ISSN:0308-0501    

DOI:10.1002/fam.810100302

出版商:John Wiley&Sons Ltd.    

年代:1986

数据来源: WILEY

摘要:

AbstractA review of literature was undertaken to ascertain the current knowledge of the nature of the thermal decomposition products generated from ABS and the toxicity of these evolved productsin toto.The literature review encompasses English language publications available through June 1984. This literature surveyed showed that the principal ABS thermooxidative degradation products of toxicologic importance are carbon monoxide and hydrogen cyanide. The experimental generation of these and other volatile products is principally dependent upon the combustion conditions and the formulation of the plastic. The toxicity of ABS thermal degradation products has been evaluated by fire methods. The LC50(30 min exposure + 14 day post‐exposure period) values for flaming combustion ranged from 15.0 mgl−1to 28.5 mgl−1. In the non‐flaming mode of combustion, the LC50values ranged from 19.3 Mgl−1to 64.0 mgl−1. Therefore, no apparent toxicological difference exists between the flaming mode and the non‐flaming mode. The toxicity of ABS degradation products was found to be comparable with the toxicity of the thermal decomposition products of other common polyme

ISSN:0308-0501    

DOI:10.1002/fam.810100303

出版商:John Wiley&Sons Ltd.    

年代:1986

数据来源: WILEY

摘要:

AbstractThe available literature was reviewed to determine the nature and extent of information available on the thermal decomposition products and the toxicity of the combustion products of polyester materials used in consumer applications such as textiles and building construction. This literature review is limited to those publications printed in English through June 1984. The thermal decomposition products of polyesters are a function of temperature and oxygen content of the atmosphere. In general, as the temperature increases, the quantity of heavier hydrocarbons decreases and the production of CO and CO2increases. The presence of flame retardant additives, such as bromine and chlorine‐containing compounds, produce halogenated combustion products. The use of phosphorus and bromine together in the same flame retardant finish increases the concentration of low molecular weight compounds. Thirteen different test protocols have been used to evaluate the toxicity of various types of polyester. Non‐flame retarded polyesters give measuredLC50values ranging from 30.5 Mgl−1to 95.7 mgl−1, while flame retarded polyesters, haveLC50values ranging from 24.0 mgl−1to 38.0 mgl−1. Several exceptions, however, are noted. Toxicologists consider these differences to be not significant. In general, the results from large‐scale tests are ambiguous because of the presence of other materials in addition to t

ISSN:0308-0501    

DOI:10.1002/fam.810100304

出版商:John Wiley&Sons Ltd.    

年代:1986

数据来源: WILEY

摘要:

AbstractHydrogen chloride is the principal product released during the combustion of poly(vinylchloride). It is classified as a sensory and pulmonary irritant. The toxicity of hydrogen chloride (HCl) has been the subject of numerous acute toxicological studies on rodents to determine the effect of HCl exposure on humans during fires. The lethality studies show that HCl destroys the upper respiratory tract and the eyes of rodents. A few of the rodent studies measured the HCl concentration required to produce incapacitation within a given short‐exposure period. These concentrations were higher than the lethal concentrations due to the fact that most deaths occur post‐exposure. The findings from rodent studies were basically confirmed by exposing non‐human primates (baboons) to high HCl concentrations for 5 min and measuring escape potential. In the baboon study, no statistical significance could be found between the time‐to‐effect parameters, failure modes and the HCl concentrations. The relevance of the baboon behavioral model and physiological response to human escape‐potential in a fire environment that contains HCl is questionable. In terms of the behavioral model, the baboons were able to carry out the escape routine with their eyes closed during the exposure. Inability to see was not considered incapacitating. Humans would have great difficulty escaping from a fire with their eyes closed. Furthermore, the baboons escaped by one simple action; jumping out. Most humans could not escape from a fire by one simple, instantaneous act. Based on the review of HCl toxicity and basic toxicological principles, elements required for the development of an appropriate animal incapacitation model for irritants are proposed. Exposure of animals to irritants, such as HCl, will only provide information on human escape impairment from fire when the animal models address the direct result of irritant effects on vision and respiratory function. Most of the preset studies measure the delayed, secondary systemic effects that produce asphyxia. Clearly, the measurement of vision or the lack of vision should be of primary importance in any irritant smoke incapacit

ISSN:0308-0501    

DOI:10.1002/fam.810100305

出版商:John Wiley&Sons Ltd.    

