Q 

Ad 

Technical 

Study Group 

Cigarette Safety 

Act of 1984 

Cigarette Ignition 

of Soft 

Furnishings - 

a Literature 

Review With 

Commentary 

June 1987 

JOHN F. KRASNY 

Center for 

Fire Research 

National Bureau 

of Standards 
I Mission and Members 

The Technical Study Group on Cigarette and Little Cigar Fire 

Safety was established by Public Law 98-567, the Cigarette 

Safety Act of 1984. on October 30, 1984. Its mission IS to: 

'undertake such studies and other activities as it considers 

necessary and appropriate to defermine the technical and 

commercia/ feasibiiity economic impact. and other conse~ 

quences of developing cigarettes and little cigars that will 

have a minimum propensity to ignite upholstered furniture or 

mattresses Such activities inciude identification of the 

different physicai characteristics ol cigarettes and httie cigars 

which have an impact on the ignition of upholstered furniture 

and mattresses, an anaiysis of the leasibiiity of altering any 

pertrnent characteristics to reduce ignition propensity, and 

an anaiysis of the possibie costs and benefits. both to the 

industry and the public, associated with any such product 

modification." 

Copies of this or any other reports of the Technical Study 

Group may be obtained from Mr. Colin B Church, 

Secretariat, Technical Study Group, Consumer Product 

Safety Commission, 5401 Westbard Avenue. Washington. 

D.C.. 20207. 

MEMBERS: 

Richard G. Gann. Ph.D.. Chairman 

Edward Press, M.D., Vice-chairman 

Charles M Carey 

James L. Charles, Ph D. 

Joseph W Cullen, Ph.D. 

John C Gerard 

James F. Hoebel 

Preston H. Leake, Ph.D. 

Michael D. McGibeny 

E, Andrew McGuire 

Wendy H Poel 

Alan Rodgman, Ph.D, 

Alexander W. Spears, Ill. Ph.D. 

Henry Tovey 

Judith P. Wilkenfeld, Esq. 

PAST MEMBERS: 

Howard Eeales, 111 

Harry I. Cohen 

Craig G. Drummond 

Max Hausermann. Ph.D 
Cigarette Ignition 

of Soft 

Furnishings - 

a Literature 

Review With 

Commentary 

Technical 

Study Group 

Cigarette Safety 

Act of 1984 

June 1987 

JOHN F. KRASNY 

Center for 

Fire Research 

National Bureau 

of Standards 

- 

Abstract 

Literature pertinent to the ignition by smoldering cigarettes of 

upholstered furniture and mattresses (soft furnishings) was 

searched through early 1986. This included literature on the 

smoldering behavior of cigarettes in air. their behavior on a 

variety of substrates simulating soft furnishings: mechanism 

of smoldering in substrates; relative cigarette ignition resistance of substrates; and relative propensity of commercial 

cigarette packings to ignite substrates. 

According to the reviewed literature, the smoldering 

behavior of cigarettes on substrates differs from that of 

cigarettes burning in air. on substrates, cigarette tempera^ 

tures tend to be lower and burning rates slower These 

differences seem to be larger for substrates which ignite 

than for those which self-extinguish aner the cigarette burns 

out. The characteristics of soil furnishings which insure resis~ 

tame to cigarette ignition have been established. but those 

of cigarettes with low propensity to ignite furnishings have 

not. No mathematical model has been reported for the interaction of cigarette and substrate. but some empirical data do 

exist. 

.. 

ill 

Contents 

Abstract. ............................ iii 

List of Figures and Tables .................. 

Introduction .............................. 1 

Cigarette Characteristics ................ 3

Factors Which May Affect Cigarette Ignition Propensity ... 3 

General Characteristics of Cigarettes ........... 4

Free Burn Characteristics of Cigarettes .......... 4 

Cigarette Burn Temperature .............. 4

.vi 

Cigarette Burn Rate ....................... 7 

Non-Combusting Substrates ........... ... 11 

Technology .................... 12 

Other Investigators ................... 16 

Substrate Smoldering Mechanisms .......... 22 

Smoldering of Cellulosic Materials ............ 22 

Smoldering of Flexible Polyurethane Foam 

Cigarette Ignition Behavior ........ ... 24 

Temperature and Burn Rate of Cigarettes Burning 

on Substrates ......................... 11 

Smolder~Prone Substrates .................. 11 

Investigators at the Massachusetts Institute of 

Ignition by Electric Heating Coils 

Summary of Findings on Cigaretteisubstrate Interaction 

............... 19 

. 20 

......... 22 

Cigarette Ignition Behavior of Soft Furnishings ...... 24 

Effect of Fabrics ............. 25 

Effect of Padding Material ................ 27 

Effect of Interliner or Barrier Materials .......... 27 

Effect of Welt Cord ................ 27 

Effect of Furniture Geometry ........... 27 

Cigarette Ignition Behavior of Wildlife Materials ... 29 

Cigarette Ignition of Garments ............ 29 

Relative Ignition Propensity of Cigarettes ..... 30 

Conclusions .................. . 31 

Acknowledgements ....... .. ... 32 

References ...... ....... ... 33 

Appendix A: Test Methods for Determining 

Cigarette Ignition Resistance of Soft Furnishings ’ . . 38 

Appendix B: List of Patents .......... 

V 
D 

List of Figures and Tables 

Figure 1. Temperature Distribution in a Cigarette 

During Free Burning .................. .6 

Figure 2. Test Arrangement for Crevice Tests ....... .12 

Figure 3. TimeiTemperature Relationships Inside 

Cigarette Core in Air and on 

Two Substrates ....................... .13 

Figure 4. TimeiTemperature Relationships Measured 

in Four Locations Inside Cigarette Core ... .13 

TimeiTemperature Relationships at Fabric 

Surface and 20 mm Inside Vertical and 

Horizontal PU ~ Printcloth ............. 14 

Figure 5. 

Figure 6. TimeiTemperature Relationships Inside 

Cigarette Core and 20 mm Inside Vertical 

and Horizontal PU - Printcloth ........... 15 

Figure 7. TimeiTemperature Relationships Inside 

Cigarette Core and 20 mm Inside 

Horizontal and Vertical PU - Greige 

Duck Fabric. ..................... .15 

Figure 8. TimeiTemperature Relationships Inside 

Cigarette Core and 20 mm Inside 

Vertical and Horizontal PU - Bleached 

Duck Fabric. ....................... .16 

Figure 9. TimeiTemperature Relationships at 

Various Locations Inside Vertical and 

Horizontal PU .................. 

Figure 10. Arrangement for Inducing Ignition With an 

Electrical Heating Coil .................. 

Figure 11. TimeiTemperature Relationships Inside a 

Fabric Covered PU Block. with Electric 

Heating Coil (Various Output) Embedded. .. 

Figure 12. TimeiTemperature Relationships Inside a 

Fabric Covered PU Block, with Electric 

Heating Coil (15.5 kWM) Embedded . . 

Figure 13. Schematic Drawing of Smolder Wave in 

Fabric Covered PU Block. with Electric 

Heating Coil (15.5 kWirn2) Embedded 

Figure 14. Mini-Mockup Test Arrangement for 

Cigarette Ignition ...................... 

.17 

.ia 

.19 

.20 

.21 

.24 

vi 
Table 1. 

Table 2. 

Table 3. 

Table 4. 

Table 5. 

Table 6. 

Table 7. 

Table 8. 

Data Bases Searched .............. 1 

Summary of "Fire Safe" Cigarette Patents ... .2 

Characteristics of Commercial Cigarette 

Packings. Cigarette Packings Acquired 

about1980 ................... ..5 

Characteristics of 32 Commercial Cigarette 

Packings. Cigarette Packings Acquired 

About 1971 .................. .9 

Cigarette Temperature and Heat Flux 

Results with the Cigarette Resting on a 

Copper Plate ...................... 11 

Upholstered Furniture Components Listed 

in Approximate Order of Descending 

Cigarette Ignition Resistance .......... .25 

Typical Cigarette Ignition Test Results .... .26 

Cigarette Ignition Resistance of Typical 

FabriciPadding Material combinations .... .28 

vii 

- 

This literature survey was undertaken as part of the overall 

program mandated by the Cigarette Safety Act of 1984 (11. 

The Act seeks a reduction in the losses from fires caused 

by cigarettes inadvertently dropped on mattresses or uphol~ 

stered furniture (soft furnishing substrates' by modifying the 

ignition' propensity of the cigarette. The 1984 estimates for 

cigarette~caused fire incidents in residences are as follows: 

49,000 structural fires (7,9 percent of total), 1530 civilian 

deaths. 3950 civilian injuries. and 320 million dollars property loss (36, 19. and 9.3 percent of total. respectively) (2.31 

While the number of cigarette~caused fires have decreased 

over the last few years, they still represent the largest single 

cause of residential fire death. 

About 600 billion cigarettes are presently consumed in the 

U.S. annually 141: this means that only about one in 12 

million cigarettes causes a fire. It is not often possible to 

identify the cigarette packing or substrates from the accident reports. To identify specific properties that may be 

involved as causative factors, one has to rely on laboratory 

simulations of cigarette~caused ignitions. Much more work 

has been done in the area of identifying soft furnishing 

characteristics which increase their cigarette ignition resis~ 

tance (Section 6) than on identifying cigarette characteristics 

which reduce cigarette ignition propensity One study of the 

relative propensity of selected commercial cigarette pack^ 

ings to ignite soft furnishings mockups has been completed 

under the Cigarette Safety Act 161. A systematic investigation 

of the effects of certain cigarette parameters on their pro^ 

pensity to ignite sofl furnishings is currently in progress. 

The purpose of this literature survey is to provide a review 

of sources dealing with cigarette properties. substrate 

properties, and their interaction which may aid in the under^ 

standing of the mechanism by which cigarettes ignite 

substrates. It was written for readers having some familiarity 

with the field Relevant patents are listed in Appendix B. 

Thirteen data bases were searched as shown in Table 1 

Also searched were sources not included in these data 

bases, e.g.. special reports dealing with characteristics of 

cigarettes and soft furnishings and wildlife fires. appro xi^ 

mately 300 documents were initially identified. only about a 

third turned out to be germane to even a broad interpretation of the objective of this survey. Indeed, very little 

research has been published that directly relates cigarette 

combustion to substrate ignition mechanisms. 

Table 1. Data Bases Searched 

From Year 

to Present 

Chemical Abstracts 

Engineering Index Rase Engineering 

Compendix (Engineering Information Inc) 

National Technical Information Service 

World Textiles 

Textile Technology Digest 

Paperchem 

CRlSiUSDA 

RlOSlS Previews 

AGRICOLA 

FIREBASE 

Tobacco Abstracts 

World Patents 

Meetings 

1967 

1979 

1970 

1964 

1970 

1978 

1967 

1983 

1969 

1970 

1900 

1975 

1963 

'A soil iurnishing substrate is a combmalion of cover fabric and pad^ 

brig malerial, wth or vwlhoul well cord, in eirher lhe flal or the crevice 

Ouncture ot a horizonla1 and vertical furniture member) area For ex^ 

ample. lhe ilal area of a piece oi polyurethane loam covered with a 

collon cover iabnc. the crevice iram lhe same material will be consrd~ 

ered anofher substrate lor lhe present purposes, as would be the 

same subshale bul wilh lhe crgarelie covered wilh a piece o/ sheeling. as is oflen used in testing the cigarette ignition piopensty of soft 

furnishings (Appendix A) 

'ignitron in lhis review will mean self-susiainrng smoldering oi lhe substrate: such smoldeirng may or may not lead 10 llamng The lerm 

"seli-extinguishing cigaretle" has been wrdely used in many decussions oi cigaretles wilh a low ignitron propensity [e.g, 5j However. 

even cigarettes which sometimes sellkxlrngursh in arr can ignrle low 

ngarelte ,gnihon iesslance suhsliales. as can some hand-rolled 

cigarettcs which also commonly seliexlrngursh when not smoked 16~ 

8j Conversely. some cigaretles may burn their enlire lenglh wilhoul 

rgnrring high cigarelre rgnrtion fesislance substrates Consequently, we 

Shall use. mstead. the term ''low ignition propenstly" crgarettes in lhe 

followrng discussion Thrs lerm includes, bui is no1 limited to. 

cigarelles whrch sell~exiingursh on a substanlial number 01 substrates 

'A cigarerte packing is usually defined as a commercial venery. 

described by ils name. lenglh. diameler, whether menthol or "on 

rnenlhol, whelher wilh or withour hller. and by rls packing type 
One group of publications gathered for this survey was 

written by authors associated with the tobacco industry. It 

contains substantial information on such cigarette charac~ 

teristics as burn rate and temperature of the burning cigarette. Among the variables discussed are tobacco type, 

cigarette dimensions and packing density, filter parameters 

and paper porosity, and additives. The major objective of 

these publications seems to be to obtain basic understanding of the burning cigarette, with emphasis on reduction of tar, nicotine, CO. and other smoke components. 

Some of these papers are discussed below for general information on the burn process of cigarettes. However, because 

of their purpose, they have two major limitations for the 

present objective: (a) most of the data were obtained during 

the puff, while furniture and wildlife material ignition by a 

cigarette would be during the "free burning" period, and (b) 

the results were obtained with the cigarette held in air, not 

in contact with a substrate where oxygen exclusion, heat 

sink effects, reradiation from the substrate, etc. can affect 

the progress of the cigarette burn and its energy transfer to 

the substrate. 

Another large number of publications deals with the cigarette ignition resistance of soft furnishings. Test methods 

used to determine the cigarette ignition resistance of soft 

furnishings are listed in Appendix A. A discussion of papers 

on such test methods and the relative cigarette ignition 

resistance of various upholstery materials such as fabrics, 

padding, welt cords, decking, etc.. is included in a recent 

review of all aspects of soft furnishings flammability 19) and 

is summarized in Section 6. However, most of this work was . performed with one "standard cigarette, with only the 

substrates varied. Relatively few reports describe experiments with more than one cigarette packing [6,7.8.10-171 

(commercial cigarettes), [18.19] (research cigarettes). 

About 100 patents have been issued which claim to 

reduce ignition propensity (Table 2 and Appendix E). 

Concepts in these patents include chemical modification of 

the tobacco column or paper by means of various additives, 

insulating material around the cigarette, obstacles to smolder 

progress in the tobacco column or on the paper, etc. Evaluation of these patents is beyond the scope of the present 

survey. 

In the following, some basic cigarette characteristics will 

be discussed first, followed by the interaction between 

cigarettes and substrates. Then models of substrate smoldering and the relative cigarette ignition resistance of 

substrates will be discussed. This will be followed by a 

discussion of the relative ignition propensity of cigarettes. 

Table 2. Summary of "Fire Safe" Cigarette Patents [I 151 

..,.._ , . 

No. of % Of 

Patents patents 

Contain Ash andlor Reduce Heat Output 30 32 

Paper treated with borates, silicates. chlorine containing latex, fire proof paint 

Cigarette wrapped with aluminum foil, asbestos, fiber glass, etc 

Aluminum trihydrate added to tobacco 

16 17 

13 14 

1 1 

Extinguish at Selected Point 26 27 

Sliding or fixed non-combustible sleeve or band on cigarette 19 20 

Air gap in tobacco in cigarette 1 1 

Extinguish at Butt End andlor Prevention of Hot Coal Falling Off 21 22 

Non~combustible anchor or sleeve 3 3 

Addition of extinguishing materials between tobacco and filter (capsules containing water, 19 

Additions to Cigarette Holders to Contain Ash and Prevent Contact with Burning 18 18 19 19 

TOTAL 95 95 100 100 

Insertions in cigarette (barrier disc of porous non-combustible materials such as asbestos, 

aluminum, etc.) 

6 

18 

porous asbestos or metal discs, nylon band containing water) 

Cigarette 

2 
Cigarette I Characteristics 

- 

Factors Which May Affect 

Cigarette Ignition Propensity 

As an aid in understanding the general trend of this review, 

some of the factors which the author thinks may affect the 

ignition propensity of cigarettes are listed below. Some of 

these factors are interrelated. 

Cigarette length. The tobacco column length affects the 

time a cigarette burns and thus the probability of it being 

dropped and causing ignition, (Since it takes some 

conscious effort to light a cigarette, one may assume that 

a short burn time reduces the probability that the smoker 

becomes inattentive and drops the cigarette stub. Even if 

he does, the time available for ignition of the substrate is 

likely to be shorter ) 

Burn rate: This is presented as a change in length or 

mass with time. Whether a cigarette is burning in air or is 

being puffed, the burn rate affects the remaining cigarette 

length and thus the probability of dropping the cigarette 

and of ignition. In addition, burn rate of cigarettes on a 

substrate, which rnay be lower than that in air, affects 

length of exposure of the substrate and the probability of 

ignition 

Cigarette diameter. A decrease in cigarette diameter 

reduces the contact area between the cigarette and the 

substrate and reduces the available fuel. 

Packing density. Lower packing density (attained primarily 

by the use of expanded tobacco but also affected by the 

tobacco blend and cut width. i e.. the width of the 

tobacco strands) reduces the mass of available fuel. 

