feature *

' Mah, J., Smith, L., and Ault, K., “1997 Residential fire Loss Estimates,” U.S
Commission, 2000.

? Ray, D.R., Zamula, W.W., Miller, T.R., Cohen, M.A., Douglass, J.B., Galbraith, M.S., Lestine, D.C., Nelkin, V.S.
Pindus, N.M., Smith-Regojo, P., “Societal Costs of Cigarette Fires,” Report No. 6, Technical Advisory Group. Fire
Safe Cigarette Act of 1990, U.S. Consumer Product Safery Commission, August 1993.

> 16 CFR 1632.

* Based on “E 1352 Standard Test Method for Cigarette Ignition Resistance of Mock-up Upholstered Furniture
Assemblies,” Annual Book of ASTM Standards, Vol. 4.07, ASTM, Philadelphia, PA.

* Based on “E 1353 Standard Test Method for Cigarette Ignition Resistance of Components of Upholstered
Fumiture,” Annual Book of ASTM Standards, Vol. 4.07, ASTM, Philadelphia, PA.

° Comparison of data in the CPSC National Fire Loss Estimates for 1984 and 1997 shows a 40% reduction in deaths
and injuries.

” Private communication, M. Neily, U.S. Consumer Product Safety Commission, 2000.

* Gann, R.G., Harris, Jr., R.H., Krasny, J.F., Levine, R.S., Mitler, H.E., and Ohlemiller. TJ., The Effect of Cigarette
Characteristics on the Ignition of Soft Furnishings, Report No. 3, Technical Study Group on Cigarette and Little
Cigar Fire Safety, Cigarette Safety Act of 1984, and NBS Technical Note 1241, J.S. National Bureau of Standards,
Gaithersburg, MD, 1987.

sumer Product Satety


This page intentionally left blank.


shows the 95 % confidence intervals for each substrate at each pair of times. Again, the intervals
overlap substantially, indicating that there is no evidence of difference in the ignition
susceptibility of the corresponding substrates. This is confirmed by all the approximate 95 %
confidence intervals in Table 4 containing the value zero.

Figure 2. 95 % Confidence Intervals for the Relative Ignition Strengths (RIS) of
Cigarettes 529 and 531 on Different Mock-up Test Substrates over Time

Cigarette 529, Duck 10 Cigarette 529, Duck 6
e @ pee
2s
Be
35 | 23
Ba ao
as : 38
S a
1993, 2000 4993, 2n00
veo ve
Cigarette 531, Duck 6 Cigarette 531, Duck 4
ba T 7. ee |
ee
Be
2° :
ze 2¢
3 aq .
1988 2000 1983 000

Table 4. 95 % Confidence Intervals for the Relative Ignition Strengths (RIS) of
Cigarettes 529 and 531 on Different Mock-up Test Substrates (RIS2000- RISj993)

RIS2o90 - RISi995,
Cigarette Duck 10 Duck 6 Duck 4
529 -0.38 to 0.02 -0.23 to 0.02
531 _{. -0.20 to 0.02 -0.06to0.14 |



On May 15, 2000, soon after the test marketing of the modified cigarettes began, Joan Z.
Bernstein, Director of the Federal Trade Commission (FTC) Bureau of Consumer Protection,
sent a letter to Dr. Jack E. Snell, Director of the National Institute of Standards and Technology
(NIST) Building and Fire Research Laboratory (BFRL), requesting that NIST “conduct tests to
determine whether and to what extent this cigarette does reduce the risk of ignition.” On May
19, 2000, Dr. Snell replied “While NIST does not routinely perform product tests, we recognize
the important role of the Federal Trade Commission in assuring the public of the veracity of
product claims and the high potential for less fire-prone cigarettes to reduce fire deaths and
injuries. We thus agree to measure the ignition propensity of these test cigarettes relative to the
performance of the unmodified product. Note that this is not an absolute measure of ignition
probability in real circumstances, but is a strong indicator as to whether a reduction in cigarette-
initiated fires might be expected.” Copies of the two letters appear as Appendices A and B to
this report.

This report presents the results of the NIST testing of the ignition performance of the
conventional cigarettes and the modified (banded) product. While the only publicly stated
difference between the two types was the banding of the wrapping paper, NIST performed no
tests to ascertain that there were not additional differences

I. WORK PLAN

Three sets of measurements were carried out. These are described in reverse order of their
execution to clarify the rationale for each component of the project.

