In the progressive ignition portion of the testing for test #1, the Brazilian market television 1B ignited with a 60 s exposure to the needle burner. The fire produced sooty black smoke with the first flaming drops occurring at 24 s. The television stand collapsed at 316 s with a resulting rapid increase in heat release as seen in Figure 2. The flame propagation covered the entire back surface of the television as well as the front screen and the interior components.
In test #2, the Mexican market television 3M was ignited with a 60 s exposure to the needle burner. The first burning droplets fell onto the stand with the result of the stand also catching fire at 102 s. The fire produced black sooty smoke with the stand collapsing at 510 s. Figure 3 shows the heat release rate for this test.
In test #3 a 32 inch Brazilian market television 2B was ignited after exposure to the needle burner for 60 s. The first flaming droplets were noted at 111 s resulting in the stand catching fire and collapsing at 320 s. Figure 4 shows the heat release rate for test #3. The rapid increase in energy release corresponds to the base catching fire. The first flaming drips were seen between 5 min and 6 min with the subsequent rapid increase corresponds to the collapse of the TV stand.
In test #4 the first of the US market television 1US was subjected to the needle burner for 60 s with the result of a guttering flame that extinguishes at 87 s. The needle burner was then applied for 180 s with flames extinguishing at 192 s. A 50 W flame source was then applied to the television for 2 s to 10 s intervals, a 60 s interval and a 180 s interval all with no ignition. The 500 W flame was then applied to a previously burned area for 60 s without result followed by an additional 180 s which breached the casing and resulted in a very slow fire with a peak heat release rate of 5 kW and very little overall mass loss for the television. Figure 5 shows the heat release rate for this test with the Y axis scale expanded to show more detail.
In test #5, a US market television 3US was also subjected to the progressive ignition regime with very similar results as obtained in Test # 4. The needle burner was applied for 60 s with the result of a guttering flame that extinguishes at 96 s. Flaming drops were noted at 81 s that extinguished on impact with the floor. The needle burner was then applied for 180 s with flames extinguishing upon removal of the burner. The casing material melted during this process and retreated from the flame. A 50 W flame source was then applied to a different area of the television for 2 s to 10 s intervals, a 60 s interval and a 180 s interval all with no ignition. The 500 W flame was then applied to a previously burned area for 60 s without result followed by an additional 180 s but melting drops extinguished the burner at 105 s. The Burner was relit and the exposure continued for the remaining time. At 150 s into the exposure flaming drops were produced. A 180 s exposure was then performed on a previously tested part of the surface which produced a breach in the case and produced a slow fire that produced flaming drops. The fire self extinguished at 14 min 30 s. A pHRR of 2 kW was obtained as shown in Figure 6.
The last of the progressive ignition tests was planned to be test #6 however the ignition source was applied to the stand mounting bracket instead of the television case. The stands were determined to be a different material and were not UL-94 fire test rated. Test #17 using US market television 2US was the final progressive ignition experiment and was determined to be very similar to test 4 and 5. The television was subjected to the needle flame for 60 s with the result of immediately extinguishment on removal of ignition source. The needle flame was then applied for 180 s with flames extinguishing at 180 s. A 50 W flame source was then applied to the television for 60 s with the flame extinguishing in 62 s. It was then was then applied for 180 s with flames extinguishing at 180 s. The 500 W flame ignition source was then applied for 10 s without ignition followed by a 60 s exposure which breached the casing and resulted in a very slow fire over a period of 46 min with a peak heat release rate of 110 kW. Figure 7 shows the heat release rate for test #17.
In all subsequent tests, a 500 W ignition source was applied for 180 s to the back of each television. A total of two of each type of television was challenged under this technique. In all of the non-US market televisions this resulted in higher peak heat release rates in much shorter times. Comparing the 1B and 1US television, same model, gives the greatest contrast as shown in Figures 8 and 9. The Brazilian version reaches 295 kW in as little as 365 s while US versions fails to achieve sustained ignition. It is important to note that the red line in Figure 8, test 1, represents ignition with a needle flame while tests 7 and 8 used the 500 W burner. The minor differences in the tests 7 and 8 are more a function of the normal variability in flame spread on the surface.
The 3M and 3US televisions show the same trend but not as dramatically and there is more variability in the performance for both the US and Mexican market televisions as shown in Figures 10 and 11. This is primarily due to the design and composition of the television stands of this model. None of the stands were rated for fire and were significantly involved in the early stages of the fire in tests 9 (2 min), 10 (2 min), 15 (3 min) and 16 (4 min). The major difference between tests 15 and 16 is that the front face of the television becomes involved in the fire early in test 16 and not at all in test 15. In test 5 the stand was not involved in the fire and this television failed to achieve sustained ignition and test number 2 used the smaller, needle flame ignition source.