Tobacco type. The tobaccos used in various cigarette 

packings rnay vary in heat yield and burn rate due to 

variations in tobacco blend constituents and ratios. as well 

as in types and concentrations of flavorings and 

humectants. 

Paper parameters. Paper parameters cause differences in 

cigarette heat yield and burn rate The paper permeability 

affects the flow of oxygen from the outside air to the 

combustion zone and the diffusion of pyrolysis gases from 

this zone to the outside Chemicals are added to the ciga~ 

rette paper as smolder accelerants or retardants and to 

modify the appearance of the ash [20]. 

Filter characteristics. The presence and nature of filter tips 

also affects the flow of air through the cigarette [Zl]. 

Additional perforation is often provided in the paper 

covering the filter, reducing the flow of air through the 

tobacco column (ventilation; this is used to reduce the 

exposure of the smoker to smoke components). To 

compensate for the resulting change in combustion 

product yield or taste, other properties may be modified 

when a filter is added. Absence of a filter causes an 

increase in heat yield at the butt end 122). 

The following factors, while not cigarette properties, are 

integral to any laboratory study of cigarette ignition of soft 

furnishings: 

Spatial time-heat flux profiles of the smolder front passing 

over a substrate. There are no references to this profile in 

the literature. 

Contact of cigarette and substrate. This is at least partially 

determined by the cigarette diameter. as noted above. 

Other factors are the substrate surface characteristics and 

any intumescent behavior of the cigarette paper, its ash, 

or the fabric, which could have an insulating effect. 

Substrate characteristics Only some soft furnishings 

containing cellulose in either the fabric or the padding 

(cotton batting padding) or both. some acrylic fabrics. 

and some wildlife materials are susceptible to cigarette 

ignition. Both fabrics and wildlife materials must be of a 

certain minimum thickness and be fairly tightly packed. 

Ambient conditions Ambient wind speed. relative 

humidity, and temperature, as well as moisture content of 

the substrate and perhaps of the cigarette may have an 

effect on ignition propensity 

3 
General Characteristics of Cigarettes 

Most commercial cigarette packings have been found to be 

quite similar in cigarette and tobacco column properties, 

except for considerable variation in length, paper properties 

and perhaps in tobacco type. The details are given below. 

parameters of 128 commercial, U.S. cigarette packings was 

performed by Countryman of the U.S. Forest Service about 

1980 1231. His original premise was that certain cigarette 

packings are less effective initiators of wildlife fires than 

others. The length, diameter, weight, packing density, 

materials extractable with acetone such as crude fat, waxes, 

and gums, heating value (measured in a Parr adiabatic 

oxygen bomb) and ash content were determined. However, 

Countryman's work was terminated before these findings 

could be related to the ignition propensity of the cigarette 

packings. 

Table 3 shows that most of the above cigarette and 

tobacco properties varied over less than a factor of two for 

the various cigarette packings, with much of that range due 

to the variation in cigarette length. The similarity of most 

cigarette packings was also mentioned in tobacco industry 

communications e.g., [5]. Acetone extractives are an exception; they exhibit both a wider range and a higher coefficient 

of variation. (The relevance of acetone extractives to burning 

characteristics is not obvious but they are listed here to illustrate the differences in tobacco column characteristics). 

On the other hand, the cigarette paper varied considerably. The relatively large variation of paper weight as 

percentage of cigarette weight indicates differences in thickness or density (some of it is caused by tobacco column 

density variation). The variability of paper heating value and 

ash content per unit length indicates that the nature of the 

paper may also have varied. Furthermore, the heating value 

of the paper was found to be only about 70 percent of that 

of the tobacco, and its percent ash content considerably 

higher than that of the tobacco. 

Countryman stated that the probability of wildlife matter 

ignition from a single cigarette is low, as compared to that 

from other sources such as matches and firebrands. 

Reasons given for this low ignition propensity are the low 

weighffvolume ratio for cigarettes, the fact that they smolder 

rather than flame, and that the contact between cigarette 

and substrate is limited by the round configuration of the 

former as well as the natural roughness of the substrate. 

The author also states that the paper ashes first and may 

provide an insulating layer between coal and substrate. 

Loftus [22] published similar results for 26 filter and 6 

nonfilter cigarettes purchased in 1972. They are summarized 

in Table 4. He found somewhat different cigarette dimensions than Countryman found eight years later, but again 

found relatively small differences among the commercial 

cigarette packings he tested for the properties he measured. 

The largest study of the variability of some of the 

Free Burn Characteristics of Cigarettes 

Temperatures and burn rates of cigarettes in air have been 

widely reported. The absolute results for temperature 

depend on details of the measurement procedure, (location 

in coal, e-g., whether along the central axis or periphery; 

thermocouple size and orientation) but about 85OOC seems 

to be the maximum reported for the period between puffs. It 

is not clear whether the lower temperatures reported in 

many studies are due to differences in the manner in which 

they were measured or are real results; the necessary 

details for clarifying this are frequently lacking. Conse~ 

quently, reported temperature results obtained by various 

investigators can. at best, only be used for comparisons 

within each study, not between studies. 

from 4 to 6 mrnlmin in still air. It should, however, be kept 

in mind that cigarette burn temperature and burn rate are 

greatly affected by presence of a substrate, as will be 

discussed in Section 3. Work conducted under the Cigarette 

Safety Act at the time of this writing attempts to clarify this 

phenomenon further. 

Cigarette Burn Temperature 

Laboratories connected with the tobacco industry have 

published some very sophisticated studies of cigarette 

temperatures. The majority of their results were obtained 

during the puff on smoking machines. For reasons given 

earlier, this survey will concentrate on the measurements 

obtained during free burning of the cigarettes, i.e., of 

cigarettes suspended in air between puffs. Some of the 

studies from laboratories outside the cigarette industry use 

less sophisticated methods but are reported here because 

they contribute concepts of possible interest 124-32). 

A number of temperature measurement methods have 

been used: thermocouples inserted into the cigarette, optical 

pyrometry, infrared photometry, and X-ray scanning of 

beads embedded in the tobacco which melt at various 

temperatures. Most of these experiments were carried out 

with thermocouples. The effect of thermocouple size is 

discussed in a review article, as follows 1241. In one series 

of experiments, a decrease in thermocouple wire diameter 

from 0.100 to 0.025 mm increased the measured peak 

temperatures in cigarettes by 127°C. In another study, 

reduction of the thermocouple wire diameter from 0.20 to 

0.05 mm increased the peak temperature readings from 656 

to 812OC: No further increase in temperature was found 

with further decrease in thermocouple size. Based on the 

first study, it appears that accurate measurements of coal 

temperature require that thermocouples be no larger than 

0.025mm. 

Presented below are the relative effects of various 

parameters on peak temperatures reported by several 

authors. The absolute temperatures reported by these 

authors may differ because of the differences in measurement methods and thermocouple sizes. Temperatures were 

generally measured on the center line of the cigarettes. 

I 

Burn rates between puffs reported in the literature ranged 

. 

4 
Table 3. Characteristics of Commercial Cigarette Packings [22,25] 

Cigarette Packings Acquired about 1980 

Characteristics 

Cigarette’ 

Length of tobacco column (mm) 

Diameter (mm) 

Weight (9) 

Heat (J/rnm)t> 

Ash (girnrn) 

Packing density (gimrn3) x 103 

Tobacco’ 

Weight (Oh of cigarette weight) 

Heating values” (Jig) x 104 

Ash (%) 

(girnrn) x 10 3 

Acetone extractives (Wo) 

(Jirnm) x 103 

(Jirnrn) 

Paper” 

Weight (% of cigarette weight) 

Heating valueD (Jig) x IO4 

Ash (Vo) 

(Jirnrn) 

(girnrn) x 104 

Peak Temperatures, “C 

Center of cigarette9 

Surface of cigarettesd 

Time above 232OC, se 

Center of cigarettes 

Surface of cigarettes 

Average 

69 0 

79 

0 796 

188 7 

0 0020 

0 2237 

94 2 

180 8 

16 3 

16585 

178 

88 

3 128 

58 

1 1737 

78 

26 4 

17 

780 

442 

100 

80 

Standard 

Deviation 

88 

03 

0 098 

14 7 

0 0002 

0 0129 

10 

0 0456 

14 9 

13 

0 19 

18 

0 556 

12 

0 0799 

17 

56 

05 

~ 

85 

15 

17 

Coefficient 

of variation 

(Oh) 

12 8 

33 

12 3 

80 

10 0 

58 

10 

28 

83 

81 

10 9 

20 5 

17 8 

20 2 

68 

22 0 

21 3 

29 4 

~ 

19 

15 

21 

Range 

44 5 90 2 

6 6-8 5 

0 582-1 153 

143 3 230 7 

0 0010-0 0024 

0 1954-0 2742 

91.6~97.7 

1 5443-1.8677 

134 5222.8 

11.8-19.4 

0.97~2.21 

4.6-16.2 

1.555-5.304 

2399 

10288-1 4376 

30122 

11 9354 

0 7-13 6 

763-802 

394~510 

67-1 22 

62~94 

“1 28 cigarette packings 

‘Heating values measured in bomb calorirnetei 

35 cigarette packings 

“90 cigarette packings 

8 cigarette packings 

5 
Table 3 contains Countryman's temperature data for some 

of the 128 cigarette packings. measured with 0.125 mm 

chromelialumel thermocouples located at the center of the 

cigarettes or touching their periphery [25]. The cigarettes 

were held horizontally in air flowing at 1.3 mis in the direction of the smolder front movement. Th- average tempera^ 

ture obtained with this size thermocouple at the surface was 

47OOC. and in the center 77OOC. Countryman found that 

wood starts smoldering at or above 232T The time 

intervals over which the thermocouples indicated temperatures above this value averaged 100 seconds for the center 

and EO seconds for the surface of the cigarettes. 

temperatures of commercial cigarettes. and found an 

average center peak temperature of 730T and an average 

periphery temperature of 565OC [26]. With the cigarette 

insulated with glasswoo! ~ to obtain maximum possible 

temperatures supposedly simulating the cigarette inside. 

e.g.. a waste basket ~ the temperatures were 620 and 

570"C, respectively. 

Egerton. et al., using the optical records of beads with 

differing melting points embedded in the tobacco, found a 

peak free burning temperature at the apex of the core of 

820QC. while the maximum at the periphery was about 

616T [27]. 

Boyd. et a/., reported free burning and puff temperatures 

for a number of cigarettes in 1972 [29]. For (presumably 

British type) cigarettes, peak free burning temperatures were 

about 785OC. and puff temperatures, 820 to 85OOC. The 

corresponding temperatures for hand rolled cigarettes were 

620 and 78OOC. and for cigars, 600 and 68OOC. A certain 

pipe tobacco free burned in the pipe (with some puffing to 

keep it burning) at 640OC; the same tobacco free burned in 

a cigarette at 79OOC. Boyd also found that puff temperatures of cigarettes from Australia, Great Britain, Denmark, 

France, Japan, and the U.S. were within the range of 800 

to 9oooc. 

Gugan calculated that tobacco combustion would occur 

at about 12OOOC with all the ash in place, and 820°C 

without the ash cover of the smolder cone [30]. His actual 

measurements produced lower values, about 820T with 

the ash in place. He ascribed this to cooling by conduction 

through the ash, to the convective air flow pattern at the 

smolder cone, and to subsequent radiation and convection 

losses. 

By use of infrared photometry, peak peripheral puff 

temperatures of typical cigarettes were found to be 830~ 

900OC. and free burning temperatures about 700'C when 

the ash was partially removed from the smolder cone pi]. 

With the ash in place, the results were 830-9OO0C. and 500~ 

6OOOC. respectively. Peak peripheral puff temperatures for 

Cigarettes made with 100 percent Bright. Burley, and 

Turkish tobaccos varied only from 908-928°C. 

In 1956, another investigator measured free burning 

Alteration of burn temperature was considered as a 

means to reduce the polynuclear aromatic hydrocarbons in 

the smoke [32]. However, a wide range of tobacco additives, in concentrations of up to 50 percent, including free 

radical inhibitors and initiators, organic and inorganic salts, a 

number of inorganic compounds including lead borate 

glass, certain catalysts and flame retardants, had only minor 

effects on puff peak centerline temperature. 

In contrast to the previous papers which contained 

temperatures measured only in one or two locations, Baker 

published several profiles of temperature distributions in 

British cigarettes [28]. A free burn profile is reproduced in 

Figure 1; it gives temperatures separately for the gaseous 

and solid phases in the burn cone. The solid phase temperatures were measured by means of an infrared probe, the 

gaseous phase temperatures by means of thermocouples. 

He found relatively small differences between the solid and 

gaseous phase temperatures at any location The maximum 

temperature measured ~ at the center of the cone, approximately 2 mm from its apex - was 775OC, at the periphery, 

somewhat greater than 5OOOC. The distances between the 

isothermic zones at the periphery are of interest. At the cigaFigure 1. Temperature distribution in a 

cigarette during free burning ("C). 

e DIRECTION OF 

TEMPERATURE OF SOLID GAS FLOW 

2 4mm U 

-2 0 2 4 6 8 10 

DISTANCE FROM LINE OF PAPER BURN (mm) 

TEMPERATURE OF GASES 

-2 0 2 4 6 8 10 

DISTANCE FROM LINE OF PAPER BURN (mm) 

6 
rette surlace, the 500% gas and solid temperature zones 

extended from approximately the paper burn line to 2 mm 

into the smolder cone. The corresponding distances for the 

30OOC or higher solid phase zone were 3 mm from the 

paper burn line towards the butt end to 5 mm into the 

smolder cone for the solid phase For the gaseous phase. 

the corresponding distances were 1 and 8 mm. As will be 

discussed later, burn cone geometry and very probably 

temperature distribution change when the cigarette is in 

contact with a substrate. 

Cigarette Burn Rate 

Burn rate is of interest to the cigarette industry because it 

affects the number of puffs per cigarette, levels of smoke 

constituents, and other properties. A fast burn rate was also 

often hypothesized to correlate with increased ignition 

propensity However, results of experimental work conflict 

with this concept [6.19]. Ignition of a substrate requires not 

only a critical heat flux but also a critical exposure time. As 

will be discussed in Section 4, below, the cigarette burn rate 

is altered by the presence of a substrate, Free burn rate is 

briefly discussed here because it can be considered a basic 

characteristic of cigarettes. 

This discussion is based primarily on several major 

studies (33.371 American and Hungarian type cigarettes are 

discussed. In three of these studies, the burn rate was 

measured on horizontally suspended cigarettes. Rice's study 

was conducted on Canadian cigarettes containing essen~ 

tially all bright tobaccos; vertical cigarettes were tested with 

the burn moving downwards [37]. The effects of various 

parameter changes were generally found to be similar in all 

studies 

The basic device for measuring cigarette burn rate 

consists of a holder for the butt end of the cigarette. trip 

threads touching the horizontal cigarette (usually 40 rnm 

apart), and a timer to determine the interval at which the 

threads break 133). Burn rate measured without puffing is 

called the "free" or "static" burn rate. Linear burn rate is 

usually expressed in mmimin and mass burn rate in 

mgimin The latter is usually calculated from the linear burn 

length and the packing density. 

uring the burn rate of cigarette paper separately, with 

bottom ignition of vertically held specimens [38]. Burn velocities of 155 to 215 mmimin were observed; these velocities 

are greatly in excess 01 those of cigarettes. Some of the 

papers did not burn. 

cigarettes, sampled in 1980, varied from 4.1 to 5.9 mmimin 

1391. By contrast, rates of 1.8 to 3.6 mrnimin were reported 

in 1930 [16.17]. With the coal ends down, the burn rate of a 

1980 cigarette packing increased by 30 percent, with the 

Corbet and Schurer described an apparatus for measThe burn rate of 14 filter and three nonfilter U.S. 

coal end up, it decreased by 6 percent 1391. An increase in 

external air movement in the direction of the burn from 3 2 

to 9 0 kmihr increased the linear burn rate from 5.0 to 8.0 

mmimin A further increase in wind speed decreased it 

slightly to 7.5 mmimin. Wind perpendicular to or against the 

burn direction extinguished some of the cigarettes. 

Japanese investigators found no significant differences in 

horizontal and vertical (coal end down) burn rates for 

cigarettes from three packings [14], The method by which 

these somewhat tinexpected results was obtained was not 

described in detail The burn rates of these cigarettes were 

not affected by the packing densities indicating that other, 

nondisclosed factors affected the burn rate. The ignition 

propensities of these cigarettes on a number of upholstery 

substrates did not vary signilicantly. 

Ninety-five cigarette packings available in Germany in 

1982 had burn rates from 2.1 to 5.1 mmimin 1401 This is a 

lower range than that given for U.S. cigarettes This may be 

a true finding or may be due to a difference in the meas 

uring method, which is not described in the German paper. 

A specially low burn rate was found for some oval 

cigarettes. 

to the cigarette circumference for any one tobacco 

blendipaper combination [37]. Resnik, et ai., reported that 

an increase in circumference from 23 to 26 mm decreased 

the linear burn rate from about 5.5 to 4.7 mmimin and 

increased the mass burn rate from 62 to 77 mgimin [33.34]. 

Arany~Furessery. working with Hungarian cigarettes, found 

similar effects of the diameter on the two burn rates 1361. 