A. Tests to determine the extent of difference in ignition propensity between the
conventional and modified cigarettes. Both the Mock-up Ignition Method and the
Cigarette Extinction Method were used. The apparatus and procedures, given in
Appendices C and D, respectively, are the same as those used in the 1993 study.” In
each case, a sufficient number of repetitions were performed to ensure that we could
see real changes, yet few enough to produce results in a timely manner.

B. Tests to help estimate the impact of the modified cigarettes. Doing this required
placing the results in the context of the extensive testing on experimental and
commercial cigarettes performed under the two Acts.

1. This task was to “calibrate” the mock-up substrates relative to those used in the
1993 testing. This involved using two experimental cigarettes of different
ignition strengths (types 529 and 531 from the 1990 Act”) and determining the
extent to which the new substrates performed as their 1993 counterparts did.

2. This “calibration” required knowing that the extent to which the two experimenta!
cigarette types showed the same ignition strength as in 1993. (They had been
stored in freezers since then.) For this, the two were checked against each of two
filter paper substrates for which data had been taken in 1993. This filter paper is
invariant over the years.


APPENDIX B. Reply Letter of May 19, 2000, from the National Institute of Standards
and Technology to the Federal Trade Commission.

on |
hs ~ UNITED STATES DEPARTMENT OF COMMERCE
z | Mmaonel Inetieute of Btanderds and Technology
Se Goiterstury. Marganc 20895.

May 19, 2000

Me. Joan Z. Bernsteia

Director, Bureau of Consumer Protection
Federal Trade Commission

Washington, D.C. 20580

Dear Ms. Bernstein

Thank you for your letter requesting that the Natvanal Institute of Standards and Tectmology
(NIST) use its expertise to determine the relative likelibood of ignition of so furnishings by the
new cigarettes of Philip Mosris, Inc. While NEST docs not rowtinely perform product teats, we
recognize the important role af the Federal Trade Commission in assuring the public of the
veracity of product claims and the high potential for less fire-prone cigarettes to reduce fre deaths
and injuries. We thus egree to measure the igratboe propensity of these test cigarettes relative to
she performance of the unmodified product. Note that this is nat an absolute measure of ignition
prodabélity in real ciroumpiances, but ix a strong indicator as to whether s reduction in cigarette-
initiated Gres might be expected.

We should be able to complete our work and tansmut a report to you within 5 months. After no
more then @ short delay, we would expect the report to become public.

Dr Richard Gann [phone: (301) 975-6866; recanndginisi soi) will be our point of contact te
work with Ms, Rosso on this matter.

Sincerely, +

ibWintg and Fire Research Laboratory
ce: Richard Gann

Raymond Kammer

Michael Rubin

Matthew Heyman
Rosemmy Rosso

NItsr

19


NIST Technical Note 1436

Relative Ignition Propensity of
Test Market Cigarettes

Richard G. Gann, Kenneth D. Steckler, Schuyler Ruitberg, William F. Guthrie and Mark S.
Levenson

NisT

National institute of Standards and Technology
Technology Administration, U.S. Department of Commerce



Cc. Verification of the Ignition Propensities of Experimental Cigarettes

A series of tests was performed to determine whether the ignition propensities of cigarettes 529
and 531 had remained unchanged since 1993. For the sake of time, each cigarette was tested on
only two of the original filter paper substrates: 3 and 10 layers for cigarette 529, 10 and 15 layers
for cigarette 531. Cigarettes from four packs were randomized and an identification number was
printed in pencil on the filter tip of each cigarette. Six test sets were performed for each test
point, resulting in 24 repetitions per test point. The results were to be compared with the NIST
results from the 1993 interlaboratory evaluation (ILE) of the two test methods.

The randomized sequence of tests was:

Cycle Test Point
1 Lt 2 4 13
2 1 3 2 4.
3 3 1 4 2 |
a pa prs 2
3 1 2 4)
oo |
6 1 2 3 45
where the test points were:
Test ] i Oe 7 ~
Point | Cigarette | Test Type | Layers
1 529 Extinction 3
2 329 Extinction 10
3 531 Extinction 10
4). S31 | Extinction 1S

E. Evaluation of the Susceptibility of the Foam/Fabric Film Substrates

A second series of tests was performed to determine the degree of similarity of the new
substrates (consisting of long-stored fabrics and film and a different batch of foam) to those in
the 1993 ILE. Two substrates were tested using the two experimental cigarettes: the #10 and # 6
cotton duck substrates were tested with cigarette 529, the #6 and #4 cotton duck substrates were
tested with cigarette 531. In addition to the randomization of the cigarettes, the pieces of foam,
fabric and film were also randomized and labeled. Six test sets were performed for each test
point, resulting in 24 repetitions per test point. The results were again to be compared with the
NIST results from the 1993 ILE. The randomized sequence of tests was:

Test Point
2 4 i 3
1 2 4 3
2 i 4 3
i4 2 1 3
4 3 2 1 |
6 2 3 4 l



cC.

