Flammability testing smoke

Polyvinyl Chloride (PVC) In flexible PVC, the partial replacement of antimony oxide with the zinc borate cannot only display synergy in flammability test performance but also results in dramatic smoke reduction.56 This synergy can be more dramatic when used in conjunction with ATH or magnesium hydroxide (MDH) (Figures 9.4 through 9.6). A recent Cone Calorimeter study49 showed that, in flexible PVC, the partial replacement of antimony with the zinc borate could reduce both the HRR and carbon monoxide production drastically at a... 

Modified Flammability Tests. A number of smoke tests exist in which the smoke produced by a flammability or heat release test is determined using photocell light systems positioned in the smoke streams. 

Apart from the specific techniques for testing smoke formation, a great number of the methods devoted to flammability testing (mainly for building materials) are also capable of ascertaining smoke formation. 

The above discussion shows that a definitive toxicity specification for combustion gases is much more uncertain than that for the strictly defined flammability or smoke production, in spite of the great number and variety of toxicity test results. Even the test procedures are less established — only one of them has been standardized so far (DIN 53 436). The Technical Committee 92 of the International Standard Organization (ISO) has reached only a Technical Report, ISO/TR 6543-1979, surveying the published test methods without any appraisal. 

Test Procedures and Performance Criteria for the Flammability and Smoke-Emission Characteristics of Materials Used in Passenger Cars and Locomotive Cabs, Fed. Reg., Rules and Regulations, Vol. 64, No. 91, Wednesday, May 12, 1999. 

Miscellaneous chemicals are used to modify the flnal properties of rigid polyurethane foams. For example, halogenated materials are used for flammability reduction, diols may be added for toughness or flexibility, and terephthalate-based polyester polyols may be used for decreased flammability and smoke generation. Measurements of flammability and smoke characteristics are made with laboratory tests and do not necessarily reflect the effects of foams in actual fire situations. 

As with flammability, tests play a key role in studies of smoke formation from burning polymers. A wide variety of tests have been used, often in conjunction with flammability tests. Hirschler has given a brief description of most of the main tests [12]. 

Different regulations, such as those of the Federal Aviation Administration, Department of Transportation, and local building codes, mandate that the designs of certain products comply with specific flammability test requirements. Flame-retardancy requirements generally include limits on flame spread, burning time, dripping, and smoke emission. A multitude of flammability tests have been developed, with more than 100 known just in the United States. The most common ASTM tests are given in Table 4-17. 

Most flammability (including smoke) tests are relatively small-scale, because experimental materials are often only available in relatively small quantities and it is prohibitively costly to bum complete stmctures. Small-scale tests are also more easily and more economically replicated than large-scale fires. Many tests have an inherent deficiency in that they fail to reproduce the massive effect of heat produced in a large-scale fire, and therefore may give results that can be misleading if applied in the wrong context. 

Table 8-2 lists existing flammability tests and other pertinent information. Table 8-3 lists smoke evolution tests and related information. 

Rate of Heat Release Test for Aircraft Cabin Materials. The Federal Aviation Administration requires (14 CFR 25.853) that large areas including interior ceiling and wall panels, partitions, galley structures, cabinets, and stowage compartments of commercial transport aircraft pass a rate of heat release test in addition to flammability and smoke tests. The rate of heat release apparatus (see Fig. 26) is a modified version of the ASTM E906, Standard Test Method For Heat And Visible Smoke Release Rates of Materials and Products (configuration A). 

Results are presented of a study of the influence of different fillers, plasticiser oils and curing systems on the limiting oxygen index and smoke emission of EPDM compounds, and of flammability tests undertaken on roof coverings based on three different compounds. 5 refs. 

FAA regulations on the flammability of materials cover the following burning behavior heat release (OSU Heat Release Test), smoke generation (NBS Smoke... 

Once ignited they produced considerable amounts of heat and smoke. Flame retarded flexible PU foams became available in 1954-55, i.e. within a few years of flexible PU foams becoming available in commercial quantities(22). These FR PU foams contained trichloroethyl phosphate or brominated phosphate esters and resisted ignition from small flame sources. Unfortunately they may burn when subjected to a larger ignition source or when covered by a flammable fabric and may then produce as much heat and more smoke than the standard grade of PU foam(3). This was identified by UK room tests in the early 1970 s and has been confirmed more recently by furniture calorimeter tests at the NBS(21). 

Place a small pile of the mixed composition on the fireproof board, insert a section of safety fuse into the base of the pile, and carefully light the end of the fuse with a match. Step back and observe the effect. Because of the generation of smoke by most pyrotechnic compositions, these tests are best conducted outdoors or in a well-ventilated area such as a laboratory fume hood. 3e certain no flammable materials are near the test area, for sparks may be produced. 

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