Resnik. et ai., found that the mass burn rate was gener~ 

ally not affected by packing density 133,341. The linear burn 

rate was approximately inversely proportional to packing 

density, with an increase in packing density from 0.22 to 

0.36 gicm' producing a decrease in linear burn rate from 

6.7 to 4.2 mmimin. 

tobacco types to the same firmness (which may have 

resulted in different tobacco column weights) differed in 

burn rate, as follows [33]: 

Rice found the mass burn rate to be directly proportional 

Resnik, et ai.. also found that cigarettes made from three 

Burn rate 

Tobacco rnrnlmin mglmin 

Turkish 33 52 

Bright 5.3 69 

Burley 62 77 

Increasing the cut width from 0.4 to 1 mm resulted in a 

decrease of burn rate from 6.0 to 5.2 mmimin [35]. For a 

Hungarian tobacco blend, an increase in cut width from 

0.57 to 1.19 mm decreased the linear burn rate by appro xi^ 

mately 8 percent and the mass burn rate by 17 percent 

136). Rice, ef ai.. found that an increase in cut width from 

0 35 to 0.61 mm decreased the mass burn rate from 66 to 

54 mgimin [37]. 

The paper characteristics can be adjusted to modify the 

cigarette burn rate somewhat. The major variables used for 

this purpose are: fiber composition, weight and bulk density, 

7 
the type of filler and its concentration and distribution 

throughout the paper. air permeability4 or porosity, and 

smolder promoting chemical additives [20.41.42). Permeability is generally expressed as "CORESTA." in 

cm3/min.cm*.cbar: it increases with increasing air permeability. Alternatively, air Permeability is often expressed in 

older literature as a "Greiner" number. Le., the number of 

seconds required for 50,000 mm3 of air to pass through 

1,950 mmZ of paper.' Consequently, the higher the Greiner 

number. the lower the porosity. 

Permeability can be increased by electrostatic, laser, or 

mechanical perforation of the paper. Other means are used 

to vary the inherent porosity" such as manipulation of the 

fibers during paper forming. reduction of paper weight, 

and/or use of paper fillers, e.g., CaCO, [ZOI. These methods 

have different effects on burn rate: increasing the porosity 

mechanically does not affect the mass burn rate, while 

increasing the inherent paper porosity increases both the 

linear and mass burning rates 133-37,421. However, beyond 

a permeability of about 80 cm3/min~cm2~cbar. no additional 

increase was found 1361. These relationships held for widely 

varying cigarettes. 

An empirical formula for computing the effects of the cigarette property changes on the mass burn rate was proposed 

by Rice, el a/.,[37]: 

r. 

L B = - [Bw + 0.70 (Mw - M) + 0.34 (Pw - P) - 

0.17 (Tw - T)] (1) cw 

where B = "predicted rate of burn, mgimin 

Bw = rate of burn of "measured cigarette, 

C = circumference of "predicted cigarette 

Cw = circumference of "measured" cigarette 

M = moisture content of "predicted" cigarette 

Mw = moisture content of "measured cigarette 

P = paper porosity of "predicted cigarette 

Pw = paper porosity of "measured cigarette 

T = cuts per inch of tobacco of "predicted 

Tw = cuts per inch of tobacco of "measured 

mgimin 

cigarette 

cigarette 

By correcting for packing density equation 1 can be readily 

modified to make possible the predlction of linear rate of 

burn , r. 

LL 6 -_ [Bw + 0.70 (Mw - M) + 0.34 (Pw + P) - - wcw 0.17 (Tw - Til (2) 

where L 

W 

€3, 

= length of "predicted cigarette (tobacco 

= weight of "predicted cigarette (tobacco 

= linear rate of burn, rnmimin 

portion only) 

portion only) 

These formulas were confirmed by actual burn rate meas 

urements on experimental cigarettes with two levels of each 

of the following variables: cigarette weight, circumference, 

cut width, moisture content, and paper porosity 1371. 

Other parameters also have been reported to have an 

effect on the burn rate, including relative humidity and 

smolder promoters or retardants. Three studies showed that 

burn rate decreases with increasing cigarette moisture 

content, while cigarette temperatures are not found to be 

greatly affected [15,35,43]. When conditioned at 20°C and 

67 percent relative humidity. a commercial cigarette burned 

at 4.8 mm/min; at 28% and 25 percent relative humidity, at 

5.6 mmimin 139). Another author reports a burn rate 

decrease of 12 percent with an increase in moisture content 

from 12 to 16 percent, and the temperature constant 1331 

Rice, et a/., showed that an increase in moisture content of 

cigarettes from 4 to 20 percent caused a decrease in 

vertical mass burn rate of 10 mgimin for three cigarettes 

varying in tobacco type and thus burn rate 1371. However, 

increasing concentrations of two humectants added to the 

tobacco, from 0.2 percent glycerol and 0.2 percent propylene glycol to a 1.4 percent concentration of both humectants produced the following small effects: increase in 

moisture content from 11.3 to 11.9 percent, free burn rate 

increase from to 4.9 to 5.3 mmimin. and mass burn rate 

increase from 61 to 66 mgimin 1331. 

Tobacco additives have been studied widely. Below we 

present summaries of some of these studies. In one of 

these, the same concentration of cations was added to all 

experimental cigarettes [41]. The effects on free mass burn 

rates were as follows, in descending order: 

- 

For Na-salts: bicarbonate = 

carbonate > nitrate > phosphate, dibasic phosphate, 

chloride> sulfate > monobasic phosphate; 

For nitrate and acetate, the order was 

Na>K>Li>Ca>Mg>NH,. Ca, Mg, and NH, nitrates 

could not sustain the smolder of a model cigarette by 

themselves. 

By the further addition of K-maleate (K, 0.5 percent) or 

Na-malate (Na. 1 .O percent) as a coexistent salt, the order 

of the burn rate retarding effect of NH,-salts was 

sulfate>chloride7 nitrate2carbonate = acetate. 

Chemical additives to the paper can be mixed with the 

cellulose slurry as fillers or applied as coatings to the paper 

surface in the form of very fine crystals [20]. Such chemicals 

can be used to affect burn rate or to affect the nature of the 

ash, e.g.. white or mottled appearance. Some that were 

tested in the laboratory are listed below (201. 

'CORESTA 10 corresponds roughly lo a Greiner 45 readmg: 30 to 18; 

50 10 12.5; and 70 lo 10. 

"'Permeability" shall be used as a term lor arr passage due to bolh "inherent porosily" which can be regulated in paper manufacture. and 

postpaper forming (mechanical or electrostatic) perforation 

8 
Burn Accelerators 

Alkali metal citrates 

Alkali metal tartrates 

Alkali metal acetates 

Alkali metal malates 

Alkali metal formates 

Alkali metal phosphates 

Alkali metal nitrates 

Alkali metal sulfates 

Alkali metal carbonates 

Alkali metal halides 

Ash Burn Citrates and phosphates are the most widely used addi~ 

tives to today's cigarette papers. On paper which had burn 

rates of 4.0 mmimin and 53 mgimin when untreated, a 2 

percent concentration of sodium citrate raised the burn rates 

of cigarettes to 5.5 mmimin. and 72 mgimin. while other 

citrates had less effect. Similar burn rate increases were 

observed when certain phosphates (1 percent PO, i, and 

sodium salts (0.5 percent Na.) were added to the paper 

WI. 

In summary, the effects of changing the inherent and 

mechanically or electrostatically-induced paper permeability 

and of modifying chemicals on the free burn process have 

Conditioners Retardants 

NH,H,PO, NaBO, 

Na,B,O, 

Na,MoO; 

AICI, 

Urea 

Table 4. Characteristics of Commercial Cigarette Packings [23] 

Cigarette Packings Acquired about 1971 

, 

Characteristics 

A. 26 filter cigarette packings 

Cigarette 

length (mm) 

weight (si 

butt temperature ("C) 

Tobacco 

weight (% of cigarette weight) 

heat (Jimm') 

packing density (gimm') x 10 

B. 6 Non-filter cigarette packings 

Cigarette 

length (mm) 

weight (9) 

butt temperature ("C) 

Tobacco 

weight (Oh of cigarette weight) 

packing density (gimm) x 10 

heat (Jimml) 

Paper 

weight (Vo of cigarette weight) 

Average 

86 

105 

659 

74 4 

42 

0 27 

79 

103 

695 

94 76 

0 27 

43 

5 23 

Coefficient 

Standard of variation 

Deviation (Oh) Range 

6.0 7.0 

0.07 6.7 

25 3.8 

80W 00 

0.96~1.23 

601~711 

57 76 59 7-80 3 

01 24 3 9-4 6 

0 01 38 0 254 0 294 

7.0 9.0 

0 05 5.8 

39 0 5.6 

0.33 04 

0.01 3.7 

0.20 4.7 

70~80 

0.957-1.094 

627~722 

94 24 95 20 

0 259-0 286 

4145 

0 33 04 4 80-9 76 

'Heating values measured in bomb calorimeter 

9 
been extensively studied empirically, but are not well understood [20,42]. The effect of some of these factors on ignition 

propensity has been investigated as part of the work under 

the Cigarette Safety Act and will be reported in the near 

future. 

The following is a qualitative summary of the effect of 

cigarette construction variables on burn rate: 

Effect on Burn Rate 

increase in Linear, mmlmin Mass, mglmin 

Cigarette 

Tobaccoa 

circumference decrease increase 

moisture content decrease decrease 

packing density decrease no effect or decrease 

cut width decrease decrease 

permeability 

Paper 

inherent increaseb increaseb 

mechanical no effect no effect 

citrate content increase increase 

"Tobacco type and additive (humectants. etc) confent also affecf burn 

rate 

"NO effect beyond 80 CORESTP 
Temperature and Burn Rate I of Cigarettes Burning 

on Substrates 

- 

Non-Combusting Substrates 

The temperatures at the center lines of 26 filter and 6 non~ 

filter cigarettes placed on asbestos hoard were measured in 

1972 by Loftus [22] using 0.05 mm chromelialumel thermo~ 

couples. The average results, along with some physical 

property data, are shown in Table 4. Loftus reported that 

there were no differences between peak, center line tern per^ 

atures in the filter and non-filter cigarettes when measured at 

25 and 51 mm from the butt end. At 3.2 mm from the butt 

end, the nonfilter cigarette temperatures were on the 

average 36OC higher than the filter cigarette temperatures. 

A similar study had been carried out in 1969 by Behnke. 

He used a highly conductive. 0.075 mm thick. copper sheet 

(size not given) as the substrate, with 0.25 mm 

chromelialurnel thermocouples attached to the copper plate 

[43]. Obviously. a copper sheet differs considerably in heat 

conductivity and other characteristics from fabrics used in 

upholstery, but Behnke's work may still he valid for comparison of the properties of various cigarette packings. The filter 

and nonfilter cigarettes were preconditioned by drying at 

110T for 16 hours followed by desiccating at room tern per^ 

ature for 8 hours Some were tested dry, immediately after 

removal from the desiccator. arid others after a further 

conditioning at 24OC and 65 percent relative humidity. The 

cigarette temperatures and heat flux (as measured by the 

temperature rise of the copper plate) results for 16 cigarette 

packings are summarized in Table 5. The temperatures 

were much lower than those measured by Loftus with the 

cigarettes resting on the asbestos sheet with the ther~ 

mocouples in contact with the cigarette. For comparison. 

Behnke reported conditions at which a cotton fabric (unde~ 

fined) was found to ignite under several experimental conditions: in a heated vessel at 385% on a hot plate at 465% 

and in contact with a hot wire at 518°C. A radiant exposure 

of 28 kWim2 for 30 seconds (equivalent to a black body 

temperature of about 560%) also ignited the fabric. 

We conclude the following from Behnke's work: 

There were no consistent effects on burn temperature or 

heat flux due to drying the cigarettes. This has also been 

reported by others for temperatures inside cigarettes 

[I5351 

There were no systematic differences between the filter 

and nonfilter cigarettes; since these were commercial 

packings. parameters other than the presence or absence 

of a filter undoubtedly were also varied. 

The temperatures and the heat flux levels measured on 

the copper sheet are sufficient to account for ignitions of 

cellulosic soft furnishings and wildlife [25]. even though 

the reported values are probably lower than actual peak 

vaiues. 

Smolder-Prone Substrates 

Beiow is a review of temperatures measured inside 

cigarettes at their interface with substrates and inside poly 

urethane substrates The core temperatures of cigarettes 

Table 5. Cigarette Temperature and 

Heat Flux Results with the Cigarette 

Resting on a Copper Plate [43] 

16 Commercial Cigarette Packings Acquired in 1969 

Coefficient 

Standard of variation 

Average .DeA Temperatures, OC 

dry 490 35 71 

conditioned 492 45 91 

I B. Heat flux. kW/mz I dry 40 6 67 16 4 

conditioned 40 6 64 15 7 

'dried at 1 iO°C cooled in desiccator 8 hours 

dried and cooled as above, conditioned for 8 hours at 

24OC and 65% r h 

11 
were found to be lower when they burned on smolder-prone 

substrates than when they were burned in air. Substrate 

ignitions were shown to occur at cigarette centerline temperatures as much as 250T below those of the cigarette 

burning in air. The cigarette centerline temperature rose only 

after the substrate started smoldering and there was heat 

feedback. One could question whether the time-temperature 

characteristics of cigarettes obtained in air are relevant to 

their ignition propensity. A more detailed summary of these 

findings is given in Section 3.4. 

Several investigators [44-511 placed cigarettes on 

substrates consisting of cellulosic (cotton or rayon) fabrics 

over glass fiberboard, polyurethane foam, and other 

paddings. Both flat and crevice substrates were used. 

Temperature measurements were carried out with thermocouples embedded inside the cigarette, at the cigaretteisubstrate interface, on the fabric surface under and at 

various distances from the cigarette, and inside the padding 

at various distances from the cigarette. As will be seen, both 

the peak temperatures and the duration of the timetemperature peaks determine whether selfsustaining, smoldering ignition of the substrate occurs or whether the 

substrate self-extinguishes. Unfortunately, some of the 

papers which present time-temperature curves did not 

differentiate between occurrence of self-sustaining ignition. 

or smoldering of the substrate in the vicinity of the cigarette 

and self-extinguishment of the substrate when the cigarette 

went out. 

Furthermore, the degree of contact between the thermocouple and the substrate or the cigarette is a somewhat 

uncontrolled variable in such experiments. Cellulosic 

materials shrink and often visibly move during charring: 

cavities bordered by molten material or char are formed in 

polyurethane foam. These can affect the contact with the 

thermocouple and the resulting temperature readings. 

Investigators at the Massachusetts Institute 

of Technology 

The most extensive work in this area was carried out by 

Salig. et a/. [44]. This was summarized and extended by 

Tesoro [45]. The following discussion will start with temperatures measured inside the cigarettes, followed by those 

obtained at the fabricipadding interface and inside the polyurethane foam. Both flat and crevice geometries and 

covered and uncovered cigarettes were used, as well as a 

set of three fabrics, with one of them finished in various 

ways. 

cigarettes on the substrates. Figure 3 shows the timetemperature traces obtained by thermocouples located 

about 25 mm from the tips of the cigarettes, at the cigarette 

centerline. The highest, and by far the narrowest, peak at 

700T was obtained with the cigarette burning in air. The 

relatively low peak temperature reported may have been 

due to use of large diameter thermocouples which were not 

described in these papers. When the cigarette was placed 

on a substrate consisting of a 120 g/mZ cotton printcloth 

over polyurethane foam6 in a crevice configuration, with the 

Figure 2 shows Salig's experimental arrangement for the 

cigarette covered with another piece of the same printcloth, 

the substrate did not ignite. However, the cotton fabric 

showed some localized char and the polyurethane foam 

showed a lOmm deep trough. The peak temperature inside 

the cigarette was about 62OoC. i.e., somewhat lower than 

that inside the same cigarette burning in air. The temperature peak was wider, indicating a lower burn rate. Explanations offered by the authors are the heat sink effect of the 

substrate and competition for the available oxygen by the 

substrate (which would be minimal if the substrate did not 

ignite); slowing of the oxygen supply rate by the fabric on 

top is an additional factor. 

- 

- 

Figure 2. Test arrangement for crevice 

tests. 

Polyurethane foam lPUl blocks covered 

with Upholstery fabric / 

Print Cloth cover 

over Cigarette 

All dimensions in millimeters 

Thermocouple 

When the cigarette was placed on a polyurethane foam 

block covered with a scoured and bleached, 320 g/m2, 

cotton duck, ignition occurred. The temperature rose to a 

50OoC "plateau" (slightly descending in this case, essentially 

level in others) and then ascended to a peak of about 

620°C. During the plateau time, smoke generation 

increased and the smoke assumed a yellow color, indicating 

polyurethane foam pyrolysis and probable smolder. Thus, 

polyurethane ignition occurred at a cigarette core temperature of about 500°C. After ignition, heat feedback from the 

smoldering polyurethane foam increased the cigarette core 

temDerature. 

. 
Figure 3. Timeltemperature 

relationships inside cigarette core in 

air and on two substrates. 

- Cigarette burning in air. 