The 2B and 2US televisions were smaller in size than the other televisions tested in this program being a 32 inch model however the mass of plastics in the rear casing was actually higher than the 40 inch models. All of the tests for the 2B and 2US televisions can be found in Figures 12 and 13. The Brazilian televisions burned faster and with greater peak heat release rate than those comparable to the US market using the same ignition source. Test 3 and 6 were ignited with the needle flame. In test 6, the needle flame came in direct contact with the stand which ignited and resulted in near complete combustion of the television. It did require an extended time to achieve a rapid combustion, approximately 10 min. In the 500 W ignition source fires the non-FR televisions reached pHRR of near 280 kW at between 3 and 6 min. In test 17, the stand for the television was not involved in the fire, by selective location of the ignition source, and this television required approximately 30 min to achieve free burning with a steep rise in heat release rate as shown in Figure 13.
The summary of the heat release and smoke generation data is presented in Table 2. Events with multiple ignition attempts have an asterisk adjacent to pHRR time. Comparing the non-FR television from Brazil and Mexico to the US market televisions shows that the non-FR televisions were easily ignited on their back cases with a small candle flame and that they reach their pHRR in between 6.67 and 13 min. The US market television required much larger ignition sources of longer duration to achieve ignition. Using the larger ignition source on the Brazilian and Mexican television to provide a direct comparison of identical conditions to the US televisions shows that the pHRR for the Brazilian and Mexican televisions nearly doubles and/or the time required to reach pHRR decreased significantly. For Tests 7 through 16 and test 18, all performed under identical condition, the US market televisions either failed to sustain ignition or burned very slowly. All of the US market televisions were proven to be compliant with UL 60065 except the 2US televisions which were a marginal fail.
Table 2 SBI Heat Release and Smoke Data for All Tests
The US market televisions did produce more brominated dioxins and furans than the ones produced for Mexico or Brazil. Table 3 presents the data obtained for tests 7–18 for brominated dibenzo dioxins and furans (BDD and BDF). The total mass of BDD and BDF was calculated by multiplying the found total mass in the collectors by the dilution factor of the duct being sampled. The flow in the duct was 0.60 m3/s and the sampler flow was 1.38 × 10−4 m3/s giving a dilution factor of 4320. The numbers obtained for the US Market televisions are rational based on the structures of the FRs normally used in HIPS and ABS plastics [21]. In addition, the samples collected in each trial were also analyzed for chloro dioxins and furans. OCDD, 3268-87-9, was detected at just above background levels in all of the TVs except those made for the Mexican market. Also, 1,2,3,4,6,7,8,-HpCDD was detected at near background levels in Test #8 and #16.
Table 3 Brominated Dioxin and Furan Data for All Tests
Combustion gases were also analyzed for the gases listed in ASTM E-800 for tests 7–18. The data indicates that all of the gases of concern were below detection limit except carbon monoxide (CO) and carbon dioxide (CO2). The CO concentration exceeds 1,000 ppm for five out of six of the television for the non-US markets and 2 of those exceed the IDLH value, 1,500 ppm. Only one of the six US televisions exceeded the 1,000 ppm and it did not exceed the IDLH value; the stand was a major contributor to the fire growth in this test. Table 4 presents the data on the peak concentration of the combustion gases for this series of tests.
Table 4 Combustion Gas Analysis for Tests 7–18
Each test also had two intervals where Summa™ canisters were collected to determine other toxic indoor pollutants that were produced during combustion. The first value listed in Table 5 and Table 6 for each test represents the time of the pHRR and the second was collected at peak smoke. For situations where the pHRR and the peak smoke were concurrent, samples were collected in sequence without a time gap.
Table 5 TO-15 Indoor Air Pollutants
Table 6 Tentatively Identified Compounds
The TO-15 gases and the TICs shown in Tables 5 and 6 respectively were dependent on the materials of composition of the plastic case and possibly interior components of the televisions. Many of the monomers like styrene and butadiene are present in fairly high concentration in the smoke. The faster the plastics burned the more products of incomplete combustion were produced. Bromomethane was produced in roughly the same amounts whether or not the case contained brominated FRs. The Brazilian and Mexican market televisions produced significantly greater concentrations of acrolein in most cases.