• Fire Science and Engineering
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• v.32 no.2
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• pp.1-6
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• 2018

The combustion characteristics of cypress wood coated with boric acid (BA) and ammonium pentaborate (APB) were examined using a cone calorimeter according to the ISO 5660-1 standard. As a result, the combined specimens of boric acid and ammonium pentaborate (BA/APB) led to an improved fire performance index due to their synergistic effect. In addition, the total heat release values of the specimen coated with the boron compounds were 6.1~14.1% lower than that of the base specimen. The total smoke release rate (TSR) of the specimens coated with the boron compound decreased throughout the combustion process, except for BA/APB. The maximum concentration of carbon monoxide was reduced by 15.8~25.5%. In general, wood treated with flame retardants has a lower fire hazard.

• Fire Science and Engineering
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• v.32 no.3
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• pp.19-26
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• 2018

Experiments on the combustion characteristics of untreated wood specimens and also treated ones with boric acid and ammonium pentaborate were carried out using a cone calorimeter according to ISO 5660-1 standard. As a result, comparing to untreated specimen, the fire performance index (FPI) of the specimens treated with boron compounds increased by 1.2 to 2.1 times and the fire growth index (FGI) increased by 1.6 to 8.4%. Also, total smoke release rate (TSR) was 9.0 to 28.3% lower than that of the untreated specimen. It is understood that the test specimens treated with the boron compound produces a carbonized layer with a flame retarding effect. The highest CO concentration, 0.01112%, for the untreated specimen was observed at 418 s, but the specimens treated with boron compound decreased 13.2 to 37.5% compared to untreated specimen. Therefore, wood treated with boron compounds is expected to have lower fire hazards and risks.

• Applied Chemistry for Engineering
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• v.29 no.4
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• pp.413-418
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• 2018

Cypress woods treated individually with boric acid (BA4), ammonium pentaborate (APB4), or BA4/APB4 additives were examined for combustion gases. Each of the specimens was painted with a 4 wt% solution of boron compounds three times. Dried at room temperature, the combustion gas was analyzed using a cone calorimeter (ISO 5660-1). Consequently, the second maximum oxygen consumption rate of the specimen treated with boron compounds was 0.1067 to 0.1246 g/s, which was 5.3 to 18.9%, respectively lower than that of the blank specimen. The specific extinction area of specimens treated with BA4 and APB4 was also 2.0 to 19.0% lower, respectively. However, treated with BA4/APB4 showed 21.2% higher than that of the blank specimen. The maximum carbon monoxide concentration of the specimens with boron compounds was reduced by 0 to 25%. It was estimated to be 1.6 to 2.2 times higher than the permissible exposure limits by Occupational Safety and Health Administration (OSHA), indicating a fatal toxicity. The boron compounds were effective in reducing carbon monoxide, but didn't meet the OSHA limit. The boron compound inhibited the burning behavior of the cypress wood, which suppressed the second maximum oxygen consumption rate by 5.3 to 18.9% and the maximum carbon monoxide generation by 0 to 25%.