-__ Cigarette in crevice of printcloth upholstery fabric1PU block 

mockup; cigarette covered by small piece of fabric 

(printcloth1 PUlcrevicelcovered). 

Cigarette in bleached ducklPUlcrevicelcovered mockup. 

800 I I I I 1 I 

In air 

/A 

600 - .?Bleached duck. 

f \. 320 g/m2 

j \,ignition - 

-. ; \. 

$ 400 - \.-. '. 

Y 

3 

a 

Y 

a 

\. 

\ 

- 

',Print Cloth, 120 gIm2 

\ Self-extinguishing '. , \. 

-. \. - 

'\ 

t 

200 - I '. \. 

.. \. 

I 1 I I , I- 

._ ---_ ..-, 

--- -- 

OO 300 600 900 1200 1500 1800 2100 

ti 

TIME Is1 

0. 

smoldering about 20 minutes after cigarette placement, 

substantial heat feedback to the cigarette core apparently 

occurred. 

The cigarette glowing zone in air was reported to have 

been approximately cylindrically shaped. with a 10 rnrn 

dimension along the cigarette axis. Covered cigarettes on a 

printcloth substrate had a conical burn zone, with a 15 rnm 

length when the cigarette had burned about half its length, 

Figure 4. Timeltemperature 

relationships measured in four 

locations inside cigarette core. 

Conditions as in Figure 3. 

The sequence of events was as follows: the cigarette 

causes smoldering of the fabric, and only if the fabric is 

sufficiently smolder-prone can it ignite the polyurethane 

foam. Essentially none of the polyurethane foam types 

presently used in furniture, including the polyurethane foam 

used in this work. ignites from a cigarette alone unless they 

are covered by a srnolder~prone fabric [9]. 

Figure 4 shows timeitemperature traces for four thermocouples embedded in the cigarette core; the first traces 

r1C'') are the ones shown in Figure 3. In the majority of the 

cases, the mid-column (second and third) peaks inside the 

cigarettes were slightly higher than the first ones and the 

last peak was lower than the others, perhaps due to higher 

heat losses near the cigarette butt. 

The shapes of the sequential peaks inside the cigarette 

burning on the bleached duck substrate differed considerably, indicating a complex interaction between the fabric, 

polyurethane foam, and the cigarette during ignition of first 

the fabric and then the polyurethane foam. The above^ 

mentioned plateau decreased in height and width with 

smolder progress through the cigarette. This indicates that 

as the substrate smolder grew, the cigarette temperature 

was at first lowered. When the polyurethane foam started 

. 

Print clothlPUlcrevicelcovered 

-17417 . .- 

620 

380 

256 

128 

0 

40 35 30 25 20 15 10 5 0 

Bleached duck11 

C. 

L 

40 

\ is00 

'Ulcrevicelcovered 

740 

620 

500 

380 

25 6 m 128 

35 30 25 20 15 TO 5 0 0 

TIME (minutes) 

W 

K 

3 + 

W 

a 

9 

W 

c 

3 

13 
and 25 mm near the butt. With heavier, more smolder-prone 

fabrics, cigarette smolder zone lengths of up to 33 mm were 

observed. Without a cover over the cigarette, the smolder 

region in contact with the substrate often precedes that in 

the center of the cigarette. 

Additional Printcloth Experiments: Salig [44] 

performed a number of other experiments with the printclothipolyurethane foam substrate with thermocouples at 

various locations on and in the substrate. The embedded 

thermocouples were placed 20 mm below the surface of the 

polyurethane foam. In general, ignition did not occur in 

these experiments; however, Salig reported one ignition of 

the polyurethane foam even though the fabric showed little 

evidence of smoldering. This appears to be a rare occurrence, and is mentioned here for the record. 

Figure 5A shows the traces obtained by thermocouples 

located at the fabric surface where it contacts the cigarette 

lying in the crevice. There was only localized charring in the 

fabric and a small cavity in the polyurethane foam, 

indicating that no ignition occurred. The temperatures measured in this manner were about 200°C lower than those 

measured on the cigarette centerline, and the peaks were 

about the same width. 

Figure 5A also shows that temperatures with cigarettes 

covered with the printcloth were somewhat lower, and the 

peaks wider, than those for uncovered cigarettes. (Covered 

substrates have a lower cigarette ignition resistance than 

uncovered substrates, as will be discussed later.) The peak 

temperature measured 20 mm below the cigarette in the 

horizontal polyurethane foam was reported to be 100°C 

higher for the covered than the uncovered cigarette (not 

indicated in the figure). 

(Somewhat different effects of covering cigarettes were 

obtained in another study in which chrornelialumel thermocouples (no size given) were placed at the surface of 

glass fiberboard along, and 25 mm above, and below the 

crevice line [46]. The peak temperatures shown by the eight 

thermocouples for uncovered cigarettes, resting directly on 

the glass fiber board, ranged from 200 to 300°C. and the 

average time above 200°C registered by the eight thermocouples was approximately 20 seconds. With one piece of 

sheeting covering the cigarette, peak temperatures ranged 

from 240 to 35OoC and average time above 200°C was 

again 20 seconds. For two cover sheets, the corresponding 

results were 270 to 35OoC and 30 seconds. It is possible 

that more oxygen was available to cigarettes on glass fiberboard than to those on a fabriclpolyurethane foam 

substrate, and that this. along with the heat containment by 

the cover, accounts for the higher temperatures with cover.) 

Salig's Figures 56 and 5C show temperatures obtained 

with printclothipolyurethane foamicreviceicovered cigarette 

substrates, 20 mm inside the horizontal and vertical polyurethane foam. No ignition occurred. The traces for these 

two locations are similar, with peak temperatures of about 

3OOOC. This is about 150T less than in the fabric, and 

30OoC less than inside the cigarette. 

Figure 5. Timeltemperature 

relationships at fabric surface and 20 

mm inside vertical and horizontal 

PU-Printcloth. 

PrintclothlPUlCrevice. No ignition. 

Cigarette fabric interface 

____- Covered cig. 

- Uncovered cig. 1 

A. 

*' 1 1128 .:.-- '-2, 'Ji '. 

310 2c1; lb ;woo 

Inside vertical PU 

covered cigarette 

4380 - 

3 

256 $ 

CL: 

w 

128 

I 

W 4E 

30 k23ssJ 25 20 15 10 5 0 O Iinside horizontal PU 

covered cigarette 

'. ,&I256 

128 

n " 

30 25 20 15 10 50 

TIME (minutes) 

Figure 6 presents similar traces, but with two cigarettes 

placed end-to-tip into the printclothipolyurethane foam 

crevice. In this configuration. ignition occurred at about the 

time when half of the second cigarette was consumed, 

indicating the importance of time of exposure. At about 40 

minutes after ignition, peaks of approximately 70OoC 

. 

14 
occurred inside the cigarette and of 45OoC 20 mm inside 

the polyurethane foam. The second thermocouple inside the 

horizontal polyurethane foam reached a temperature peak at 

the end of the experiment, indicating, most likely, that the 

smolder wave moved back through incompletely pyrolyzed 

material. Thermocouples 5-7 exhibited the plateau which 

occurs during substrate ignition. 

Other Fabrics: Figures 7 and 8 show temperatures 

inside the cigarette core and the horizontal and vertical polyurethane foam for igniting substrates, both containing the 

relatively heavy duck fabric. Figure 7 shows results for the 

fabric in its "greige" (raw cotton. unscoured) state, Figure 8 

after scouring and bleaching. The greige fabric is expected 

to contain alkali metal ions. primarily Na+ and K'. which are 

known to be smolder promoters [48.52.53]. For the greige 

fabric, the temperature inside the cigarette reached 650% 

Figure 6. Timeltemperature 

relationships inside cigarette core and 

20 mm inside vertical and horizontalPrintcloth. 

Ignition with two cigarettes, end-to-tip. 

PrintclothlPUICrevicel Covered. Ignition. 

Cigarette core 740 

620 

500 

A. 380 

256 

128 

0 

60 55 50 45 40 35 30 25 20 15 10 5 0 

20mm inside vertical PU 

500 

380 

6. 256 

2 

128 .I 5 

oc 

60 55 50 45 40 35 30 25 20 15 10 5 0 

ZOmm inside horizontal PU 

TIME (minutes) 

Figure 7. Timeltemperature 

relationships inside cigarette core and 

20 mm inside horizontal and vertical 

PU-Greige Duck Fabric. 

Greige DucklPUICrevicelCovered. Ignition. 

Cigarette core 7740 

A. ,hf3c 

128 

0 

4c 

45 40 35 30 25 20 15 10 5 0 

Vertical PU 

740 - 

1620 

45 40 35 30 25 20 15 10 5 0 

Horizontal PU - 7.tn . .- 

620 

500 

380 

256 

128 n 

- 

45 40 35 30 25 20 15 10 5 0 

TIME (minutes) 

20 mm inside the vertical polyurethane foam, 500OC. and 

inside the horizontal polyurethane foam, 7OOOC. ihe temper. 

atures observed for the industrially scoured and bleached 

fabric were similar but the peaks were somewhat narrower 

except inside the horizontal polyurethane foam. With many 

of the alkali metal ions supposedly removed by home laundering, the substrate did not ignite, and temperatures inside 

the polyurethane foam stayed below 45OoC (no figure). 

15 
Figure 8. Timeltemperature 

relationships inside cigarette core and 

20 mm inside vertical and horizontal 

PU-Bleached Duck Fabric. 

Bleached DucklPUICrevicelCovered. Ignition. 

A. 

Cigarette core - 740 

- 620 - 

L 

40 35 30 25 20 15 10 5 0 

- Inside vertical PU - .. 

256 2 

128 

B. 

U 

40 35 30 25 20 15 10 5 0 OtInside horizontal PU 

C. 

128 

40 35 30 25 20 15 10 5 0' 

TIME (minutes) 

It is noteworthy that the temperatures inside the horizontal 

polyurethane foam were considerably higher than those 

reached inside the vertical polyurethane foam. Similar observations were made by other investigators [46], who warned 

that reliance on upward char length measured on the fabric 

surface as the passifail criterion, as practiced by UFAC [54]. 

may be misleading. In fact, not only extensive smoldering 

but eventual flaming was reported for horizontal substrates 

which could perhaps be rated "passing" on the basis of the 

upward char length criterion. 

spaced every 20 mm along lines 20 mm inside the vertical 

and horizontal polyurethane foam covered with the bleached 

Figure 9 shows traces obtained from thermocouples 

duck. It seems noteworthy that all'peaks inside the 

horizontal polyurethane foam occurred at almost the same 

time, regardless of the distance from the crevice. The peak 

height decreased with increasing distance from the crevice 

line. In the vertical polyurethane foam, time to peak 

increased with increasing distance from the crevice line. 

Again, the temperatures were higher inside the horizontal 

than inside the vertical polyurethane foam. 

Other Investigators 

In a recent study by Ihrig, et a/., four experimental 

cigarettes were allowed to burn on a variety of substrates 

[19]. The cigarette variables were circumference (21.8 and 

24.8 mm) and packing density (0.15, 0.20, and 0.28 g/cm3); 

the lower values are claimed to be the lower practical limits 

which can be produced. Other variables which may affect 

cigarette ignition propensity (e.g., paper porosity and 

smolder accelerant or decelerant content [5]) were not 

included in this study. The substrates consisted of 33 cellulosic fabrics, ranging from 135 to 775 gim'. which covered 

the range available in local retail stores in 1984. Each fabric 

was used over a polyurethane foam and over cotton batting 

padding, in three configurations, flat, rectangular crevice, 

and acute angle crevice. The fabric ignition temperature, air 

permeability, moisture content, density, and sodium and 

potassium ion contents were determined, as were burn rate 

and heat output characteristics of the four cigarettes. In 

addition. a method was developed to measure the smoldering proclivity of the individual yarns sampled from the 

fabrics. 

Differences in the propensity of the cigarettes to ignite 

We draw the following conclusions from this work: 

was shown on 29 of the 181 substrates. (Some tests were 

not performed due to shortage of fabric.) 

The results indicate that a combination of low diameter 

and low packing density may further decrease the ignition 

propensity of cigarettes. This is in agreement with eariier 

findings on commercial cigarettes (which, however, may 

also have varied in other parameters) [6,7,8,10-131. 

The ignition propensity of the cigarettes was correlated to 

the heat output from the cigarettes, in caloriesicigarette. 

The cigarette ignition resistance of polyurethane foam and 

cotton batting mockups decreased with increasing alkali 

metal ion concentration in the fabrics. Among the polyurethane foam mockups, increasing fabric weight and 

decreasing fabric density also were found to reduce ciga~ 

rette ignition resistance. Most cotton batting crevice 

mockups ignited; among the flat cotton batting mockups, 

cigarette ignition resistance seemed to decrease with 

decreasing fabric weight, perhaps due to the generally 

high alkali metal content of cotton batting which may 

come into play earlier if the fabric is light. 

Over the range studied, cigarette variables were less 

important than fabric or padding variables in predicting 

probability of ignition. 

. 

16 
The smoldering proclivity of the yarns increased with 

increasing alkali metal content of the fabrics This test 

causing the yarn to smolder and observing the distance 

and duration of smolder could perhaps be adopted by 

UFAC or the fabric industry as a simple predictive 

method lor the efficacy 01 final rinsing of fabrics If yarns 

which have been immersed in soft water and dried 

Figure 9. Timeltemperature 

relationships at various locations 

inside vertical and horizontal PU. 

Thermocouples 20 mrn inside PU at various distances 

from crevice line. Bleached DucklPUICrevicelCovered 

Cigarette. Ignition. 

864 

20mm inside vertical PU 

- 

A,i -1;;; 

128 y - 54 

0 u1 

LT 

3 

55 50 45 40 35 30 25 20 15 10 5 0 

G 

4 

U 

W 

20mm inside horizontal PU 864 ?j A, n 1:;: 256 

4 128 

0 

55 50 45 40 35 30 25 20 15 10 5 0 

TIME (minutes) 

smolder less than the yarns tested as taken from the 

fabric, the final rinse probably has not removed the alkali 

metal ions efficientiy and the cigarette ignition resistance 

of the fabric could he improved by further rinsing. 

The total number of ignitions for rectangular and acute 

angle crevice mockups were similar. The rectangular 

configuration is the one chosen for most tests of uphol~ 

stered furniture substrates. 

Most other investigators were interested mainly in 

substrate behavior. with the objective of producing more 

smolderresistant furniture. rather than defining cigaretteisubstrate interaction. One laboratory measured fabric 

surface temperatures with thermocouples in contact with the 

upholstery fabric surface at various distances from a smol~ 

dering cigarette placed on the labric with the coal end 

down [47.48]. In this configuration. both peak temperatures 

and peak widths increased with increasing cotton labric 

weight. The smolder propagation rate measured on the 

fabric surface was inversely related to fabric weight hut the 

mass burning rate remained constant. For a 542 gim” cotton 

fabric, the smolder rate varied from 2.7 mmimin for poly^ 

urethane foam padding to 4.5 mmimin lor glass fiberboard. 

The following paddings produced results within the 3.5 to 

4.0 mmimin range: 25 mm thick polyester batting, polyurethane foam covered with this batling, polyurethane loam 

covered with flame retarded cotton batting. 50 mm thick 

polyester batting, and flame retarded cotton batting. 

by backcoating decreased its smoldering rate by only 14 

percent, and decreased the peak temperature by about 

50°C [48]. (Washing the fabric in distilled water again 

prevented ignition ) Other investigators increased air per me^ 

ability of the cover labric by cutting slits in it [49]. They 

lound that air permeability changed in this manner did not 

affect smoldering temperatures measured at the crevice; 

however, temperature peak width decreased with increasing 

fabric air permeability, Higher temperature peaks and 

narrower peak widths were found for a lighter than an 

heavier fabric: this agrees with Saiig’s results [44]. 

Olsen and Bollinger reported generally higher peak 

temperatures in the crevice with the fabrics over poly^ 

urethane foam than over glass fiberboard [50]. The lowest 

temperatures and the fastest burn rates were lound with 

cigarettes placed in glass fiberboard crevices, without fabric 

cover. When the hoard was covered with fabrics varying in 

weight from 380 to 530 gim”. Olsen found, unlike most 

others, no consistent relationship of temperature and burn 

rate to fabric weight, indicating that fabric finish and other 

factors dominated in this case. In these glass fiberboard 

experiments, covered cigarettes produced higher temper& 

tures and wider peaks than uncovered cigarettes. Filter and 

nonfilter cigarettes of the same brand gave similar results. 

The effect of fabric weight and padding material was 

investigated with thermocouples placed in the crevice and 

above and below it at the fabricipadding interface 01 the 

vertical member of the crevice [46]. The fabric weight was 

varied by using one, two. or three layers of each of two 

cotton fabrics. The padding materials were glass fiberboard. 

polyurethane foam, and cotton batting. With polyurethane 

loam substrates. and when the fabric mass was low, e.g., 

one layer, the initial temperatures were higher below the 

crevice than above it With three layers, the temperatures 

were reported to he higher above the crevice In the case 

of the cotton batting. temperatures above and below the 

crevice were similar. These experiments were apparently 

discontinued when obvious Ignition occurred, so the above 

findings are only for the initial stages of smoldering 

Decreasing the fabric air permeability by a factor of eight 

17 
Figure 10. Arrangement for inducing ignition with an electrical heating coli. 

A. 

