Five-hundred popular upholstery fabrics were obtained from commercial fabric shops in North Carolina. The ignitability of each upholstery fabric was characterized using a particular smoldering cigarette in a specified protocol with six replications. If one or more of the smoldering cigarettes resulted in smoldering of the fabric, the fabric was classified as ignitable. Of the 500 fabrics, 355 were found to be non-ignitable and 145 were classified as ignitable. The differences between the properties of ignitable and non-ignitable fabrics were examined. The results show that the upholstery fabrics' contents of sodium and potassium salts, their concentrations of cellulosics, and their basis weights (areal densities) correlate with ignitability. An aqueous rinse of upholstery fabrics rendered them substantially non-ignitable by the smoldering-cigarette used in this study.

Upholstery fabrics for residential use were obtained from various fabric shops and manufacturers' catalogs. Screening was conducted with four experimental cigarettes of varying design. By the National Institute of Standards and Technology (NIST) cotton duck mockup method, two of the cigarettes display "low" ignition propensity and two show "high" ignition propensity. Of the fabrics obtained for this study, 316 smoldered when in contact with at least one of the experimental cigarettes. Further examination within this set of upholstery fabrics showed once again that cigarette ignition propensity ranking are dependent on fabric characteristics. The number of fabrics that showed ignition propensity rankings opposite to the NIST test "ranking" was similar to the number that agreed with it. That is, on the fabrics with rankings opposite to the NIST ranking, cigarettes of "low" ignition propensity by the NIST test showed more ignitions than cigarettes of "high" ignition propensity by the NIST test. These results are consistent with those of a previously published study with a smaller set of ignitable fabrics. Fabric weight was a key factor in determining fabric ignition behavior; two of the cigarettes showed increasing ignition propensity and two showed decreasing ignition propensity with fabric weight. For the majority of fabrics, however, cigarette design was unimportant in determining ignition behavior; that is, no differences in ignition behavior were observed with the different cigarette designs. The physical and chemical properties of the cotton duck fabrics of the NIST test are such that they repre-JOURNAL OF FIRE SCIENCES, VOL.

Two bolts of cotton duck fabric that meet military specifications and the purchasing guidelines described by the National Institute of Standards and Technology (NIST) for use as a substrate in "Test Methods for Quantifying the Propensity of Cigarettes to Ignite Soft Furnishings" were tested with smoldering cigarettes to determine the effect of inter-bolt variations on cigarette ignition propensity test outcome. The test was designed around an ASTM method that calls for the control of all known test variables, except for those inherent to the fabric's manufacture. The ignitability of each fabric was determined by testing two sets of 48 replications for each of two experimental cigarettes. The two bolts of cotton duck fabric showed a statistically significant difference in ignitions, independent of environmental and experimental fac tors. Two additional bolts of cotton duck #4 were analyzed. Cigarette ignition test results and the physical parameters of the additional bolts offer evidence that the NIST specifications are difficult to meet and further that test results are extremely sensitive to fabric properties.

Fifty cellulosic upholstered furniture fabrics were purchased in the Richmond, Virginia area and tested to determine their ignition responses to eleven commercial cigarette brands. Six of the commercial brands (A-F) had been identified by the National Institute of Standards and Technology (NIST), using their cotton duck substrate test method, as having reduced ignition propensity. The six cigarettes had "unconventional" 4 characteristics deemed by NIST as likely to lower cigarette ignition propensity: smaller circumference, lower permeability paper, and/or reduced paper citrate. On the cotton duck fabrics, these cigarettes were extinguished frequently. On the fifty upholstery fabrics, the cigarettes rarely were extinguished. NIST also tested fourteen "conventional, "5 best-selling brands that their cotton duck test method classified as "strong" igniters. Five brands (1-5) tested here on upholstery fabrics were also major commercial brands of "conventional" design. Testing of the fifty upholstery fabrics and eleven cigarettes followed the protocol developed by NIST with exceptions that upholstery fabrics replaced cotton ducks and polyethylene film was not used between fabrics and foam. Standard ANOVA analysis of ignition responses of the fifty upholstery fabrics showed that the two cigarette types, A-F and 1-5, were statistically similar: the differences in igni-'Current address: KC Automation, Inc., Richmond, VA. 'Current address: Philip Morris, Inc., Richmond, VA. 3Author to whom correspondence should be addressed at: Brown and Wilhamson Tobacco Corporation, PO. Box 630, Dinwiddie, VA 23841-0630. 4Filter cigarettes of 97-120 mm length and 17-22 mm circumference. 'Filter cigarettes of nominal 85 mm length and 25 mm circumference. Downloaded from 414 tions reported by NIST using cotton duck as the test fabric were not found with this broad range of actual upholstery fabrics. Differences in ignition responses among the fabrics did range from igniting in all tests to not igniting in any test, and from igniting more frequently with the six "lower ignition propensity" cigarette brands to more frequently with the five "conventional" ones.