3. Looking at the cigarette column of table 3 we see that 94 plus 38, Second, let us consider hazards addressable by improved safety in ignition sources. There are two categories of item types in table 3 which present hazards not directly addressable by item type standards. Adult female sleepwear is the first item type. Non-flammable material is not at present available in sufficient quantity to produce flame resistant sleepwear for all adult women. The hazard is most severe for elderly women, but unlike the situation with regard to children's sleepwear, there is no size difference to permit a distinction to be made between elderly female sleepwear and other adult female sleepwear. Even if sufficient fabric were available for an overall female sleepwear standard, a large portion of the population would be unnecessarily subjected to the higher cost and changed product characteristics of flame resistant sleepwear. The second item type not directly addressable by an item type standard is dresses, for similar reasons. It appears that the improvement of safety in kitchen ranges offers good potential for the reduction of kitchen range accidents in general (20 percent of all first-to-ignite cases involve ranges), and for the reduction of the adult female sleepwear and dress hazards as well. Table 3 shows that 54 adult female sleepwear cases (42 percent of the total) and 30 dress cases (32 percent of the total for dresses) involve ranges. Finally, consider hazards partially addressable by public education. The hazard represented by male shirt and pants ignitions is at present not completely addressable by either item type standards or improved ignition source safety, for the following reasons: 1. 2. 3. Of the 193 cases in which male shirts were first to ignite 135 (70 percent) involved males age 16 and older. This indicates that the shirt fire hazard is largely an adult problem, and at present sufficient flame resistant shirt fabric is not available. Even if technological considerations permitted a standard to be pro- There are many ignition sources involved with shirt and pants ignitions; therefore, improved ignition source safety would require effort in many areas. For these reasons, public education should be explored, perhaps in concert with the other two approaches, to fully address the male shirt and pants hazard. The examples given above are intended to illustrate the complexity of the fabric flammability problem. The item type standards now in force and in various stages of development address obvious hazards. The voluntary actions of the kitchen range and book match industries, which are currently considering ways to make their products safer, address another segment of the problem. Public education is a third approach which should be explored, because the magnitude and complexity of flammable fabric hazards make it necessary to use all available approaches to reduce these hazards. 3. ACCEPTANCE CRITERION As mentioned earlier, the acceptance criterion sets the level of performance that is desired within the context of the test method. Irrespective of the measured variable, the level of performance chosen must meet the test of technological practicability. This means that industry must be capable of producing flame retardant goods and that these goods be acceptable to the con sumer. In the case of children's sleepwear, this requires knowledge of the performance in the vertical flammability test of available flame retardant treatments and/or in making flame retardant fabrics that are suitable for use in this segment of the textile industry. During the early stages of the development of DOC FF-3-71 the availability of materials with satisfactory vertical flammability performance was limited to specialty end uses, predominantly for the military. However, sufficient research and development had been completed to make possible the marketing of a small quantity of flame retardant cellulosic children's sleepwear. Based on the performance of these pre-market and market materials in the vertical test, a char length criterion was developed. Figure 5 shows the results of tests performed on readily available fabrics that exhibited self-extinguishing properties. The histogram indicates that, of the materials tested, an average char length greater than 7 inches tended to result in complete specimen burns (specimen length is 10 inches), while the mean of all the average char lengths less than 7 inches was approximately 3.5 inches. Therefore, the selection of 7 inches as the char length criterion appears reasonable and technologically practicable. Figure 5. A histogram showing the distribution of average char length for a group of fabrics tested in the vertical test. A criterion (referred to as "residual flame time") was developed for molten material that continued to burn on the floor of the test cabinet, limiting burn times of such material to 10 seconds. This was incorporated in the standard for children of ages 0-5 years (sizes 0-6X), because it was noted that flaming material falling