Regular maintenance and periodic supervision considerably diminish the probability of fires and explosions. Combustion, and more frequently explosion, might occur if the material is present in the vapour-air mixture in suitable concentration.
Some metals have such a high sensitivity that they are stored separately from air, in inert gas atmospheres or under a liquid that is neutral for the metals. If an inert foreign dust is mixed in a cloud of dust, the explosivity of the dust-air mixture will be reduced.
A portion of these gases support combustion e. On its own, the energy Essay on fire hazards of sparks is insufficient for the ignition of the materials in the environment Essay on fire hazards to initiate an explosion.
If this energy cannot be dissipated sufficiently and the reason cannot be eliminatedthe extremely large increase of temperature might lead to a fire condition that endangers the surrounding.
For these materials, the requirements for the conditions of storage and the rules for storing in the same place together with other materials should be carefully considered. Thermoplastic materials melt during burning, then flow and depending on their location if mounted in or on a ceiling produce drops which remain in the burning area and might ignite the combustible materials underneath.
The burning activity and affinity for oxygen of some metals such as magnesium are so high that after being ignited they will continue to burn in certain media e. It is known that industrial accidents and catastrophes are caused by dust explosions. During an explosion, high temperatures can arise that promote the ignition of the combustible materials in the zone of explosion.
Hot surfaces In practice, the surfaces of equipment and devices may warm up to a dangerous extent either normally or due to malfunction. If the dust concentration exceeds the highest concentration leading to an explosion, a portion of the dust is not destroyed by fire and absorbs heat, and as a consequence the explosion pressure developed remains below the maximum.
The safety requirements for storage of liquids, their handling, the technological processes, and the electrical equipment to be set up in their zone should be elaborated for each category of flammability and combustibility.
For ignition to occur with liquids, these must have the formation of a vapour space above their surface that is capable of burning. The fire hazardous properties of fibres of protein base of animal origin wool, silk, hair are even more favourable than those of fibres of plant origin, because a higher temperature is required for their ignitionand under the same conditions, their burning is less intensive.
Spontaneous ignition of liquids is also promoted if they come into contact with air on solid materials of large specific surface area. Spontaneous ignition of glass-wool and mineral-wool products produced from non-combustible fibres or inorganic materials covering large specific surfaces and contaminated by oil have caused very severe fire accidents.
The group of unstable materials includes the chemicals acetaldehyde, ethylene oxide, organic peroxides, hydrogen cyanide, vinyl chloride which polymerize or decompose in violent exothermic reactions spontaneously or very easily.
Metals It is known from practice that nearly all the metals, under certain conditions, are capable of burning in atmospheric air. At higher humidity, the ignition temperature of the cloud of dust will increase in proportion with the heat quantity necessary for the evaporation of humidity. This is valid also for the vapours of liquids.
Wood and wood products are combustible, and when in contact with high-temperature surfaces and exposed to heat radiation, open flames or any other ignition source, will carbonize, glow, ignite or burn, depending upon the condition of combustion. A large portion of the current flowing through places with increased resistance will transform to heat energy.
The heat energy released during overcurrents with large short circuits might result in a fire in the device affected by the short circuit, with the materials and equipment in the surrounding area coming to ignition and with the fire spreading to the building. Eddy currents might arise-with these harmful consequences-also in the metal structural units around high-voltage equipment.
The most frequent cause of overloading is that the number of consumers connected is higher than permitted or their capacity exceeds the value stipulated.
The factors that influence the explosion hazard for settled dusts are the physical and thermal engineering properties of the dust layer, the glowing temperature of the dust and the ignition properties of the decomposition products released by the dust layer.
Materials inclined to spontaneous decomposition show special ability to ignite spontaneously. Chemicals Knowledge of the hazardous parameters of chemicals is one of the basic conditions of safe working. Burning with flames or flaming is the process in the course of which the exothermic reaction of burning runs in the gas phase.
The dangerous characteristic of radioactive elements and compounds is increased by the fact that the radiation emitted by them may be harmful in several ways, besides that such materials may be fire hazards themselves. Burning phenomena and the phases of the burning process fundamentally depend on the physical and chemical properties of the material involved.
The most frequent causes of fires in electric devices and wiring are overloading, short circuits, electric sparks and high contact resistances. Sparking introduces a hazard foremost at places where, in the zone of their generation, explosive concentrations of gas, vapour or dust might arise.
A large number of tools in general use and various types of technological equipment operate with open flames, or enable the formation of open flames. Under normal working conditions, most electrical appliances do not release sparks, but the operation of certain devices is normally accompanied by sparks.
Dusts With regard to physical state, dusts belong to the solid materials, but their physical and chemical properties differ from those of those same materials in compact form.
Fire-retardant agents inhibit combustibility, ignition will be slower, the rate of combustion will fall, and flame propagation will slow down.
The lower and upper limit values of explosion concentration and the width of concentration range depend on the size and distribution of particles. Hydrazine, when set on any material with a large surface area, bursts into flames immediately.The aim of this research paper is to create a social awareness towards fire hazards and draw attention of the concerned administration to improvise the fire fighting strategies and enforce appropriate laws to tackle the problem.
Objective To conduct a detailed investigation concerning the increasing.
Fire Hazards And Precautions. Print Reference this. Disclaimer: Click on this link for a useful flash tutorial on fire extinguishers. Electrical Hazards. If you are the original writer of this essay and no longer wish to have the essay published on the UK Essays website then please click on the link below to request removal.
The different types of safety consist of being on the apparatus, safety in the fire station, personal safety, tool and equipment safety, safety in training, and emergency scene safety. Riding the apparatus is the most common danger to a firefighter. Fire Hazards of Materials and Products The presence of combustible material in combustible systems represents an obvious condition of burning.
Burning phenomena and the phases of the burning process fundamentally depend on the physical and chemical properties of the material involved. OSHA requires workers to train all employees to recognize fire hazards, use fire extinguishing equipment and systems in a safe and effective manner, and how to evacuate safely in the event that a fire cannot be controlled.
Fire safety becomes everyone's job at a worksite. Employers should train workers about fire hazards in the workplace and about what to do in a fire emergency. This plan should outline the assignments of key personnel in the event of a fire and provide an evacuation plan for workers on the site.