We designed the current study to include one or more such fabrics to determine whether
the relative performance of the conventional and banded cigarettes might reverse.
Canvassing the local fabric/upholstery stores, we purchased 19 100 % cotton fabrics in
this weight range. Each showed smoldering afterglow when ignited with a small flame
from a propane torch and then blown out. However, only one of these then supported
smoldering ignition from a cigarette. This material had an ivory color and an areal
density of 0.36 kg/m’ (10.5 oz/yd’). We purchased a continuous length from a single
bolt of this fabric for use in this study.

Foam. Non-fire-retarded flexible polyurethane foam has become a specialty item not
routinely stocked by vendors. Owing to a lack of inventory, the manufacturer of the non:
fire-retarded polyurethane flexible foam used in the 1993 standard mock-up tests (no
2048 from Vitafoam Inc., High Point, NC) could not supply material for the present study
within the available time frame. We leamed that Philip Morris U.S.A. had on hand a
supply of the 200 mm x 200 mm x 50 mm foam blocks. NIST purchased from Philip
Morris 1000 pieces of that non-fire-retarded foam for the present study. An essential
component of the test plan (Section I[I.E) is a determination of whether the substrates
using this new foam perform the same as the 1993 substrates. A successful companson
would both enable comparison of the new data with the 1993 results and quell any
concerns about the source of the new foam blocks. The test results reported in Section
IV.B. of this report show there was no difference in ignitability between the substrates
made with the new foam and the corresponding substrates in the 1993 study.

Film. The polyethylene film used with the #4 cotton duck substrates in this study was
taken from stock left over from the 1993 ILE.” Since 1993, the roll of film has been
stored at NIST in its original cardboard shipping box.

Filter Paper. The paper used was 150 mm diameter Whatman #2 filter paper that was

taken from stock remaining from the 1993 ILE.” Since 1993, the paper has been stored at
NIST in the original sealed boxes containing 100 papers each.

General Test Procedure

Four test chambers were employed in executing each method. A test point is defined as an
evaluation of a specific cigarette/substrate/procedure combination. Each test point was evaluated
simultaneously in the four test chambers. These four simultaneous test point determinations are
called a test set. A test cycle is the combination of all possible test points (performed in
consecutive test sets) in a randomized sequence.


and condensable combustion gases in order to prevent contamination of the downstream
components.

A chemical or canopy hood removed combustion products from the test room. Airflow
through the hood was sufficient to remove cigarette and substrate combustion products
while not being high enough to influence the combustion processes in the test
chamber(s).

Following a test, the cigarette and sheets of filter paper were completely extinguished.
Calibration and Standardization

Calibrations of equipment were carried out at regular intervals and at any time when
equipment or test conditions indicated that evaluation and re-calibration were necessary.

The ignition test chambers were checked before use to insure that the front door seals
properly and that air movement in the test area does not introduce transient air movement
in the test chambers. Door seals were checked visually to ensure that they closed flush
against the chamber’s side wall and the latching device secured the door tightly. All
construction seams were inspected to ensure they were airtight, with no cracks visible on
any surface of the test chamber.

The stability of the air inside each test chamber was determined daily by placing a lit
cigarette in the test position on one or more layers of filter paper, then closing the
chamber door. Smoke being emitted by the cigarette rose vertically and showed no
turbulence within 150 mm above the lit end of the cigarette.

The humidity and temperature sensors used to record environmental conditions in the
conditioning room or the chamber and test room were checked for accuracy daily

The air draw apparatus used for igniting cigarettes was calibrated at the beginning and
end of this project.

Test Specimens and Standard Substrate Assemblies

Cigarette test specimens were protected from physical or environmental damage while in
handling and storage. Clean plastic gloves were worn at all times to minimize
contamination of the cigarette test specimens and filter paper substrates, which are
sensitive to contamination. If the specimens were to be stored for more than one week,
they were placed in a freezer reserved for the sole protection of cigarette specimens.

Prior to testing, cigarette test specimens were marked on their paper seam 5 mm and

15 mm from the tobacco end with a #2 graphite pencil. These marks are used to establish
a uniform bum and the start of the coal respectively.