All dimensions in millimeters 

B. 

Heating coil 

(8mm dia. x 

40mm long) SECTION A-A 

18 
Ignition by Electric Heating Coils [44,45] 

For research purposes, there has been some interest in 

replacing cigarettes by using better~defined heat sources, 

such as electric heating coils. In this manner, the ignition of 

polyurethane foam and other substrates could he more 

easily modeled. Salig’s attempts in this area are described 

below [44]. 

Figure 10 shows the experimental arrangement: a 40 mm 

long, 6 mm diameter electric heating coil was inserted into 

polyurethane foam blocks covered with fabrics. This is obviously quite different from a cigarette ignition situation hut 

may be appropriate to study smoldering in foam. The 

smolder wave progress was characterized by thermocouples 

embedded inside the polyurethane foam. Figure 11 shows 

the results. A heat flux stated by the author to be about 16 

kW/m2 initiated smoldering: the method of inferring this flux 

is not described. 

With a dyed cotton duck covering the polyurethane foam, 

the smoldering continued for about 50 mm and then ex tin^ 

guished: temperatures at the polyurethane foam center were 

about 380% and considerably lower at the edges. The 

smolder self-extinguished even when the heating coil deliv~ 

ered as much as 30 kWim’. 

When the polyurethane foam was covered with a heavier 

diamond weave cotton fabric. both polyurethane foam and 

fabric smoldered to completion (Figures 12 and 13). Peak 

temperatures inside the polyurethane foam reached 550% 

Figure 11. Timeltemperature relationships inside a fabric-covered PU block, with 

electric heating coil (various output) embedded. 

Dyed DucldPUIFlat. 

B. 

16.5 k Wlrn 4380 

-1 4256 %eu128 T9 20 15 10 5 0 0 

F 

3380 

A. 

13.5 kW/m2 

128 

BO 

M5 

M7 - 0 

ow 20 15 10 5 0 111 

3 

F 

< 

TT 

380 f 

z 256 w 

128 

0 

a:

F 

20 15 10 5 0 

TIME (minutes) 

20 15 10 5 0- 

TIME (minutes) 

19 
and at the top and bottom surfaces, 5OO0C. These peaks 

were first reached at the top, then at the bottom. and only 

then at the center thermocouples. The condition of the 

substrate 18 minutes into the experiment is shown in Figure 

13: Salig stated that the bulging of the fabric ahead of the 

smolder may be due to expansion of the hot, gaseous 

combustion products from the polyurethane foam 

This experiment indicates the importance of a "critical 

fabric weight per unit area" in the polyurethane foam ignition 

process, in this case, with the electric heating coil as the 

ignition source. The same need for a critical fabric weight 

per unit area has been found for cigarette ignition sources, 

as discussed above and in Section 6. It also provides 

insight into the manner in which gaseous combustion 

products move inside fabric covered polyurethane foam. 

On the other hand, the heating coil experiments clearly 

point out the differences between a transient and a steady 

heat source. Thus, the cigarette burn cone with its small 

area does not ignite polyurethane foam without the intermediate smolder front of critical weight per unit area 

(medium to heavy) cellulosic fabrics. The static heating coil, 

with its larger surface, ignited polyurethane foam directly, 

but the continuation of the smolder process again depended 

on the fabric cover ignitability. It is also noteworthy that polyurethane foam smolder was reported to he initiated by a coil 

heat flux of 16 kW/m2 while cigarette total heat fluxes were 

reported to be 40 kW/m2 obviously distributed over a much 

smaller area. While the heating coil experiments are of some 

modeling interest for polyurethane foam ignition, they seem 

to be only of limited relevance for the present purposes. 

Summary of Findings on 

Cigarettelsubstrate Interaction 

No complete model can be constructed from the above 

survey of observations on cigaretteisubstrate interactions 

However, common threads can be found among these 

studies, which vary greatly in methodology and purpose: 

Placing a cigarette on a substrate can significantly lower 

the cigarette temperature and burn rate. These reductions 

seem to be larger for substrates which subsequently 

ignite than for those which smolder along with the cigarette but self-extinguish when the cigarette burns out. For 

example, the peak core temperature of cigarettes burning 

in air was measured to be about 7OO0C, of cigarettes 

burning on substrates which smoldered but selfextinguished, about 6OOOC. and of those measured 

during ignition of the substrate, about 5OO0C. After igni~ 

tion of the substrate, heat appears to be fed back into the 

cigarette, raising the core temperature to 600 to 7OOOC. 

One could question whether the study of the burning of 

cigarettes in air is relevant to their behavior on substrates 

prior to any substrate ignition. Experiments to investigate 

this phenomenon are presently under way as part of the 

work under the Cigarette Safety Act. 

Figure 12- Timeltemperature 

relationships inside a fabric covered 

PU block, with electric heating coil 

(1 5.5 kW/m*) embedded. 

Diamond weave fabric/PU flat. Ignition. 

A. ,&I ~9 T7T5 

25 20 15 10 5 0 

500 

380 

256 

128 

0 

1620 

500 

380 5 

256 E 

a 

z 128 w 

n 

W 

2 

c 

25 20 15 10 5 0" 

1 

500 

380 

256 

B9 128 

0 

C. ,&I 

25 20 15 10 5 0 

TIME (minutes) 

20 
Cigarette core temperatures reach a plateau during smoldering ignition of the substrate; this appears to be due to 

competition of the smoldering fabric for available oxygen. 

Some time after full ignition of the substrate (foam involve 

ment), the cigarette temperature is further increased 

evidently by feedback from the substrate. 

Cigarettes do not ignite most present-day polyurethane 

foam substrates unless they are covered by a smolder^ 

prone fabric. it takes the critical weight per unit area of a 

medium to heavy weight cellulosic or acrylic fabric to 

obtain polyurethane foam ignition. Cotton batting 

smolders readily, with and without cellulosic fabrics. 

In crevice ignitions (with the two members at right 

angles), the temperature inside the horizontal poly^ 

urethane foam generally reaches higher peaks earlier 

than the temperature inside the vertical polyurethane 

foam slab. The temperature traces inside the polyurethane foam show less pronounced plateaus before 

ignition than do the traces obtained at the cigarette core. 

Experiments with electric heating coils placed inside the 

polyurethane foam cannot be substituted for cigarette 

experiments While a Japanese worker developed a "standard cigarette" ignition source consisting of a series of 

small electrical coils heating consecutively, the correlation 

between results obtained with this apparatus and results 

with cigarettes of varying ignition propensity was not 

proven [55]. 

Figure 13. Schematic drawing of smolder wave in fabric covered PU block, with 

electric heating coil (1 5.5 kWlm2) embedded. 

Diamond weave fabric/PUlflat. Ignition 18 minutes after start of experiment. 

0 Thermocouple 

Virgin foam 

0 Char 

t Temperature increasing 

4 Temperature decreasing 

All temperatures in OC 

Slightly stretched fabric 

. I .. 

.. .'. . . . .. .. 

,. s zone 

Char-formation zone .,. . 

,. _ .. 

,1,,,1,11 

Riilninn foam 

'Upholstery fabric :retched fabric I, 

21 
I Substrate Smoldering 

Mechanisms 

- 

This section is a brief review of the literature on smoldering of the major padding materials in upholstered items: 

cellulosic materials and polyurethane foams. While cellulosic 

padding-cotton batting-ignites readily in contact with a 

cigarette (because of its favorable packing density and 

abundance of alkali metal ions), polyurethane foam as 

currently manufactured needs a smoldering cellulosic fabric 

cover before it ignites on exposure to a cigarette. 

The tobacco column and the paper covering a cigarette 

are chosen so they will continue to smolder even if not 

puffed. The paper and tobacco column smolder at the sane 

rate. This smolder spreads readily from cigarettes to 

medium and heavy weight cellulosic and acrylic fabrics and 

from then to many commercial padding materials especially 

cotton batting and polyurethane foam. Certain materials, 

such as thermoplastic fabrics and batting wool fabrics, and 

halogen-containing materials (vinyl-coated fabrics, vinylvinylidene back-coatings, or polyurethane foam with smolder 

resistance (SR) treatment) interfere with this transfer. This will 

be discussed in more detail in Section 6. 

Smoldering of Cellulosic Materials 

There is a wealth of analyses of cigarette (mostly tobacco 

column) smoldering behavior, as discussed earlier, and a 

series of papers analyzing the smoldering behavior of 

shredded cellulose insulation and polyurethane foam [53,56 

591. No model of smoldering of cotton fabric or batting was 

found, but the general degradation behavior of cellulosic 

materials can be approximately described by the following 

simplified overall reaction scheme: 

A. char + vaporsigases 

(absence ut air) '02% 

_lash + gases - 

fuel' 

1,. 

"'\hat + vaporsigases /uz 

The gases and chars produced by the two different paths 

may differ in their chemical nature [56] 

The above diagram shows that initially there are competing 

oxidative and pyrolytic reaction pathways; the oxidative 

pathway can be moderately exothermic (several hundred 

calories per gram of fuel). Both initial pathways nay form a 

high carbon-containing material (char); the two chars are 

probably not identical in reactivity or in other properties. 

These chars are typically somewhat more resistant to oxidation than the initial fuel but ultimately can be completely 

gasified, releasing a few thousand calories per gram of 

char. This second oxidation wave can often be visually 

observed as a glow moving over a previously charred area. 

There appear to be no descriptions of basic smoldering 

experiments with cotton batting or fabrics in the literature. 

However, in experiments involving shredded cellulosic insulation on a heated plate, Smoldering could be initiated at 

temperatures as low as 220%. especially in thick smolder 

beds [57.58]. (This compares with coal temperatures measured in cigarettes between puffs of up to 750°C (Section 

3.1). albeit spread over a much smaller area.) Smoldering 

rate increased with: denser packing of the cellulose insulation, thicker insulation beds, increased oxygen supply, and 

favorable air current direction. Alkali metal ions have been 

shown to be smolder promoters in other types of cellulosic 

materials [48.52,53]. The role of smolder retardants. 

primarily boric acid, is to interfere with the char oxidation 

process; they do not necessarily reduce temperatures in the 

initial smolder wave. 

Smoldering of Flexible Polyurethane Foam 

Few, present~day. commercial polyurethane foam upholstery 

or mattress foams could be expected to smolder in contact 

with burning cigarettes (unless a fabric cover was present) 

even though such foams vary widely in density. air permea~ 

bility. chemical composition. etc., e.g.. [44.60 611. Peak 

smolder temperatures in polyurethane foam were about 

400OC or higher, and smolder front progress in those foams 

which smoldered was about 6 rnmlmin. The overall foam 

degradation process during smolder again can be divided 

into two major competing pathways: formation of nonsmoldering tar and formation of smoldering char. A simplified model of the smoldering process in polyurethane foam 

is given below l62.681: 

. . 

. 
0, depleted 

air air N. Ignition 

or fabric foam 

smolder 

source+Foam- Degraded --Tar-Gas 

(21 (41 

Air (3) 

Air + 

Heat + char 11-Char I 

(5) 

Step (1) 

The first phase of polyurethane foam pyrolysis involves 10~ 

15 percent weight loss. The product is colored but still has 

some of the resiliency of the original foam. 

Steps (2) and (3) 

In the absence of air or when the rate of Step (3) is prohibi~ 

tively slow, the degraded foam is converted to tar with the 

loss of extended surfaceiunit volume essential for smolder. 

In air. char is formed 

Step (4) 

In the absence of air the tar is completely gasified leaving a 

small residue (1~3 percent) at 5OO0C 

Step (5) 

The black cellular char (which retains much of the foam 

structure) formed in Step (3) undergoes further oxidation in 

air and provides heat to drive the smolder wave. If Step (5) 

is sufficiently fast, then the rate of heat production may be 

adequate to replace the outside ignition source so that it 

recedes so far from the external heat source (e.g.. smol~ 

dering fabric or cigarette) that its own heat generation can 

no longer overcome heat losses; it will then extinguish 

Two possible approaches to making polyurethane foam 

smolder resistant have been suggested [63]. One is the use 

of agents which would interfere with Steps 3 and 5. above, 

and, if sufficient volatile agent becomes available, also 

reduce fabric smoldering. The second is promotion of tar 

formation by weakening the polyol chain and urethane links. 

The latter, however, may increase flaming combustion. 

More specific modeling equations for the smoldering of 

polyurethane foam in a simplified configuration and 

reasonable experimental validation are found in 1621 The 

difficulties caused by the fact that smoldering is very incom~ 

plete combustion are discussed. Both conduction and radiation affect the smoldering rate in open structures, such as 

flexible polyurethane foam. Smolder intensity was found to 

be governed by oxygen supply rate, but smoldering can 

proceed at oxygen supply rates as low as 5 percent of the 

stoichiometric rate of oxygen supply to the smolder reaction 

zone. The threshold oxygen concentrations at which self^ 

extinguishment continued smoldering, or transition to flaming 

occurs were established for three polyurethane foams [61]. 

This work was performed with an electrical heating coil 

embedded in the substrate rather than with a cigarette on 

the sample surface. Such embedded heating coils appear to 

give results different from cigarettes. and seam to lead to 

faster transition to flaming than cigarette-induced smoldering 

as discussed earlier [44]. 

Most polyurethane foam formulation variables had little 

effect on smoldering [63]. A report on an interlaboratory test 

to establish reproducibility of results obtained with a sta an^ 

dard polyurethane foam claims that there were no differences between specimens sampled along the length and 

from top to bottom of a polyurethane foam bun (a produc~ 

tion lot) [65]. A significant effect of breathability of the poly^ 

urethane loam was found, and it was suggested that 

samples be flexed before testing, this increases breathability 

and would simulate conditions in actual use. On the other 

hand, experience has shown that it is difficult to produce a 

"standard" foam which, combined with a "standard" fabric, 

gives reproducible ignition or non~ignition results [69]. 

Among the reasons may be that foams are not quality 

controlled with respect to cigarette ignition resistance, but 

rather to obtain approximate uniformity of density and 

resiliency. The formulation of flexible polyurethane foam is 

not considered a precise art. 

Some flame retardants increased others suppressed smol~ 

dering Several studies describe improvement in smoldering 

resistance of fabricipolyurethane foam mockups due to use 

of proprietary smolder and flame retardants. e g.. 

[66~68.72.74] 

23 
I Cigarette Ignition Behavior 

- 

Cigarette Ignition Behavior of 

Soft Furnishings 

The papers discussed in this section reported primarily ignition or non-ignition of the substrates [54.69.108]; papers in 

which timekemperature relationships in the substrate or 

cigarette were explored were discussed earlier [44 511. The 

basic configuration of the mini-mockup shown in Figure 14 

was used in most of the evaluations of upholstered furniture 

substrates discussed in this section. The test methods used 

for the evaluation of the cigarette ignition resistance of soft 

furnishings are listed in Appendix A. 

A discussion of the cigarette ignition behavior of soft 

furnishings is given in Sections 3.1, 3.2 and 5 of [9]. An 

earlier bibliography of papers on cigarette and flame ignition 

of upholstered furniture contains 149 references [75]. Two 

general discussions of cigarette ignition resistance summarize the state of the art up to 1984 [76-771. The results are 

based on experiments with mini-mockups, mockups. or fullscale furniture. No papers on ignition resistance of fabrics or 

padding materials alone are included because there is 

ample literature showing that the ignition behavior of the 

individual mockup components does not provide reliable 

ignition information on the material combinations [22,69]. A 

substantial part of the experimental work on cigarette ignition was performed at the California Bureau of Home 

Furnishings [60.79,80,91-97,1051. A discussion of the rele~ 

vance of bench-scale mockup tests to cigarette ignition 

behavior of full size furniture is part of an ongoing study 

under the Cigarette Safety Act. and will be discussed in a 

future report. 

Table 6 summarizes the findings of many such studies. 

The materials in the table are listed from top to bottom in 

the approximate order of decreasing cigarette ignition resistance. In many cases, there is considerable overlap 

between the characteristics of materials listed near each 

other, depending on such factors as smolder retardant finish 

in fabrics or padding, polyurethane foam variables, alkali 

metal ion content, fabric finish and backcoating. 

good cigareae ignition resistance do not necessarily have 

good small flame ignition resistance and vjce versa. For 

example, substrates covered with thermoplastic fabrics tend 

to resist cigarette ignition because some of the heat transferred to the fabric is absorbed by fabric melting. However, 

It should be emphasized that some materials which have 

Figure 14. Mini-Mockup Test 

Arrangement for Cigarette Ignition. 

Cigarettes are generally placed into the crevice. 

cottoni 

batting 

or glass 

fiberboard 

Machine direction 

Fabric 203x203 

AII aimensions in millimeters \y 

24 
the thermoplastics shrink. curl and melt upon contact with 

an open flame and expose the padding On the other hand, 

cigarettes induce smoldering in medium to heavy weight 

cellulosic fabrics, with consequent heat transfer to the 

padding. but in contact with a small flame cellulosic fabrics 

char and. until the char breaks, protect the padding. Simi~ 

My. some flame retardants for polyurethane foam reduce 

resistance to smoldering, while others improve both flame 

and cigarette ignition behavior [60]. 

