Identification of an Alternate Substrate for Testing Reduced Ignition Propensity Cigarettes

Results from ASTM E2187, ISO 12863 and NZS/AS4830 for testing the ignition propensity of cigarettes have limitations that include sensitivity to mass, moisture content, and surface roughness of the filter paper substrate, variations in test results when using filter paper produced in a different location, and reliance on a proprietary product. Therefore identification of an essentially equivalent substrate with good reproducibility across various manufacturers and batches is underway. A summary of results of the initial screening and preliminary identification of a likely alternate substrate are presented. INTRODUCTION ASTM E 2187, ISO 12863 and NZS/AS4830 describe essentially the same test method for the ignition propensity of cigarettes. This standard test method is the basis for less fire-prone cigarette regulatory requirements in the U.S., Canada, Australia, and the European Union. U.S. fire incidence statistics project a likely reduction of roughly 30 % in deaths from cigarette-initiated fires. The regulations require that the lit sample-cigarette be placed on a specified number of layers of Whatman No. 2 filter paper with the rough sides of the filter paper facing up. Testing is performed in a local environment (Figure 1a) where there is minimal disturbance of the air flow. The result recorded for each determination is whether or not a full-length burn of the cigarette is observed. Forty replicates are performed in a test. The number and percentage of full-length burns are reported. Examples of whether or not a full-length burn was observed are shown in Figure 1b. CURRENT SUBSTRATE The choice of testing on 10 layers of this brand of filter paper resulted from a good correlation of test results with the ignition propensity of cigarettes as measured on upholstered chairs. An interlaboratory study determined values of intralaboratory repeatability, r, and interlaboratory reproducibility, R, which were later deemed useful for regulatory purposes. i This commercial product is mentioned by name because it is explicitly required in the ASTM, ISO, Australian, and New Zealand standards. Such identification is not intended to imply BRANZ Ltd. or NIST endorsement of the product. ii Percentage of full-length burns (PFLB) is not a standard unit. However, it has become the figure of merit used worldwide in this field of testing. This paper reports values in this form in the interest of facilitating communication to the intended audience. Figure 1 Photograph of (a) a sample-cigarette being tested to ASTM E 2187, and (b) examples of fulllength burns (top and left samples) and a non-full-length burn (right sample).