26


APPENDIX D. CIGARETTE EXTINCTION METHOD

This test method measures the probability that a cigarette, placed on a substrate, will generate
insufficient heat to maintain burning of the tobacco column. Each test consists of placing a lit
cigarette on the horizontal surface consisting of a set number of layers of filter paper.
Observation is made of whether or not the cigarette continues to burn the full length of the
tobacco column. A number of replicate tests (composing a trial) are performed to obtain the
relative probability that the cigarette will be extinguished by heat abstraction by the substrate.
Four of these apparatus were used concurrently.

7.

Apparatus and Equipment

An environmental conditioning room provided an area adequate tor conditioning both
cigarettes and filter paper specimens. This room was maintained at a relative humidity of
55 % + 5% and a temperature of 23 °C + 3 °C and was continuously monitored.

A test chamber of the design photographed in Figures D-1 and D-2 was used for testing
the cigarette/substrate combinations.

A cylindrical support for the layers of filter paper, shown in Figure D-2, was of PMMA
and dimensioned as follows: outer diameter of 165 + 1 mm, inner diameter of 127 mm +

1 mm, and a height of 50 mm + I mm. A recess in the top, 8 = 1 mm deep, expanded the
inner diameter to 152 mm + I mm. Three or four legs raised the bottom of the holder
approximately 20 mm above the chamber floor.

A circular brass or similar metal rim, shown in Figure D-2 was used to hold the sheets of
filter paper flat against each other. The outside diameter of the rim was 150 mm + 2 mm.
The inner diameter was 130 mm + 2 mm. The thickness was 3 mm + | mm. The rim
surface was flat and smooth. A pair of parallel metal pins, each approximately | mm in
diameter and 8.1 mm + 0.05 mm apart, protruded approximately 20 mm toward the
center of the rim, spaced to keep the filter end of a conventional 25 mm circumference
cigarette from rolling. but without pressuring the filter. When cigarettes of significantly
different diameter were tested, other pairs of pins, appropriately spaced, were inserted
into the rim.

A cylindrical holder supported the cigarette in the test chamber prior to placement onto
the filter paper substrate. The cylinder was of a length and diameter to support the
cigarette in a vertical position, coal side up, without damaging the cigarette. The base
plate for the cylinder was just under 50 mm in diameter, and the holder weighed less than
70 g.

A butane gas lighter capable of producing a stable luminous flame for approximately 15
mm in length was used for lighting the cigarette. The cigarette was supported in a
horizontal position, with an air flow through the cigarette of 15 mL/s to 20 mL/s. The
draw time through the lit cigarette was sufficient to establish a coal equal to or less than 5
mm in length. Filtering media were used downstream of the cigarette to remove smoke


The Fire Safe Cigarette Act of 1990 (P.L. 101-352). Among other products, this Act
resulted in:

= Two methods for measuring the ignition propensity of a cigarette type?

* The Mock-up Ignition Method measures whether a cigarette causes ignition by
transferring enough heat to a fabric/foam simulation of a piece of furniture
(substrate). A lit cigarette is placed on one of three different mock-ups. Ignition
(failure) is defined as the char propagating 10 mm away from the tobacco column.
The procedure is repeated a set number of times and the percent of failures is
calculated.

= The Cigarette Extinction Method measures whether a cigarette, when placed on a
heat-absorbing substrate, burns long and strong enough to cause ignition had it
been dropped on a piece of furniture. A lit cigarette is placed on one of three
substrates consisting of a fixed number of pieces of common filter paper. Failure
is defined as the cigarette burning its full length. The procedure is repeated a set
number of times and the percent failures is calculated. [While the metric in this
test is the cessation of burning, it is not a test for “self-extinguishing” cigarettes.
Some cigarette designs that pass this procedure have also performed well in the
Mock-up Test, burning their full length without causing an ignition.]

The two methods produce similar results. Both were subjected to an interlaboratory
evaluation (ILE) to measure their reproducibility. In addition, NIST tested 20
commercial cigarettes and 5 experimental cigarettes using the two methods.

= A cigarette smoke toxicity testing plan.'” A panel of experts from government,
industry and academia developed a four-tier plan, proceeding from rapid and
inexpensive tests to longer, more costly measurements.

= Estimation of the societal costs of cigarette fires.”

Efforts to develop a Federal standard for less fire-prone cigarettes have been unsuccessful. In
June of this year, the State of New York became the first jurisdiction to enact such legislation
Other states are considering similar action.