To prevent ignition by cigarettes, it is not necessary to use 

only the materials listed on top of each column in table 6. 

For instance. the combination of a light weight thermoplastic 

fabric with polyurethane foam may not ignite. Similarly, the 

combination of a medium weight cellulosic fabric with a 

layer of polyester batting enveloping a polyurethane foam 

slab may not ignite. Many wool and medium~to-heavy PVCcoated fabrics with flame retarded or ordinary polyurethane 

foam or mixed (thermoplasticicellulosic fiber) batting have 

satisfactory cigarette ignition resistance. Material combina~ 

tions which are, for all practical purposes cigarette ignition 

resistant in a crevice configuration with the cigarette covered 

(the worst case conditions). can be chosen on the basis of a 

few trials in a qualified laboratory. The number of such trials 

can be kept small by using the information from the table. 

following discussion will be based. Table 7 compares results 

obtained with a number of fabrics combined with untreated 

and flame retarded polyurethane foam [go] Table 8 summa^ 

rizes two studies by the California Bureau of Home 

Furnishings [91.93]. In one, conducted in 1976 over 80 

upholstery fabrics popular in California at that time were 

tested over 10 padding materials each in the mini~mockup 

Tables 7 and 8 are examples of data on which the 

Heavy thermoplastics 

Celiuloseltherrnoplastics 

blends [depeiiding on 

thermoplastic percentages) 

Light thermoplastics 

configuration. The other study covered 171 commercial 

furniture items sampled in 1981-82 to check compliance 

with the California standard. 

Below is a discussion of the effect of the individual 

substrate components on cigarette ignition. Because of the 

interaction between such components, there is a certain 

amount of redundancy. 

Effect of Fabrics 

Fiber content and weight. Many studies indicate that 

increasing the amount of cellulosic materials (cotton rayon, 

linen, hemp in fabrics. cotton in batling) in the substrate 

decreases cigarette ignition resistance. Increasing the 

amount of thermoplastics (nylon, polyester, and polyolefin in 

fabrics and thermoplastic fibers usually polyester in batting) 

increases the cigarette ignition resistance. 

The highest cigarette ignition resistance is obtained with 

wool and PVC-coated fabrics [22,76.82,90]: their efficacy 

increases with fabric mass per unit area (fabric weight) and. 

in the case of PVC, thickness of coating. Blending of thermoplastic fibers with cellulosic fibers increases cigarette ignition resistance over that of pure cellulosic fabrics; the data 

shown in Table 8 imply that fabrics with 20 to 50 percent 

thermoplastic content rarely ignite from cigarettes [91~96] 

Table 6. Upholstered Furniture Components Listed in Approximate Order of 

Descending Cigarette Ignition Resistance [44-51,54,69-1081 

Resistance Cover Fabrica.b Padding Interliners Welt Cords 

Construction 

-

Parameters ~ - 

Spec ally foams" Alumiriiied labrics Alurn~n~zed Flat areas 

Polyester batting Neoprene sheets PVC Flat areas 

PU Novoloid fells SR treated cellulosics Tuns 

SR cellulos~c batting Thermoplastic iabrics Celllibsics Crevices 

Untreated PU Cellulosic iabrics 

Mixed fiber battirig 

Cellulosic baning 

Vinyl c.oated glass lab Thermoplastics near welt cord 

,'Data on the behavior of acrylic labrics are sparse. bu! ihcse fahrlcs seem to behave more like ccllulos~cs lhan therniiii 

'Fabrics here include woven knitted. and nonwover structures. 

There is probably no effect 01 cellulosic fabric weight when it IS used with cotton batting 

'Includes here neoprene arid combustion modified, high resiliency (CMHR) PU loam 

SR - srnoider resistant 

ilastics 

25 
However, no systematic study of such blends to optimize 

the retention of the appearance and feel of cellulosic fabrics, 

as well as cigarette ignition resistance, has been undertaken. Possible variables in such a study would be: location 

of the thermoplastic fibers-e.g., by placing them in the 

filling in weaves where such filling appears mostly on the 

surface; amounts needed in intimate yarn blends to obtain 

cigarette ignition resistance; type of thermoplastic- nylon, 

olefin, polypropylene, etc. 

Finish: Permanent (non-water-soluble) flame retardant treatments of fabrics do not necessarily increase ciRarette igni~ 

[47,93.98-1031. Higher concentrations are often needed for 

cigarette ignition resistance than for flame resistance. Such 

treatments can affect the color and feel of fabrics but have 

been recommended for batting for prison mattresses, for 

example [47,101]. 

Proprietary spray products claimed to make possible 

reasonable cigarette ignition resistance and flame ignition 

resistance of upholstered items by retrofit have been 

promoted. Tests with three such sprays indicated that the 

needed amount of spray is larger than one would expect a : 

consumer to aDolv. and that it caused the fabrics to amear 

. 

,, ~. ,. 

tion resistance and can, in fact, exacerbate the-smolder 

tendency of cellulosic fabrics [9l]. Treatment of cellulosic 

fabrics and cotton batting with some non-permanent 

materials, e.g., a combination of borax and boric acid. can 

increase both flame and cigarette ignition resistance 

discolored and harsh to the hand [107]. 

Most commerciai backcoatings either did not affect the 

cigarette ignition resistance or else seemed to improve it 

[79,85,91.93.97,106]. A vinyl vinylidene latex backcoating 

and certain organophosphorus flame retardants added to 

the backcoating have been reported to improve furniture 

fabric cigarette ignition resistance [104.106]. 

Table 7. Typical Cigarette Ignition Test Results [go] 

Fabric Fabricb PUC Cigaretted 

Weight Burn Foam Ignition 

Fabric Structure’ Time (s) 3!kE PasslFaIl 

100% cotton chemille 355 13 NFR F 

FR F 

56 cot + visi5pe139 acr 

52 linen148 cot 430 

400 

plush 

panama 

54 nyI132FR vis114 pe 

34 woo1152 visi14 nylon 

65 woo1135 FR vis 

plush 

panama 

twill 

400 

450 

540 

26 NFR 

FR 

41 NFR 

FR 

47 

56 

SE 

NFR 

rR 

NFR 

FR 

NFR 

rR 

P 

P 

F 

F 

P 

P 

P 

P 

P 

P 

52 WOO1127 coti21 nylon 575 SE NFR P 

twill FR P 

100 wool reps 

PVA PVC twill 

375 

475 

SE 

SE 

NFR 

FR 

NFR 

FR 

P 

P 

87 cot113 FR VIS zoo SE NFR F 

FR P 

’cot - cotton, vis - viscose, acr ~ acrylic, pe ~ polyester 

‘,Modified CS-191 Test (flame ignition), SE - selfbextinguishlng 

‘.PU untreated (NFR) 30 kgim3, flame retarded (FR) 33 kg1mJ 

“F - fail, P - pass 

26 
Contamination of cellulosic fabrics and battings. The 

presence of alkali metal ions, such as sodium and potassium. decreases cigarette ignition resistance [19.48.52,53]. 

This important effect has thus far hardly been considered by 

industry in fabric design and finishing. 

Alkali metal ions are always present in unscoured cotton. 

On finished fabrics, they may be present as residual detergents, softeners, dyes, or dye auxiliaries. Rinsing such 

fabrics in clean water or laundering often causes dramatic 

improvements in cigareae ignition resistance [19,45.48,52] 

In spite of the publication of these results little seems to he 

done by industry to remove these contaminants. A simple 

method to evaluate whether residual fabric finish lowers the 

cigarette ignition resistance of fabrics is described in Section 

3.2.2 [19]. 

Since perspiration and other dirt likely to be deposited on 

soft furnishings contain alkali metal ions furniture may 

become more ignitable with age. However a study of the 

effect of use and aging on the cigarette ignition resistance 

of chair cushions is not conclusive on this point [84]. 

Tension. No systematic study of the effect of fabric 

tension on cigarette ignition resistance is available, but a 

summary of personal observations from our laboratories can 

be reported. When tension is low, as in old furniture or 

certain styles, air layers may form between the fabric and 

the padding, and cigarette ignition will be determined 

entirely by the fabric. With higher tension, intimate contact 

between the fabric and padding is achieved and the 

padding can act either as a heat sink (e.g , smolder resis~ 

tant polyurethane foam). absorb heat during melting poly^ 

ester hatting), or smolder along with smoldering fabrics 

(cellulosic batting). 

Miscellaneous construction factors. The effect of fabric 

weight has already been discussed. No systematic studies 

of the effect of other fabric parameters, such as weave, yarn 

size and density, pile vs non-pile. etc., have been carried 

out. In grass clippings and foam, denser packing has been 

shown to increase the smolder tendency [16.17,61.109] 

This indicates that not only weight hut dense packing of 

fibers and other cellulosic materials proniotes smoldering 

Lowering air permeability has been reported to increase 

cigarette ignition resistance, hut in some of these experi~ 

ments. this was achieved by applying latex backcoatings 

This process introduces extraneous materials and increases 

the weight [48] Increasing the air permeability by making 

slits in the fabric increased the smoldering rate, but not the 

smoldering temperature and total char areas (491 

Sheets and blankets can increase the probability of 

mattress ignition when they are placed on the top of a 

burning cigarette. These items generally do not ignite from 

cigarettes (22,821. 

Effect of Padding Material 

The relative effect of padding material on cigarette ignition 

resistance is summarized in Table 6. Smolder resistant 

neoprene and the combustion modified. high resiliency 

(CMHR) polyurethane foams rank high. Polyester batting 

absorbs heat as it melts. Many flame retarded treatments of 

polyurethane foam used some years ago did little to 

improve smolder resistance or even reduced it. In the last 

few years, mainly in response to the California requirements 

[1 lo]. flame retardant treatments which improve both 

smolder and flame resistance of polyurethane foam have 

been marketed. The smolder resistance of the boric acid 

treated cotton hatting depends on the boric acid concentra~ 

tion; some of this can be lost in handling the batting since 

the material does not stick well to the fibers [102,103]. 

Untreated cellulosic batting smolders readily 

[22.54,60,69~71,88-101,1 IO]. 

Effect of lnterliner or Barrier Materials 

The UFAC program (541 requires that all cover fabrics he 

tested, and those which are more ignition prone (called 

Class II by UFAC) must he used with a harrier material. The 

most common barrier material is polyester batting. However, 

many fabrics. especially heavy cellulosics, ignite even with 

such polyester harriers [69,79] On the other hand, the use 

of aluminized barrier or interliner materials between the 

cover fabric and padding was found to be very effective in 

increasing cigarette ignition resistance 122.44.45.71 1 

UFAC also introduced a test for "interior fabrics." fabrics 

often placed between the cover fabric and the padding [54], 

The test generally fails cellulosic fabrics hut passes ther~ 

moplastic woven and nonwoven fabrics. Other interliners 

which increase cigarette ignition resistance are neoprene 

and CMHR polyurethane foam sheets. 

Effect of Welt Cord 

The cigarette ignition resistance of crevices and cushion 

edges can he enhanced or reduced by the presence of a 

welt cord. depending on its type [54.69-711. The cigarette 

ignition resistance is reduced if the welt cord contains a 

cellulosic material. usually in the form of twisted paper or 

cotton cords. Aluminum foil twisted into welt cords has been 

shown to have better cigarette ignition resistance than 

untreated and flame retarded cellulosic welt cords (781. 

UFAC has recently upgraded its welt cord standard to elimi~ 

nate the latter 154). Some thermoplastic and PVC welt cords 

also conform to the upgraded welt cord standard. 

In addition to the direct effect of the welt cord. it is often 

enclosed in a strip of fabric. This increases the fabric mass 

in the crevice. In the case of cellulosic fabrics. this reduces 

cigarette ignition resistance. and in the case of ther~ 

moplastics, it may increase it [54.69] 

Effect of Furniture Geometry 

For any combination of fabric and padding material. ciga~ 

rette ignition resistance is better in the flat areas than in the 

crevices [6,19.23,44.45.69,77]. Several factors may 

contribute to the greater hazard in the crevice' re~radiation 

of heat from two, rather than one, surfaces; a chimney effect 

in the crevice under the cigarette (22,441; and, in the case 

27 
Table 8. Cigarette Ignition Resistance of Typical FabriclPadding material 

Combinations [91-921 

Percent of Fabrics Igniting 

A. Mini-mockup results (1977) 

padding materials' 

Batting: 

100% cotton 

Untreated 

FR treated 

70/30 cotton/polyestei 

100% polyester 

Non-resinated 

Resinated 

Polyurethane 

Untreated 

FR treated 1 

FR treated 2 

High resiliency 

Foam: 

Neoprene interliner over cotton 

batting 

Glass fiberboard 

B. Results on 171 furniture items 

(1983) [225Ib 

fabric weight 

fabric weight 

100% 

Cellulosics 

100 

76 

79 

33 

19 

41 

86 

38 

83 

19 

100 

< 270 girn': 67 

2 270 g/rn2: 95 

Cellulosic/ 

Thermoplastic Blends 

82 

43 

32 

7 

4 

25 

54 

25 

57 

14 

54 

270% cell: 6 

< 70% cell: a2 

100% 

Thermoplastic 

9 

0 

0 

0 

0 

0 

0 

0 

0 

0 

0 

6 

'Filling material specifications 

Materials 

1. Batting: 

100% cotton, untreated 

FR cotton (12.15% boric acid) 

70/30 cotton polyester, bonded 

100% polyester, resinated (28% acrylic resin) 

100% polyester, non-resinated (with polyester scrim) 

2. Foam: 

Untreated PU 

FR PU 1 (antimony trioxide and PVC) 

FR PU 2 (brominated biphenyl) 

High resiliency PU (brominated organophosphate) 

3. Neoprene interliner: 5 mm thick with cotton scrim backing 

Warious filling materials 

Density, kg/m3 

38 

38 

37 

8 

8 

20 

37 

32 

42 

950 g/m2 

2a 
of cellulosic fabrics, an increase in the mass of cellulose 

because of multiple seams at pillow edges. Crevices can be 

rectangular, or, if the top of the cushion is rounded or 

pulled away from the vertical surface. form an acute angle. 

Ihrig. et ai., have shown that there is little. if any, differeance 

in the cigarette ignition resistance of these two crevice 

configurations [19]. Tufted areas also tend to have lower 

cigarette ignition resistance than flat areas and are usually 

tested separately. as are areas near the welt cord of flat 

cushions [22]. 

Cigarette Ignition Behavior of Wildlife Materials 

Some of the early investigations of the propensity of 

cigarettes to ignite materials were conducted on wildlife 

materials. The effect of wind velocity and direction and of 

the ambient conditions was also more intensely studied on 

these materials than on soft furnishings. A summary of these 

studies is presented because of the physical similarity of the 

ignition process and the cellulosic nature of the wildlife fuels. 

grass, and punk wood can be ignited by cigarettes 

[16.17,23,25,109.11 11. Conditions which increase the probability of such ignition are: dense packing of material (e.g., 

100 kglm' for dried grass clippings), high ambient temperature and low humidity, and modest winds. Especially in the 

direction of the burn cone travel on the cigarette. Especially 

in winds of 4.8~6.4 kmihr. these substrates seem to burst 

into flames rather rapidly, without lengthy smoldering 

periods. The optimum wind velocity for ignition by cigars 

was higher. about 12 kmihr. 

In the late 192Os, the National Bureau of Standards 

conducted an investigation (in response to Congressional 

interest in reducing cigarette-initiated wildlife fires) into the 

feasibility of reducing the ignition propensity of cigarettes 

[16,17]. A frequency distribution of the length of discarded 

cigarette butts was established. The most frequent length 

was 33 mm, and two thirds of the butts were under 38 mm. 

It was concluded that if cigarettes could be treated so as to 

not ignite substrates while burning over this length. the 

problem would be solved. A number of treatments were 

suggested, including borax, boraxiboric acid, and sodium 

silicate, as well as additional layers of paper or cork at the 

butt end; the latter appeared promising Fortunately. the use 

of asbestos paper for this purpose was shown to be 

ineffective 

Wildlife material, including compacted conifer needles, 

Cigarette Ignition of Garments 

Garment iires are often blamed on cigarette ignitiori 

However two investigators established that the fabrics used 

in such items generally do not ignite from exposure to 

cigarettes [26 1121 Improperly used matches or lighters are 

more likely ignition sources in such cases 

29 
I Relative ignition Propensity 

of Cigarettes 

- 

A number of laboratories have conducted experiments to 

determine the relative ignition propensity of commercial 

cigarette packings [5,7.8,10-17). Several packings with a 

somewhat lower ignition propensity than most others were 

identified in the U.S. as well as Japan. Such identification 

can be made on substrates which have borderline cigarette 

ignition resistance, e.g.. crevices formed by the California or 

UFAC standard fabric and UFAC standard or similar polyurethane foam types [I 1.13). The majority of upholstery 

substrates would, however, either not ignite with any or 

ignite with all commercial cigarette packings, because of the 

small range of ignition propensity of present, commercial 

cigarette packings. 

fabric ignited with all test cigarettes one fabric with none 

and several with some but not all cigarette packings, 

allowing a ranking of the ignition propensity of the cigarettes 

The same cigarette packings were also placed for I, 2. or 

more minutes on flat areas of the substrates of varying cigarette ignition resistance and then removed [7]. If the 

substrate still smoldered 10 minutes after the removal of the 

cigarette. ignition was recorded. Thus the propensity of 

cigarettes to ignite substrates could be defined both by the 

number of substrates a given cigarette ignited and the time 

it took to ignite any specific substrate. Times to ignition 

varied from 2 to 7 minutes; Salig found ignition times of 1.5 

minutes for low cigarette ignition resistance substrates 1441. 