from a garment represented two additional risk factors. The potential existed for the falling material to cause relatively deep localized burns and increased the likelihood of secondary ignition of other materials thereby increasing the extent of injury. However, there is a difference between hazard and an unreasonable risk. These flaming drips can be considered an unreasonable risk to children that are relatively immobile (i.e. sizes 0-6X covered by DOC FF-3-71), but are less of a risk to older more mobile children (i.e. sizes 7-14). The proposed acceptance criteria for children's sleepwear sizes 7-14, therefore, differ from the criteria found in DOC FF-3-71. For children's sleepwear sizes 7-14 (PFF-5-73), the residual flame time criterion is deleted. In DOC FF-3-71, the most critical criterion is that the average char length shall not exceed 7 inches for a set of 5 replicate specimens. Secondary criteria are that no single specimen have a char length of 10 inches (specimen size: 3.5" X 10") and that no single specimen exceed the 10 second limit on residual flame time. The latter two criteria are secondary only in that a failure of average char length results in a unit rejection under the accompanying sampling plan. The same is not true of the single specimen criterion, which allows for sample retesting before unit rejection occurs. A description of the methodology used in developing the children's sleepwear standards clearly establishes the need for a synthesis between accident data and laboratory experimentation. The basic approach taken has application in areas other than flammability. Any consumer oriented product safety standard must consider the best available end use and accident data and, at the same time, represent state-of-the-art technology with regard to repeatability and reproducibility. The continued surveillance of accidents should, in several years, indicate the success or failure of this approach. [1] [2] [3] [4] [5] [6] [7] The Flammable Fabrics Act, 81 Stat. 568, 15 U.S.C. 1191, as amended and revised Dec. 14, 1967. Children's Sleepwear Sizes 7 Through 14, Notice of Proposed Flammability Standard, DOC PFF-5-73, Federal Register, 38, no. 47 (Mar. 12, 1973), 6700-6710. The Standard For the Flammability of Children's Sleepwear, DOC FF-3-71, The Flammable Fabrics Program 1970, Nat. Bur. Stand. (U.S.), Tech. Note U. S. Bureau of the Census, 1960 Census of Population, United States, [8] [9] [10] Mattresses, Notice of Finding that a Flammability Standard May Be Needed, McCarter, R. J., The Cause of Anomalous Behavior in the Vertical Flammability Test, Textile Chemist and Colorist, 4, no. 4 (Apr. 1972). Proposed Standard For the Flammability of Children's Sleepwear, DOC PFF-3-70, Federal Register, 35, no. 223 (Nov. 17, 1970), 17670-17673. [11] The Flammable Fabrics Program 1971, Nat. Bur. Stand. (U.S.), Tech. Note 749 (Dec. 1972), 62. For example, table 4, which is extracted from FFACTS [4], is a listing of the major sources of ignition that children 6-12 years old have encountered while wearing sleepwear. Almost 50 percent of the incidents reported involved electric or gas kitchen ranges. This is followed by matches and heaters, with approximately 17 percent and 16 percent, respectively. Tabulation of the heat sources - open flame, glowing surface, etc. is shown in table 5. The mode of heat transfer most frequently experienced in real life situations should be simulated in some manner in a test method. Since approximately 65 percent of the reported cases were the result of an exposure to an open flame, the selection of a Bunsen type of burner is justifiable. This is in contrast to the case of mattresses [8] where the typical mode of heat transfer is a smoldering ignition (e.g. a cigarette). The selection of a cigarette as the ignition source for the children's sleepwear standards is as inappropriate as the selection of an open flame ignition is for mattresses. Table 4. Sources of Ignition For First-to-Ignite Uncontaminated Table 5. Mode of Heat Transfer For First-to-Ignite Uncontaminated In both DOC FF-3-71 and the Proposed Flammability Standard for Children's Sleepwear 7-14, methane was selected as the standard fuel for the test burner on the basis that it is the gas closest to that presently used in homes. The ignition source is not completely defined until the duration of flame application has been specified. As can be seen in table 3, the traditional duration of flame impingement is 12 seconds. During a preliminary investigation of the effects of flame impingement time on char length, it was found that longer impingement time did not necessarily produce correspondingly longer char lengths. McCarter [9] has shown that for some marginally treated cottons longer char lengths were produced at relatively short exposure times as compared to tests conducted at longer exposure times. Figure 1 shows the effect of flame impingement over a range of exposure times on a marginally treated cotton fabric and a well treated cotton fabric. The well treated fabric ex |