On January 11, 2000, a major manufacturer of cigarettes announced that it would soon be test
marketing a modification of one of their cigarettes that would make them less likely to start a
fire. Having evolved from one of the patented ideas tested under the Cigarette Safety Act of
1984, the modification entails adding circumferential bands of low air permeability paper to the
paper that wraps the tobacco column. These bands were said to reduce the rate of burning.
making it more difficult for the cigarette to heat furnishings and cause ignition.

° Ohlemiller, T.J., Villa, K.M., Braun, E., Eberhardt, K.R., Harris, Jr, R.H., Lawson, J.R., and Gann, R.G.. Test
Methods for Quantifying the Propensity of Cigarettes to Ignite Soft Furnishings, NIST Special Publication 851,
National Institute of Standards and Technology, 1993.

' Lee, B.C., Mishra, L.C., Bums, D.M., Gairola, C.G., Harris, J.E., Hoffman, D.. Pillsbury, Jr., H.C., and Shopland,
DR,, “Toxicity Testing Plan,” Report No. 5, Technical Advisory Group, Fire Safe Cigarette Act of 1990, U.S
Consumer Product Safety Commission, August 1993



Figure 4. 95 % Confidence Intervals for the Relative Ignition Strengths (RIS) of
Conventional and Banded Cigarettes on Different Extinction Test Substrates

3 Layers 40 Layers
e °
‘ 1 I
#8
& oe
go i
Ss
2s .
38
é
.
2
3
Conventional Banded Conventiona Banded
Cigarette Type Cigarette Type
15 Layers
“TT
: s
Bo
§ o
2 1
zs |
° i
8

Conventional Banded
Cigarette Type

Table 8. 95 % Confidence Intervals for the Difference in Relative Ignition Strengths
of Conventional and Banded Cigarettes on Different Extinction Test Substrates
(RISpandea — RISconventional)

RISpandea — RUSconventional
3 Layers 10 Layers 15 Layers
-0.79 to -0.38 -0.98 to -0.69 -0.97 to -0.64

Vv. DISCUSSION

The above analysis shows that the banded cigarettes produced significantly fewer failures in both
test methods than did their conventional! counterparts. Table 9 puts these results in context with
the data from reference 9. The 14 best-selling commercial cigarettes in 1993 ignited the mock-
ups or bumed their full length on filter paper in virtually every test. [The results for one of these
cigarettes are shown in the first row.] Cigarettes A through F are other 1993 commercial
cigarettes that were expected, based on values of their physical properties, to have reduced

16


Three standard test fabrics were used, having the following nominal properties:

100 % Areal Density | Yarn Count Air Permeability
Cotton Duck (kg/m?) (per inch) Yarn Plies | (10° m’s"'m”)
#4 0.83 31x 24 4x4 5.1 tol0.2
#6 0.72 36x26 | 3x3) |S 1 t010.2
#10 0.50 40x28 | 2x2 10.2 1020.4

A fourth 100 % cotton fabric had an areal density of 0.36 kg/m’.

The polyethylene film used with the #4 cotton duck substrates had a thickness of
0.15 mm = 0.007 mm and an areal density of 0.012 kg/m’ = 0.005 kg/m’.

The substrates were formed by placing the fabric (and film) on the foam, then placing the
metal rim on top to ensure good contact between the layers.

Conditioning

The cigarettes were conditioned at a relative humidity of 55 % + 5 % and a temperature
of 23 °C = 3 °C for at least 24 hours prior to ignition testing. The cigarettes were stored
vertically, filter end up, in a clean 250 mL glass beaker, with a maximum of 20 cigarettes
per beaker to enable free air access to the specimens.

The substrate materials were also conditioned at a relative humidity of 55 % 2 5% anda
temperature of 23 °C + 3 °C for at least one week prior to ignition testing.

Procedure

Turn on the exhaust system designated for removal of test combustion products 30 min
prior to beginning testing.

Cover the chimney on the test chamber.

Select the substrate materials for the scheduled test. Place the assembly in the test
chamber at the geometric center of its bottom and place the metal test rim on top.

Place the cigarette holder on the center of the fabric.

Without delay, remove a cigarette from the conditioned space. Insert the unmarked end
of the cigarette into the cigarette ignition system and hold it in a horizontal position

Turn on the air draw, verifying that the air flow is 15 mL/s to 20 mL/s. Hold the ignition
flame or hot wire coil to the marked end of the cigarette for as long as is necessary to
achieve uniform ignition without passing the 5 mm mark.