Two means of quantifying the propensity of cigarettes to 

ignite substrates have been suggested. One is to place the 

cigarettes on mini-mockups made from standard fabric and 

foam as in the California upholstered furniture test [110] 

(Figure 2). and measure the mass loss rate. The other 

consists of placing the cigarette on a piece of a~cellulose 

chromatographic analysis paper and again measuring the 

mass loss rate 171. The latter method was proposed in the 

belief that the chromatography paper was more reproducible than fabric and polyurethane foam which have shown 

cigarette ignition resistance variations even in so-called 

"standard materials [69]. This concept was critically 

discussed in [113]. Ihrig. et ai., found a positive correlation 

between cigarette ignition propensity of four experimental 

cigarettes and calicigarette of the cigarettes in air [19], 

In one study, a number of fabrics were used so that one 

VI. 

The studies of relative ignition propensity of commercial 

cigarette packings can be summarized as follows: 

1. Most cigarette packings investigated have similar ignition 

propensity. However, a few packings have been found to 

have somewhat lower ignition propensity. This was found 

for a variety of upholstered substrates, in flat areas and 

crevices varying in fabrics and padding materials 

[6.7.10.11.13-151. in mattresses (8,121, and in wildlife 

material [7.16.17]. 

2. Propensity to ignite did not correlate with burning rate or 

burn cone temperatures of the cigarettes [7]. 

3. While the commercially available cigarettes did not make 

it possible to conduct an experiment in which such 

parameters were varied systematically, it appears that 

lowering the fuel content, by reducing packing density 

and by reducing the diameter may lower the ignition 

propensity [6,7]. Making the burn time of cigarettes 

shorter, by either making the tobacco column shorter or 

lowering the packing density (which increases linear burn 

rate) would obviously reduce the time during which a 

smoker mav become deem and inadvertentlv drov the 

cigarette. 

4. The differences in ignition propensity of the commercial 

cigarette packings tested are small in the context of the 

cigarette ignition resistance of the total population of soft 

furnishings in American homes which may be subject to 

contact with inadvertently dropped cigarettes. Perhaps 

one half of this population-a rough guess indeed-may 

not ignite from any cigarette. This would include 

mattresses produced since 1973, when the U.S mattress 

standard started to be enforced [l14], as well as most 

furniture made to the principles outlined above in Section 

6. Another large portion may ignite with all commercially 

available cigarettes. The percentage of soft furnishing 

substrates which ignites with some but not all present 

day commercial cigarette packings is probably quite low. 

. 

. 

30 
I Conclusions 

- 

ltie literature pertinent to ignition of soft furnishings and of 

wildlife materials by smoldering cigarettes was critically 

reviewed. with the oblective of presenting as much background material as possible which may assist in the 

consideration of cigarettes with lower ignition propensity 

Material was included in this report which may be relevant 

to construction of a model for cigarette ignition of soft 

furnishings. especially information on the burning behavior 

of cigarettes. 

Other material included discusses the cigarette ignition 

resistance of upholstered furniture and mattresses. While 

there is a large amount of literature in those two fields. the 

area of most direct interest- how cigarette parameters affect 

their ignition propensity- had not been well~studied, and 

much more needs to be done. 

Perhaps the most important finding was that the smol~ 

dering behavior of cigarettes on substrates is different from 

that of cigarettes burning in air Compared to the tempera^ 

tures observed in free burning (in air). core temperatures of 

cigarettes before full ignition of fabric and polyurethane 

foam ignition were distinctly lower However, these temperatures were maintained over longer periods. After both the 

cellulosic cover fabric and the polyurethane foam padding 

ignited, heat feedback from the smoldering substrate 

increased the observed cigarette core temperature. 

Studies of the interaction of cigarettes and igniting 

substrates have been performed with commercial cigarettes. 

It was found that most of the cigarettes used in these 

experiments behaved quite similarly. however. a few ciga~ 

rette packings with somewhat lower ignition propensity on 

certain fabricipadding combinations were found in these 

studies. The specific factors which led to the lower ignition 

propensity have not yet been clearly established. 

31 
- 

Acknowledgements 

Dr. Richard G. Gann made numerous helpful suggestions 

and Ms. Paula Garrett skillfully processed this manuscript. 

The patents listed in Appendix B were provided by Drs. 

P. H. Leake of the American Tobacco Co., and A. W. 

Spears, 111, of Lorillard. Richard Harris of the Center for Fire 

Research compiled Appendix B. Ms. Nora Jason of the 

Center for Fire Research performed the data base searches, 

and Dr. Peter Roussopoulos. Forest Fire and Atmospheric 

Research, U.S. Department of Agriculture, arranged a 

search of the USDA reports. 
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- 

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Conference, 120-131, New Orleans, LA (1975). 

McCarter. R.J.. Smoldering Combustion of Cotton 

and Rayon, J. Consumer Product Flammability, 4, 

346-358 (1977). 
1581 

I631 

(641 

Shafizadeh, F,, Bradbury, A.G.W., deGroot. W F. 

and Aanerud, T.W.. Role of Inorganic Additives in 

the Smoldering Cornbustion of Cotton Cellulose, 

Industrial and Engineering Chemistry, Product 

Research and Development 21, 97~101 (1982). 

Important Information from UFAC (Test Methods), 

Upholstered Furniture Action Council. High Point. 

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Suga. S.. Simulated Cigarette Test. Report to the 

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( 1984) 

Ohlemiller, T.J.. Modeling of Smoldering comb us^ 

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Rogers, F E and Ohlemiller, I.J., Cellulosic lnsulation Material I. Overall Degradation Kinetics and 

Reaction Heats, Combustion Science and Technology, 24, 129-137 (1980). II. Effect of Additives 

on Smolder Characteristics 39-52, Ill. Effects of 

Heat Flow Geometry on Smolder Initiation, 26. 89~ 

Ohlemiller. T.J. and Lucca, T A., An Experimental 

Comparison of Forward and Reverse Smolder 

Propagation in Permeable Fuel Beds, Combustion 

and Flame, 54. 131~147 (1983). 

Shafizadeh. F. and Bradbury, A.G.W., Smoldering 

Combustion of Cellulosic Materials, Journal of 

Thermal Insulation, 2, 153 (1979). 

Damant, G.H., Cigarette Induced Smoldering of 

Uncovered Flexible Polyurethane Foams. J 

Consumer Product Flammability 2. 140~153 (1975). 

Ortir~Molina, M.G.. Toong. TY., Moussa. N.A. and 

Tesoro. G.C.. Smoldering Combustion of Flexible 

Polyurethane Foams and Its Transition to Flaming 

or Extinguishment, pp, 1191-1200 in 17th Sympo~ 

sium (International) on Combustion, The comb us^ 

tion Institute, Pittsburgh (1978). 

Ohlemiller, T.J., Bellan. J, and Rogers, FA, A 

Model of Smoldering Combustion Applied to flex^ 

ible Polyurethane Foams, Combustion and Flame 

36, 197~215 (1979). 

Rogers, F.E., Ohlemiller. T J , Kurtz A,. and 

Summerfield, M., Studies of the Smoldering 

Combustion of Flexible Polyurethane Materials, J. 

Fire and Flammability. 9, 513 (1978). 

Ohlemiller, T.J. and Rogers, F.E., A Survey of 

Several Factors Influencing Smoldering Cornbustion 

in Flexible and Rigid Polymer Foams, J. Fire and 

Flammability. 9,, 489-509 (1978). 

Toner, H P , Ignition of FoamiFabric Composites in 

Residential Upholstered Furniture, .I Consumer 

Product Flammability. 9,8594 (1 982). 

Tesoro, G.C.. The Fire Safety of Upholstered Furni~ 

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Potential Improvements, J. Consumer Product 

Flammability. 8, 132~143 (1981) 

105 (1981). 

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Evaluations of the Fire Performance of Flame 

Retarded Flexible Polyurethane Foams in an Upholstered Furniture Application. J. Consumer Product 

Flammability, 7, 99.126 (1980). 

Eicher. W.J. and Srabat. J.F , Response of poly^ 

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Consumer Product Flammability. 7, 172~188 (1980). 

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Reference 41 Fairall, P., Relationship of Small 

Scale Testing to Full Scale Furniture Pertormance. 

U.S Consumer Product Safety Commission (1981) 

1701 Briefing Paper on Upholstered Furniture Flamma 

bility lab B Fairall. P , Analysis of CPSC 40 Chair 

lest Program: Stafford G. and Scharff, D. Uphol~ 

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bility Test Methods and Data Summary. U S. 

Consumer Product Safety Cornmission (1 984). 

Package, Reference 19 Fairall. P., Analysis of 

Upholstered Furniture Test Program, U.S. 

Consumer Product Safety Cornmission (1983) 

[72] S2abat.J F.. Combustibility Aspects of Polyuretharie 

Foams for Mattresses J Consumer Product Flam~ 

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Keating. J Z.. Use of Hydrated Alumina as a Flame 

and Smoke Suppressant Filler for Flexible Urethane 

Foams J Fire Retardant Chemistry. 9, 215~220 

(Nov. 1982). 

Schuhmann. J G , Improved Furniture and Mattress 

Fire Safety Through the Use of Combustion 

Modifying Foam Proc of 6th International SPI 

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1751 Damant. G H , A Bibliography of Published lnforma~ 

tion on Furniture Flammability. J, Consumer 

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Part II, 7, 127~129 (1980); Part Ill (coauthor: 

Wortman, P.S.), 8, 235-238 (1981). 

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182) Fire Research Station Borehamwood. England 

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Damant, G.H.. Williams, S.S. and Krasny. J.F 

Cigarette Ignition Behavior of Commercial Uphol~ 

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Damant, G H,, California Upholstered Furniture 

Combustibility Standard. 1981 Update, J 

[68] 

[69] Upholstered Furniture Flammability Briefing 

1711 Upholstered Furniture Flammability Briefing 

I731 

1741 

1761 

[77] 

(781 

[79] 

1801 

35 
I811 

1821 

I831 

[E41 

I851 

1861 

I871 

1881 

1891 

1901 

1911 

1921 

Consumer Product Flammability, 8, 209~220 (1981). 

A: Ingham, P.E.. Goddard. J.M. and Grueber, A.L., 

The Influence of Fabric Coverings on the Flammability of Polyurethane Upholstered Furniture (1979): 

B: Ingham. P.E., The Flammability of Polyurethane 

Upholstered Furniture, Part II. Tests with Larger 

Ignition Sources and "Improved Foams (1981); C: 

Ingham. P.E.. The Flammability of Polyurethane 

Upholstered Furniture, Part 111, House Fire Tests 

(1981) Wool Research Organization of Naw 

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Pakkala, L.. lgnitability of Beds and Bedding, 

Research Report No. 247, Technical Research 

Center of Finland, Espoo, Finland (1984). 

Ramsay. G.C. and Cerra A.P., A Progress Report 

on the Assessment of Test Methods for the Ignitability of Upholstery Combinations by Small Ignition 

Sources- Cigarette Ignition. lSOiTCl36 document 

(April 1982). 

Harabin, D.. Ostrander, E.R.. and Stout, E.E., 

Properties of Textile Upholstery Fabrics and Their 

Importance to Consumer Satisfaction, (Bulletin 

1032). Cornell University Agricultural Experiment 

Station, Ithaca, NY (May 1973). 

Fesman, G.. A Study in Smoldering Test Behavior 

Versus Air Flow Variations in Fabric. p. 303-307 in 

Proc. of the 6th International SPI TechnicaliMarketing Conference (Nov 1983). 

Gill, J.T.. Howerton, R.D., and Werner, P.M., 

Combustion Acceleration as a Measure of Upholstery Fabric Flammability, Textile Chemist and 

Colorist 13, 3-33 (1981). 

Baitinger. W.F. and Konopasek, L., Smoldering 

Combustion of Cotton FabriciUrethane Foam 

Composites, in Proc. of the 7th International Conference on Fire Safety, 11-22. Stanford Research Institute, Menlo Park, CA (1982). 

Braun, E., Krasny, J.F., Peacock, R.C., Paabo. M.. 

Smith, G.F., and Stolte. A,. Cigarette Ignition of 

Upholstered Chairs, J. of Consumer Product Flammability, 9. 167-183 (1982). 

Hafer, C.A. and Yuill. C.H.. Characterization of 

Bedding and Upholstery Fires, Southwest Research 

Institute, San Antonio, TX (1970). 

Pakkala. L., Kortekallio, E.L. and Ulmanen. M., 

lgnitability of Upholstered Furniture, Nordtest 

Project 186-79, VTT Research Note 6911982, Technical Research Center of Finland, Espoo. Finland 

(1982). 

Damant. G.H. and Young, M.A., Smoldering 

Characteristic of Fabrics Used as Upholstered 

Furniture Coverings. J. Consumer Product Flammability. 4, 60-113 (1977). 

Damant. G.H. and Young, M.A., Flammability Classification of Fabrics Used as Upholstered Furniture 

Coverinqs, J. Consumer Product Flammability, 4 

329~34<(1977). 

Damant. ~~ ~ ,~ G.H.. , Williams S.S. and McCormack. J.A 

The Role of Fabric in the Cigarette Ignition of 

Upholstered Furniture (Laboratory Report No. SP83-2) Bureau of Home Furnishings, Department of 

Consumer Affairs, North Highlands, CA (1983). 

Damant. G.H., McCormack, J.A. and Williams, S.S.. 

California Enforcement Tests on Commercial Chairs, 

Proc. of the 7th International Conference of Fire 

Safety, 2-1 0. Stanford Research Institute. Menlo 

Park, CA (Jan 1982) 

Damant, G H , Home Furnishings Fire Retardant 

Reouirements The California Exoerience. J 

Consumer Product Flammability,' 6. 95-104 (1979). 

McCormack, J.A., Damant, G.H. and Williams S.S., 

Cigarette Evaluation of 450 Pieces of Residential 

Furniture. California Bureau of Home Furnishings, 

North Highlands, CA (1985). 

Williams, S.S. and Damant. G. H., Rate of Weight 

Loss as an Aid to Evaluate the Smoldering prop en^ 

sity of Upholstered Fabrics, J. Consumer Product 

Flammability, 8, 89.104 (1 981). 

Baitinger. W.F., Fire Retardance Treatment of 

Fabrics for the '80s; Smolder Resistant Cotton 

Treated with Boric Acid, Textile Research J.. 52, 

82-86 (1982). 

KnoeDfler. ,~ ~. N.B.. Neumever. J.P. and Madasci. J.P. 

Meeting the Mattress Flammability Standard FF 4- 

72 with Boron Treated Cotton Batting Products. J. 

Consumer Product Flammability. 1, 240-264 (1974). 

Madasci, J.P. and Knoepfler. N.B.. Upgrading Clas~ 

sification of Upholstery Fabrics via Vapor-Phase 

Deposition of Boric Acid, Textile Research J. 49, 

176.190 (1979). 

Verburg. G.B. and Lambert, A.H., SmolderResistant, Oil- and Water-Repellent Cotton Upholstery Fabrics. J. Fire Retardant Chemistry, 7, 136~ 

153 (1980). 

Madasci, J.P. and Neumeyer. J.P.. A Comparison 

of Smolder Resistance Standards for Boric Acid 

Treated Cotton Battings. J. Consumer Product 

Flammability, 9, 3~10 (1982). 

Madasci. J.P. and Neumeyer, J.P., Chemical Additives to the Boric Acid Treatment of Cotton Filling 

Materials Used in Mattress and Upholstered Furniture, J. of Fire Retardant Chemistry, 9, 70-839 

(1 982). 

Leitner. G.J., Reactive Organophosporus Additives 

as Smolder Retardant Agents in Furniture Fabric 

Backcoatings. J. Consumer Product Flammability. 

8, 158.168 (1981). 

Williams, S.S. and Damant. G.H.. Evaluation of 

Three Methods of Rendering Upholstery Fabrics 

Smolder Resistant, Laboratory Report No. SP-82-2 

Bureau of Home Furnishings, North Highlands, CA 

(1 982). 

Knoepfler, N.B., Neumeyer. J.P. and Koenig. P.A., 

Backcoated Mattress Tickings as a Factor in 

Meeting Mattress Flammability Standard FF 4-72, 

Part I. Polymer Backcoating. J. Fire & Flammability, 

Consumer Product Flammability Supplement, 2, 70- 

. 

. 

36 
83 1575). Part 11. Compound Polymer Backcoating. 

2, 123-139 (1975). 

Krasny. J.F.. Evaluation of the Effectiveness of 

Retrofit Products for Increasing the Cigarette lgni~ 

tion Resistance of Upholstered Furniture. NBS 

Letter to the U. S. Consumer Product Safety 

Commission (1984). 

