Flames fire risk assessment

When assessing the risk to the occupants of a premises from fire and the safety of the means of escape, account must be taken of the type and materials of construction of the building, the type and condition of the contents and particularly its flammability, the likely rapidity of spread of smoke and flames and the use to which the building is being put. Fire risk assessments are dealt with in detail in section 4.2.13. 

The use of flame retardants came about because of concern over the flammabiUty of synthetic polymers (plastics). A simple method of assessing the potential contribution of polymers to a fire is to examine the heats of combustion, which for common polymers vary by only about a factor of two (1). Heats of combustion correlate with the chemical nature of a polymer whether the polymer is synthetic or natural. Concern over flammabiUty should arise via a proper risk assessment which takes into account not only the flammabiUty of the material, but also the environment in which it is used. 

Fire safety in a particular scenario is improved by decreasing the corresponding level of fire risk or of fire hazard. Technical studies will, more commonly, address fire hazard assessment. Fire hazard is the result of a combination of several fire properties, including ignitability, flammability, flame spread, amount of heat released, rate of heat release, smoke obscuration and smoke toxicity. 

It is important to look beyond the initiating event to determine the potential for fire to spread to adjacent areas. If the fire is not detected early and quickly controlled, then the fire can escalate and involve other equipment and units. For escalation to occur, the fire must impact adjacent equipment by either radiant heat or flame impingement. In most risk assessments, escalation is taken into account by establishing a rule set. If any of the conditions within the rule set are exceeded, then escalation is assumed to occur. Typically, rule-sets may include ... 

FIGURE 15.21 Using the Petrella plot for comprehensive and reasonable scientiflc assessment of flame retardancy by comparing different approaches, or by comparing the effects for different irradiations. THE stands for the Are load and PHRR/tig for the fire growth rate hence, the two most important fire risks are monitored at the same time. An ideal flame retardancy would decrease both hazards significantly as is the case for the combination of both flame retardants on the left (comparison of HIPS), HIPS/Pmd, HIPS/Mg(OH)2, and HIPS/Pmd/Mg(OH)2) and for low external heat flux on the right (comparison of PA 66-GF and PA 66-GF/Pred for different irradiations). 

In summary, cigarette smoldering and open flame are the two types of ignition considered in assessing fire risk. Federal cigarette standards are in place for the mattress industry. 

Furthermore, the human health section of the EU Risk Assessment has concluded that the fire retardant additive TBPBA carries no risks, and the EU Scientific Committee on Health and Environmental Risks (SCHER) has confirmed the EU (Risk Assessment) conclusions that TBPBA presents no human health risk. TBPBA is a brominated flame retardant (used in electrical equipment including computers, televisions, and in printed wiring boards (PWB), and so on [21],... 

Risk assessment How could this candle flame harm you How could the name start a bigger fire ... 

Accidental fires interact with their environment, should this be pipework, equipment and structures in process plants in petrochemical industry, or facilities on offshore oil and gas installations. For plant design and risk assessment, cautious best estimates and uncertainty ranges are required for a number of combustion parameters. These include release rates, flame size and shape, heat output, thermal radiation to its environment, and the heating-up of structures, pipework and items of equipment. The estimate can result in the assessment of time to loss of functionality of these structures and pressurized equipment. 

The fire effects that are of most interest in assessments of fire risk are flame length and diameter, and incident heat flux. 

The properties derived from ASTM E1321 provide information about the flame spread characteristics of materials and can serve as an indication of their hazardous characteristics [38]. The test results provide material fire parameters that correspond to property data required by theories of surface flame spread [38]. The analysis may be used to rank materials performance by some set of criteria applied to the correlation or the analysis may be employed in fire risk growth models to develop a more rational and complete risk assessment for wall materials [38]. 

It concludes that there are many benefits from using flame retardants. An example is the reduction of the risk of death or injury from a fire involving consumer products, such as upholstered furniture, by between 30-90% when flame retardants are used. The UK government accepted the report as an important contribution to the debate on the use of FRs in consumer products and is also supportive of the risk assessment work commissioned by the EU, underway in the mid 1990s. 

Modem fire protection techniques have developed through multidiscipline activities in science and engineering and involve careful selection of materials, end-use product design and manufacture, and fire performance and risk assessment. Reducing the flammability of materials is still an essential primary fire safety consideration. PP is an inherently flammable material and therefore flame retardant treatment of the polymer is an essential consideration in relation to fire safety. For material scientists, however, it is also very important to be aware of developments in fire safety science and engineering including the transition from prescriptive to functional regulation of fire safety in many coimtries. 

In addition, at least 16 people die each year in Europe, based on UK and European statistics. These are known to be conservative due to the cautious estimate of the frequency of TV fires, based on the HB rated sets in Europe. It is conjectured that there may be up to 10 times this munber. In the US, however, there is no record of any deaths from fires related to the VO rated sets in that coimtry. Thus, the risk to human life must not be ignored in any overall assessment of the risk from flame retardant additives. 

The fire tetrahedron indicates that if any of the elements is sufficiently reduced the propagation of the fire ceases and the full flame phase of the fire is prevented. One can envisage fire safety case reports using the fire tetrahedron as a basis, where for each operational mode of, for example, an off-shore fire management system, where the occurrence and significance of each tetrahedral element is judged to determine a level of risk priority. In turn each operational mode of a system is assessed to see if one or more of the four tetrahedral elements can be removed completely, or reduced to a level that would prevent fire propagation. 

The start of every selection process should be an identification of the hazardous chemicals and an exposure risk analysis. The risk analysis may identify other methods of mitigation potential exposure that may reduce or eliminate the need to rely on CPC. You should assess exposure from skin absorption and skin effect from burns, sensitization, and/or other chemical hazards. Assessments should also consider biological, heat, fire, and mechanical hazards that may factor into the selection of CPC. Also, the hazards presented by CPC should be considered. CPC may contribute to heat stress, reduced mobility, obscured vision, difficulty in communication, lessened hand function (dexterity, grip, tactility), poor comfort, and skin illnesses. CPC may also affect the efficacy of other PPE worn, for example, ear muffs and respirators. Also, the other potential hazards (e.g., heat and flame) should be identified in the early stage of selection. 

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