Holding the cigarette vertically, coal end up and under a 600 mL beaker, transport the
cigarette to the test chamber.

ne
is)



National Institute of Standards
and Technology

Technical Note 1436

Natl. Inst. Stand. Technol.
Tech. Note 1436

34 pages (November 2000)
CODEN: NTNOEF

U.S. Government Printing Office
Washington: 2000

For Sale by the

Superintendent of Documents
U.S. Government Printing Office
Washington, DC 20402-9325


Since the response variables (i.e., ignition or non-ignition, full-length burning or not) observed in
each of the individual experiments addressed here are binary, use of a binomial-distribution-
based model for the data is appropriate. The primary assumptions are (a) that the binary
outcome for each measurement from each potentially different population occurs with a
particular fixed probability, pj, and (b) that the outcome of each measurement is independent of
the outcomes of all of the other measurements. Observations that meet these assumptions are
said to be “independent and identically distributed.”

The typical confidence interval used to estimate binomial proportions, in this case relative
ignition propensities, is based on the normal distribution and has lower and upper endpoints
defined respectively by'*

(np + 329-1) Syne (2 + Hn) + 4 pa ~ p)+D)

P=

and

(2np+ ty, + U4 tyy tape +2 ~ Hn) + 4M B)—D)
2m E52)

Pu =

where n is the number of mock-up or extinction tests done under a particular set of conditions,
p is the proportion of tests in which an ignition or a full-length burn occurred for the Mock-up
or Extinction Tests respectively, and z,,. 18 the upper-tailed critical value from a standard

normal distribution (i.e., 1.96 for a confidence level of 95 0 or @ = 0.05 ).

The typical confidence interval used to compare binomial probabilities from different
populations, in this case relative ignition propensities of different cigarettes under different test
conditions, is also based on the normal distribution.'* It has lower and upper endpoints defined
respectively by

on [é 1-p,) p,-p,) 111
4, =(b,- Bs) typ PTB) PIP) Tet ty
Mm n, 2m, n,

and

"4 Fleiss, J.L., Statistical Methods for Rates and Proportions. John Wiley and Sons, New York, 1981


propensities are different. The situation for the individual confidence intervals is analogous
except that there is no natural, general hypothesis of interest.

IV. RESULTS AND STATISTICAL ANALYSIS OF COMPARATIVE DATA PAIRS
A. Relative Ignition Strengths of Cigarettes 529 and 534 over Time

Table 1 shows the current data on the two experimental cigarettes and the corresponding data
from the 1993 ILE of the Cigarette Extinction Method. Specifically, the NIST single-laboratory
data from the ILE are included in the table.

Table 1. Relative Ignition Strengths of Cigarettes 529 and 531
(number of full-length burns/number of trials)

1993 2000 :

Cigarette | 3 Layers | 10 Layers | 1S Layers 3 Layers | 10 Layers | 15 Layers
529 LW Oe | 0169/24 024)
531 16/16 15/16 1416 22/24 19/24

Since the Cigarette Extinction Method test procedure, the laboratory conditions, and the substrate
material were the same as in the 1993 tests, and since the analysis of the 1993 ILE showed littic
if any dependence on the test operator, any changes observed in the relative ignition propensities
of the cigarettes are attributed to the cigarettes themselves. The 95 % confidence intervals for
the ignition propensity of each cigarette as measured at NIST in 1993 and in 2000 are shown in.
Figure 1. The large degree of overlap between the pairs of confidence intervals indicates that
there is no evidence of any change in relative ignition propensity of the two laboratory cigarettes
used in this comparison.

Table 2 lists approximate 95 % confidence intervals for the differences in relative ignition
propensities for these two cigarettes. The fact that the confidence intervals listed in Table 2 all
contain the value zero confirms the conclusion of no statistical change in the ignition
propensities of these laboratory cigarettes.

Table 2. 95% Confidence Intervals for the Difference in Relative Ignition Strengths
(RIS) for Cigarettes 529 and 531 over Time (RISz999 - RIS1993)

RIS 2009 - RIS; 993

Cigarette 3 Layers 10 Layers 15 Layers
529 -0.56 to 0.00 -0.19 to 0.12
531 ~6.18 to 0.19 0.3010 0.19

1


NIST Technical Note 1436

Relative Ignition Propensity of
Test Market Cigarettes

Richard G. Gann, Kenneth D. Steckler. and Schuyler Ruitberg
Building and Fire Research Laboratory

William F. Guthrie and Mark S. Levenson
Information Technology Laboratory

National Institute of Standards and Technology
Gaithersburg, MD 20899-8650

January 2001

U.S. Department of Commerce
Norman Y. Mineta, Secretary

Technology Administration
Dr. Cheryl L. Shavers, Under Secretary of Commerce for Technology

‘National Institute of Standards and Technology
Karen H. Brown, Acting Director


APPENDIX C. MOCK-UP IGNITION METHOD

This test method measures the probability that a lit cigarette, placed on one of three standardized
upholstery mock-ups, will ignite the mock-up to smoldering combustion. The mock-ups consist
of a sheet of fabric over a block of flexible polyurethane foam. One substrate has a sheet of
plastic film between the fabric and the foam to increase the overall thermal mass. A number of
replicate tests (composing a trial) are performed to obtain the relative probability that the
cigarette will ignite the substrate. Four of these apparatus were used concurrently.