Palmer. K.N.. Paul K T and Taylor, W.. Test 

Specifications for Fire Properties of Bedding and 

Upholstered Furniture, Building Research Establishment Report (ISBN 0 11670663) Her Majesty's 

Stationery Office, London (1979). 

Countryman, C.M.. Ignition of Grass Fuels by 

Cigarettes, Fire Management Notes, 44:3 (1983). 

State of California, Department of Consumer Affairs, 

Bureau of Home Furnishings. Flammability lnforma~ 

tion Package, North Highlands, CA (1983) 

Blackmarr. W.H.. Moisture Content Influences 

lgnitability. USDA Forest Service Research Note SE173. Southeastern Forest Experiment Station, 

Asheville. NC (1972). 

Blackenbaker, S., Cigarettes and Electric Heating 

Elements as Ignition Sources. Proceedings of the 

Thirteenth Annual Meeting. Information Council on 

Fahrlc Flammability, Atlanta, GA (1 979). 

Tesoro. G.C.. Some Reflections on a Proposed Test 

Relating to Ignition Hazard in Upholstered Furniture. 

Textile Chemist and Colorist. 15. 40~44, (April 

1583). 

Code of Federal Regulations. Part 1632, Standard 

for the Flammability of Mattresses (and Mattress 

Pads). FF 4-72 (1983) 

Leake, P.H., American Tobacco Co.. Presentation 

to the Technical Study Group of the Cigarette 

Safety Act of 1984 (1985). 

37 
Appendix A 

Test Methods for Determining I Cigarette Ignition Resistance of 

Soft Furnishings 

D 

Code of Federal Regulations, Part 1633. Proposed Standards for the Flammability (Cigarette Ignition of Upholstered 

Furniture (PFF 6-81), U.S. Consumer Product Safety Commission (1981). 

Important Consumer Information from UFAC, Upoholstered 

Furniture Action Council, High Point, NC (1985). 

The Business and Institutional Furniture Manufacturer's Association First Generation Voluntary Upholstered Furniture 

Flammability Standard for Business and Institutional Markets, 

BIFMA, Grand Rapids (1984). 

Flammability Information Package, State of California, 

Department of Consumer Affairs, Bureau of Home Furnishings, North Highlands, CA (1983). 

Standard Methods of Tests and Classification System of Cigarette Ignition Resistance of Components of Upholstered 

Furniture. (NFPA 260 A) 1986 Standard Method of Test for 

Determining Resistance of Mock-up Upholstered Furniture 

Material Assemblies to Ignition by Smoldering Ciragettes 

(NFPA 260 B). National Fire Protection Association (NFPA) 

(1983). 

Fire Tests for Furniture, Part 1 ., Methods of Test for the lgnitability by Smoker's Materials of Upholstered Composites 

for Seating by Flaming Sources (1982). British Standard BS 

5852, British Standards Institution, London. 

The Upholstered Furniture (Safely) (Amendment) regula^ 

tions, 1983, No. 519, Consumer Protection. Her Majesty's 

Stationery Office, London (1983). 

Upholstered Furniture-Burning Behavior-lgnitability of Upholstered Composites Methods of Test, Part 1. Smokers Materials. Section 1, Cigarette, Section 2, Small Flame 1, Part 3, 

Ignition Sources, Butane Flames, Part 4, Larger Ignition 

Sources (ISOITC136iSClIWG4) Publ. by British Standards 

Institution, Manchester, England (1 982). 

Draft Australian Standard Method of Test for the lgnitability 

of Upholstered Seating (DR 80 123) North Sidney, N.S.W. 

(1980). Method of Test for the lgnitability of Upholstered 

Seating of the Low Fire Hazard Type (DR 80-124) Standards 

Association of Australia, North Sidney, N.S.W. (1980). 

Austrian Standard 5410-A 1606, Part I. Specification for Furniture: Testing Inflammability of furniture Surfaces. Oesterreichisches Normungungsinstitut. Vienna, Austria. 

Irish Standard Specification, Requirement for Smolder and 

Flame Resistant Upholstery, I.S. 244; 1980, Institute for Industrial Research and Standards, Dublin (1980) 

Nordtest Fire 014, NordTest. SF 00340, Helsingfors 34, Finland. 

Furniture Upholstered Seating Method of Test for the Ignitability (by a Smoldering Cigarette), Svensk Standard SS 83 

91 30, SIS Standardiseringgrupp, Stockholm Sweden. 

DOEiPSA Fire Retardant Specification, No. 3: Fire Barrier 

Standards for Upholstery (Seating and Bedding): No. 4: 

(Composite Upholstery Ignition Standard (Seating and Bedding); No. 5: Flammability of Beds and Bedding: No. 6: lgnition Standard for Seating. Department of the EnvironmenUPublic Service Agency, London (Apr. 1978). 

Code of Federal Regulations, 16 CFR, Part 1632, Standard 

for the Flammability of Mattress (and Mattress Pads), FF 4- 

72 (1983). 

Method of Test for the Combustion Resistance of Mattress; 

Cigarette Test. Canadian Government Specification Board, 

Ottawa, Ont. Canada, No. 27.7 (1977). 

Behavior of mattresses in Fire: Cigarette Test. Bulletin official 

des Services des Prix. Annexe a la Recommendation No. 

D1-78 Direction General de la Concurrence et de la Confirmation, Paris Dec. 1978). 

38 
Appendix B 

List of Patents 

- 

A. U.S. PATENTS 

Number 

253,841 

1,020,864 

1,211,071 

1,517,142 

1.555.320 

1,581,451 

1,605,059 

1,666,062 

1.726.737 

1,744,615 

1,770,616 

1,798,537 

1,821,159 

1.879.128 

1,905,416 

1,996,002 

1,999,222 

2,013,508 

101,312 

2,049,320 

2,098,619 

2,134,213 

2,147,889 

2,246,929 

2,307.088 

2.327.991 ,, 

2,329,927 

2,335,432 

2,526,572 

2.536.900 

2,547.1 19 

2,607,353 

2.625.163 

2,666,437 

2,679,251 

Most of these patents were furnished by Dr. P. H. Leake of 

the American Tobacco Company and Dr. A. W. Spears, Ill 

of Lorillard. A Division of Loews Theaters, Inc. A few additional patents were found by searching World Patents. This 

list is believed to be reasonably complete. 

Title 

Cigar and Cigarette Wrapper 

Cigarette 

Ash Retaining Cigarette and the Like 

Cigarette Holder and Extinguisher 

Cigarette 

Fire Safe Cigarette 

Cigarette 

Cigarette 

Smoking Article 

Cigarette 

Cigarette 

Cigarette 

Attachment for Cigarettes 

Cigarette 

Cigarette 

Decreasinq . lnflammabilitv of Ciqarettes - 

Cigarette 

Difficultly Flammable Cigarette Wrapper 

Design for a Combined Cigarette Holder 

Ashtrav and Extinauisher I (Desian I

Pat i 

Cigarette 

Cigarette 

Protective Cigarette Holder 

Processing of Tissue or Paper and 

the Product Obtained Thereby 

Cigarette 

Cigarette 

Cigar and Cigarette 

Method of and Composition for Treating 

Cigarette Extinguisher 

Combination Smokers Mouthpiece and 

Snuffer 

Cigarette 

Cigarette Holder 

Safety Cigarette Holder 

Cigarette Extinguisher 

Safety Cigarette Holder and Cleaner 

Cigarettes, Cigarette Paper and Tobacco 

Ash Receptacle 

Date 

2/21 /l882 

311 91191 2 

1121191 7 

1 112511 924 

9/29/1925 

412011926 

11/2/1926 

411 711928 

91311 929 

1 /21 11930 

711 511930 

3/31 il931 

9/1/1931 

912711932 

412511 933 

312511 933 

413011 935 

91311 935 

912211 936 

712811 936 

11/9/1937 

1012511938 

2/21 il939 

612411 941 

1/5/1943 

8/31 11943 

9/21 il943 

1 113011 943 

10/17/1950 

11211 951 

4/3/1951 

8/19/1952 

1/13/1953 

1/19/1954 

512511 954 

39 
A. U.S. PATENTS (cont’d) 

Number 

2,701,571 

2,718,889 

2,746,890 

2,754,828 

2,786,471 

2,788,005 

2.827.059 

2,890.704 

2,900,987 

2.932.301 

2,998,012 

3,030,963 

3,034,932 

3,081,776 

3.1 02,543 

3,165,105 

3.183.914 

3,220,418 

3,276,453 

3.288.1 45 

3,318,314 

3,528,432 

3.632.384 

3,702,117 

3,736,940 

3,821,958 

3.886.954 

3,916,916 

3,977,416 

3,985.1 43 

4,027,680 

4,034,767 

4.044.778 

4,091,821 

4,121,597 

4,146,040 

4,187,862 

Title 

Device for Smoking Cigarettes 

Heat Absorbing and Transferring 

Cigarette Device 

Cigarette and Method of Making 

Cigarettes 

Cigarette Smoking Device 

Cigarette Holder 

Cigarette 

Ash Retaining Jacket for a Cigarette 

Safety Cigarette Holder Made from 

Band for Cigarettes 

the Same 

Perforated Paper and Metal Foil 2,965,107 

Snuffer 

Cioarette and Wraooer Therefot ~ I~ ,I 

Cigarette Construction 

Tobacco Composition 

Cigarette Coal Anchor for 

Filter Cigarette 3,091,243 

Self

-Extinguishing Cigarette 

Safety Tip Cigarette 

Ash~Retaining Safety Cigarette 

Cigarette 

Cigarette 

Cigarette Construction 

Tobacco Article 

Apparatus for Producing a Continuous 

Tobacco Rod 

Cigarette or the Like Having 

Combustion Stop 

Method of Making Cigarette Paper with 

Ash

-Retaining Means 

Cigarette 

Cioarette with Ash

-Retainina Means 

FirklProof and Ash-Proof Cygarette 

Fire Safety Cigarette 

Shield for Cigarettes and Cigars 

Cigarette with a Snuffer 

Self Extinguishing Cigarette 

Safety Cigarette Holder and Ash 

Cigarette Holder 

Cigarettes 

Smoking Article Having an Ignition 

Filtering Pipe with Extinguisher 

Cigarettes 

Treatment of Cigarette Paper 

Retaining Device 

Suppression Disk 

for Cigarettes 

Date 

2/8/1955 

9/27/1955 

5/22/1956 . 711 711 956 

3/26/1957 , 

41911 957 

3/18/1958 

6/!6/1959 

8/25/1959 

4/12/1960 

Cigarette 

1212011 960 

8/29/1961 

4/24/1962 

511 511 962 

311 911 963 

512811 963 

91311 963 

1 /I 211 965 

5/18/1965 

11/30/1965 

101411 966 

11/29/1966 

51911 967 

9/15/1970 

1/4/1972 

1 11711 972 

6/5/1973 

7/2/1974 

6/3/1975 

111411 975 

8/31/1976 

1011 2/1976 

61711 977 

7/12/1977 

813011 977 

513011978 

1012411978 

3/27/1979 , 

2/12/1980’ 

40 
Number 

4,230,131 

4,241,742 

4,303,084 

4386 ,. 616 

4,413,638 

4,436,101 

4,452,259 

4,453,533 

4,480,650 

4,489,738 

4,491,139 

4,521,333 

4,582.073 

4,570,645 

4570,646 

4,570,650 

4,572,217 

4,582,073 

4,585.01 4 

4,615,345 

061627.710 

061877,803 

7045 

Title 

Self Extinguishing Cigarettes 

Ashtray to Control Burninq Rate 

of C;garette . 

SelfkExtinguishing Cigarettes 

Cigarette Tube 

Safety Cigarette Bottle 

Self Extinguishing Cigar or Cigarette 

Smoking Articles Having a Reduced Free 

Burn Time 

Treatment of Ciaarette PaDer 

Coated Self-Extiiguished Cigarette 

Self-Extinguishing Cigarettes 

Self~lgniting Smoking Device 

Intumescent Silicates Having Improved 

Self~Extinguishing Cigarettes 

Safety Holder for Cigarettes 

Method and Apparatus for Smoking 

Self~Extinguishing Cigarette 

Fire-Safe Cigarette Holder System 

Check Valve Type Cigarette Mouthpiece 

Fire Inhibiting Tubular Safety Shield for 

a Cigarette Type Smoking Device and 

Combination Thereof 

Stability 

Self~Extinguishing Cigarettes 

Reduced Ignition Proclivity Smoking 

NOTE: This is an application 

Smoking Articles 

NOTE: This is an application 

Wrapper Constructions for Self~Extinguishing 

and Reduced Ignition Proclivity Smoking 

Articles 

Article Wrapper and Smoking Article 

NOTE. This is an application 

Date 

1012811980 

1213011980 

1 21111981 

61711 983 

111811983 

311 311 984 

61511 984 

611 211 984 

1 11611 984 

1212511 984 

11111985 

612411 986 

811 711 984 

211811986 

211 811986 

2/18/1986 

212511 986 

411 511 986 

412911 986 

101711 986 

711 111986 

612411 986 

912611986 

41 
- 

6. FOREIGN PATENT 

Country 

Australia 

Belgium 

France 

France 

France 

France 

France 

France 

France 

France 

France 

France 

Germany 

Germany 

Germany 

Germany 

Number 

149,216 

659.839 

1,040.981 

1,402,088 

1,446,152 

1,517,262 

1,537,845 

1.553.960 

1.560.360 

1,590,223 

2,044,336 

Means 

2,177,138 

531.768 

549,936 

608,407 

1,663,652 

Title 

Improvements in Cigarettes with 

Filter Plugs or Other Internal 

Mouthpieces and Methods and 

Machinery Used in Their Production 

Improved Cigarette 

Safety Devices for the Use of 

Smokers 

Smoking Article 

Device for Automatically 

Extinguishing the Burning 

Ends of Cigarettes and Such 

Safety Process Designed to 

Prevent and Reduce Damages and 

All Types of Accidents Caused 

by the Ashes from a Burning 

Cigarette 

Cigarette with Ash

-Retaining Paper 

and Process for Its Manufacture 

Automatic Cigarette Extinguishing 

Cigarette Improvements 

Process and Means for the 

Manufacture of Cigarette Papers 

with a Perforated Flameproof 

Network; Papers and Cigarettes 

Obtained by These Processes and 

Means 

Process and Means for the 

Manufacture of Cigarette Papers 

with a Perforated Flameproof 

Network; Papers and Cigarettes 

Obtained by These Processes and 

Process for the Manufacture of 

Cigarette Paper with a Perforated 

Fireproof Network 

Medium for Extinguishing the 

Remainder of a Cigarette 

Extinguishing Cigarette 

Cigarette 

Cigarette Extinguishing Device 

Date 

1/24/1951 

6/16/1965 , 10/20/1 953 

51311 965 

71611 966 

3/15/1968 

813011 968 

1/17/1969 

3/21/1969 

5/22/1970 

2/19/1971 

11/2/1973 

8/14/1931 

51311 932 

112311 935 

1 111 1 11 967 

42 
Country 

Germany 

Germany 

Germany 

Great 

Britain 

Great 

Britain 

Great 

Britain 

Great 

Britain 

Great 

Britain 

Great 

Britain 

Great 

Britain 

Great 

Britain 

Great 

Britain 

Japan 

Japan 

Japan 

Japan 

Switzerland 

Switzerland 

Switzerland 

World Patent 

Number 

1,959,684 

2,906,417 

3,429,275 

19.694 

22.161 

340.884 

421,236 

805.693 

909,699 

1,113,941 

1,214,319 

2,175,189 

58.146 269 

58-1 83,084 

58~183,085 

59.14.781 

142,429 

240,987 

348,094 

8,604,468 

Title 

Self-Extinauishina - - Smokina 

Article 

Self6Extinguishing Filter 

Cigarette 

Smoking Article 

Improvements in Cigars. 

Cigarettes, or the Like 

Improvements in the Manufacture 

of Cigarettes, Cigars, and 

Similarly Used Tobaccos 

An Ash+?etaining Attachment for 

Cigarettes 

Improvements in and Relating to 

Cigarettes 

Improvements in or Relating to 

Cigarettes 

Improvements in or Relating to 

Tobacco, Reconstituted Tobacco, or 

Cigarette Paper and Products Thereof 

Improvements in or Relating to 

Cigarettes and Like Smokable 

Articles 

lmwrovements in or Relatina to 

Mouthpiece Cigarettes andiike 

Smoke Articles 

Self Extinguishing Cigarette 

Self Extinguishing Cigarette 

Self Extinguishing Cigarette 

Self Extinguishing Cigarette 

Cigarette with Fire Extinguisher 

Cigarette 

Extinguishing Mechanism on 

Manufactured Smoking Articles 

Filter for Cigarettes. Cigars. 

Pipes and the Like 

Self-Extinguishing Cigarette 

Date 

61311 971 

212011979 

8/8/1984 

511 511 9 1 3 

912511 902 

11811 931 

1211 711934 

2/22/1956 

10131 11 962 

511 511 968 

1 2/2/1970 

1 112611 980 

813111 983 

10/26/1 983 

1012611 983 

1/1/1984 

1 1/17/1930 

611 11 946 

911 511 960 

8/14/1986 

43