年代:1986

数据来源: WILEY

摘要:

AbstractPenetration of the carbonized polymeric residues has been investigated and their influence on combustibility of polymers has been shown. It has been found that filtration of liquid and gas products of pyrolysis through the carbonized layer upon combustion is described by Darcy's law, the movement of liquids being due to the surface tension forces. It has been shown that the carbonized layer cannot be regarded as an important obstacle for passing of volatile and low‐viscous products into the gas phase, and that the polymeric melts can also rise through the coke due to the capillary forces. Phosphoric and some boric compounds have been found to cause a decrease in penetration of the carbonized residues, which can be one of the reasons of the flammability decrease of polymers when using such compound

ISSN:0308-0501    

DOI:10.1002/fam.810100306

出版商:John Wiley&Sons Ltd.    

年代:1986

数据来源: WILEY

摘要:

AbstractThe limiting oxygen indices of flame‐retardant treated wools have been determined at environmental temperatures up to 380°C. As the ambient temperature increases, the LOI decreases significantly until, within the temperature range of 308°C and 325°C, it reaches a minimum value, Above 325°C, the LOI of the carbonaceous residue increases rapidly with temperature. The minimum value reached for a number of retardant treated wools was below that for untreated wool. Broadly similar behaviour is exhibited by flame‐retardant cotton, modacrylic and Nomex°, although with the latter there is no increase in oxygen index at the upper end of the temperature range

ISSN:0308-0501    

DOI:10.1002/fam.810100307

出版商:John Wiley&Sons Ltd.    

年代:1986

数据来源: WILEY

摘要:

AbstractA simple logic is presented for expressing the equivalence of fire safety measures. It is based on the principle that any combination of safety measures is acceptable as long as it does not lead to losses (property and human losses) above the level accepted by society.

ISSN:0308-0501    

DOI:10.1002/fam.810100308

出版商:John Wiley&Sons Ltd.    

年代:1986

数据来源: WILEY

摘要:

AbstractThe purpose of this work was to examine the phenomena which determine the possibility of flashover occurrence and progress in compartment fires. A number of experimental fire tests were performed aimed at simplifying the phenomenon in successive tests by eliminating the factors influencing the main mechanisms which determine the occurrence of flashover in compartment fires. A physical model has been proposed as well as mathematical description of the flashover, including a simplified first stage of fire development. A new method for mathematical description of chemical mechanisms of combustion in gas mixture was employed according to which the experiments were considered to be simplified kinetic tests permitting the derivation of a substitute formula for chemical change. A computer program was developed enabling computation of the dynamics of the pre‐flashover fire phase. By means of this program, extensive theoretical analysis was performed of the influence on fire development of a number of compartment factors, including fire load, ventilation and potential fire siz

ISSN:0308-0501    

DOI:10.1002/fam.810100309

出版商:John Wiley&Sons Ltd.    

年代:1986

数据来源: WILEY

摘要:

AbstractA larger cone heater for the cone calorimeter has been developed in order to measure the rate of heat release from building materials. The aim was to facilitate the testing of inhomogeneous materials and to minimize edge effects. Specimens of two different sizes, 100 × 100mm and 200 × 200mm, were tested in the horizontal orientation. The maximum rate of heat release and the average rate of heat release during 1 min after ignition are generally higher for the larger specimens than for the smaller ones. The time to ignition is generally shorter for larger specimens. Results from tests with 13 different building materials, including wood‐based materials, gypsum board, wall‐coverings and plastics, are presented at different heat flux levels up to 75 k

ISSN:0308-0501    

DOI:10.1002/fam.810100310

出版商:John Wiley&Sons Ltd.    

年代:1986

数据来源: WILEY

摘要:

AbstractRecent data from large‐scale turbulent natural gas/air diffusion flames (135‐210 MW) were used to evaluate analysis of flame structure and radiation properties. The conserved‐scalar formalism, in conjunction with the laminar flamelet concept, was used to predict radiative heat fluxes. The narrow‐band model considered the nonluminous gas bands of water vapor, carbon dioxide, methane and carbon monoxide in the 1000‐6000mm wavelength range. Structure predictions were encouraging, with discrepancies for mean temperatures (ca200 K in the hottest portions of the flames) comparable to experimental uncertainties, due to thermocouple errors, flame disturbances from ambient winds and lifting and external expansion effects near the injector. Radiative heat flux predictions were also reasonably good, e.g. predictions based on mean scalar properties were generally 15% lower than the measurements. The findings also suggest that continuum radiation from soot is negligible for the

ISSN:0308-0501    

DOI:10.1002/fam.810100311

出版商:John Wiley&Sons Ltd.    

年代:1986

数据来源: WILEY