1.

Apparatus and Equipment

An environmental conditioning room provided an area adequate for conditioning both
cigarettes and filter paper specimens, This room was maintained at a relative humidity of
55% + 5% anda temperature of 23 °C » 3 °C and was continuously monitored.

A test chamber of the design photographed in Figures C-1 and C-2 was used for testing
the cigarette/substrate combinations.

A square brass rim, shown in Figure C-2 was used to hold the fabric (and film) flat
against each other and the foam. The outside dimension of the rim was 200 mm + 2 mm.
The inner dimension was 150 mm = 2mm. The thickness was 3 mm + i mm. The nm
surface was flat and smooth.

A cylindrical holder supported the cigarette in the test chamber prior to placement onto
the filter paper substrate. The cylinder was of a length and diameter to support the
cigarette in a vertical position, coal side up, without damaging the cigarette. The base
plate for the cylinder was just under 50 mm in diameter, and the holder weighed less than
70 g.

A butane gas lighter capable of producing a stable luminous flame for approximately 15
mm in length was used for lighting the cigarette. The cigarette was supported in a
horizontal position, with an airflow through the cigarette of 15 mL/s - 20 mL/s. The draw
time through the lit cigarette was sufficient to establish a coal equal to or less than 5 mm
in length. Filtering media were used downstream of the cigarette to remove smoke and
condensable combustion gases in order to prevent contamination of the downstream
components.

A chemical or canopy hood removed combustion products from the test room. Airflow
through the hood was sufficient to remove cigarette and substrate combustion products
while not being high enough to influence the combustion processes in the test
chamber(s).

Following a test, the cigarette and substrate materials were completely extinguished with
a small stream of water.




When the cigarette has burned to the 15 mm mark, simultaneously replace the chimney
cover and open the chamber door, then gently remove the cigarette from the holder, and
move the holder to the front comer of the test chamber.

Gently lay the cigarette with the ash still attached onto the top of the filter papers so that
the “filter” end is placed between the appropriately sized cigarette anti-roll fingers. The
cigarette paper seam is turned up. Do not drop the cigarette onto the filter papers and do
not press the coal into the papers. If the ash falls off during any part of the transport or
positioning process, terminate the test and begin again; do not count the attempt.

Without delay, simultaneously remove the chimney cover and gently close the door.

Observe the burning cigarette. The smoke plume near the cigarette must remain
undisturbed. If it does not, this observation shall be noted on the test sheet.

Record the following results:

(1) The cigarette bums the full length of the tobacco column or
(2) The burning ceases before reaching the end of the tobacco column.

Ensure that neither the cigarette nor the filter papers are still burning.

Open the test chamber door to allow air to circulate throughout its volume. After the
chamber has cleared, prepare for the next test

Repeat the test with each cigarette the requisite number of times per trial. Calculate the
percentage of tests in which the cigarettes burned their full length.

Test Report
Report the following information for each trial:

Name of person performing the test

The temperature and relative humidity in the laboratory

Date of each test

Cigarette identification

Number of layers of filter paper per test

The percentage of tests in which the cigarettes burned their full length


Place the lit cigarette, still vertical, in the cigarette holder.
Simultaneously close the door and remove the chimney cover.

If the cigarette should self-extinguish while in the cigarette holder, terminate the test and
record the results as a self-extinguishment and note that this occurred in the holder.

When the cigarette has burned to the 15 mm mark, simultaneously replace the chimney
cover and open the chamber door, gently remove the cigarette from the holder, and move
the holder to the front corner of the test chamber.

Gently lay the cigarette with the ash still attached onto the top of the fabric so that the
coal end is located at the geometric center of the surface and the cigarette axis is diagonal
to the fabric warp. The cigarette paper seam is turned up. Do not drop the cigarette onto
the fabric and do not press the coal into the fabric. If the ash falls off during any part of
the transport or positioning process, terminate the test and begin again; do not count the
attempt.

Without delay, simultaneously remove the chimney cover and gently close the door.

Observe the burning cigarette. The smoke plume near the cigarette must remain
undisturbed. If it does not, this observation shall be noted on the test sheet

Record the following results:

()) Ignition: the char mark on the fabric propagates at least 10 mm from the
edge of the cigarette;

(2) Non-ignition: the tobacco column burns to the end without causing an
ignition; or

(3) Self-extinguishment: the coal goes out before the tobacco column is
consumed.

Extinguish the cigarette and the substrate materials using a water bottle.

Open the test chamber door to allow air to circulate throughout its volume. After the
chamber has cleared, prepare for the next test.

Repeat the test with each cigarette the requisite number of times per trial. Calculate the
percentage of tests in which the cigarettes burned their full length


where the test points were:

Test Test Duck
Point Cigarette ‘Type #
ee 529 Mockup 6
2 529 Mockup 10
3 531 __Mockup 4
4/531 | Mockup | 6 |

F. Evaluation of the Relative Ignition Propensities of the Banded Cigarettes

A third series of tests was performed to determine the relative ignition propensities of the
conventional and banded cigarettes. Both were tested using the two test methods. For the Mock-
up Ignition Test, additional testing was performed with a substrate consisting of the ivory cotton
fabric and the standard polyurethane foam. All component materials were randomized and
labeled. Eight test sets were performed for the fabric substrates, six test sets for the filter paper
substrates. The randomized sequence of Cigarette Extinction Test Method testing was:

where the test points were:

Test #
| Point Cigarette ——_|_ Layers
i Conventional _ 3
| 2 | Conventional 10
3 _Conventional IS
4s Banded 3
5 _ Banded 100
6 Banded Is



where n, is the number of mock-up or extinction tests done under a particular set of conditions
and #, is the proportion of tests in which an ignition or a full-length bum occurred for the mock-
up or extinction tests respectively.

Determination of whether or not an observed relative ignition propensity or a difference in the
relative ignition propensities for different pairs of test conditions significantly differs from a
hypothesized value with these confidence intervals simply requires checking to see if the
hypothesized value falls inside or outside the interval. If the hypothesized value is in the interval
then the hypothesis would not be rejected. If the hypothesized value is not in the interval then the
hypothesis would be rejected.

The advantages of these confidence intervals include ease of computation and familiarity
However, they depend on the central limit theorem, which states that the distribution of p will
be approximately normal if the sample size is large. How large a sample size is required for the
approximation to work well depends on the actual underlying relative ignition propensities.
When either of the relative ignition propensities in question is near zero or one, very large
sample sizes are required for the normal approximation to describe the behavior of the estimated
ignition propensities adequately. Based on the data presented in the next section, the normal
approximation would not work well for some of the comparisons of interest in this report

As a result, different methods for estimation and comparison of the relative ignition propensities
that do not depend on the applicability of the central limit theorem, but are more computationally
intensive as a consequence, are used throughout this report. In the alternative procedures used
here, confidence intervals are constructed numerically using the binomial distribution directly
The methods of Blyth and Still'* are used for the estimation of individual ignition propensities
and the methods of Coe and Tamhane"® are used for the comparison of different ignition
propensities. While requiring special software using complex algorithms, these methods provide
approximate confidence intervals that are guaranteed to attain their stated confidence levels
regardless of the sample sizes and true ignition propensities. In addition these methods provide
intervals that will be shorter than most other methods for obtaining well-behaved, approximate
confidence intervals for binomial probabilities or differences of binomial probabilities

As for the normal-distribution intervals, for any particular comparison being made with these
alternative confidence intervals statistical significance is determined by noting whether or not the
confidence intervals contain a hypothesized value. For example, for the difference of two
relative ignition propensities, where the natural hypothesized value is zero, the statistical
significance of the difference between the ignition propensities is determined by the intervals
inclusion or exclusion of zero. If the interval includes the value zero then the two ignition
propensities cannot be concluded to be significantly different from one another, while if the
interval does not include the value zero the appropriate conclusion is that the ignition

'S Biyth, C.R., and Still, H.A., “Binomial Confidence Intervals,” Journal of the American Statistical Association,
Vol. 78, March 1983, pp 108-116.

16 Coe, P.R., and Tamhane, A.C., “Small Sample Confidence Intervals for the Difference, Ratio and Odds Ratio of
Two Success Probabilities,” Communications in Statistics, Part B -- Simulation and Computation, Vol. 22, 1993, pp
925-938.

10