رقم الدفاع المدنى 998

Fire Fighting


 

Introduction

Self-ignition

Extinguishing material

Some of the materials of the hidden poison

•  Introduction:
Praise be to God, peace and blessings on the Prophet. As narrated by Ibn Umar "Do not let the fire in your houses when you are sleep," agreed on and after,,,
man has identified fire from a long time ago and he used it as a primitive form in his daily life without knowing that it would be a cause for his death. Therefore, the fire is considered the oldest problems faced by the humans. And which gained the attention of scientists in study and research. And human in his nature is keen on the safety of his spirit and property that is considered one of the most expensive of what he has.
Therefore, the progress and development in many of the things life has led the human to use many tools and flammable materials. All these materials and other has caused the increase of the problems of the human beings with fires and access to an unfortunate end, in addition to the increase of the construction activity and high population density, the development of means of transport, increase of the industrial facilities that pushed the man to establish buildings of multiple floors and brought many of the techniques to accommodate this increase. The more the human developed the more the disasters are. These wars left many dead and a lot of fear and hunger, and here emerged the human demands to provide a device capable of handling such tasks. For this, the cooperative societies and governments started in the composition of this body to take over the implementation of those functions and organizing them and to seek as much as possible to have the power and material of the man in order to reach the goal for which this body was found. The Security Committee is one of the first fire-fighting organizations in history, and which was found by the Roman Empire.
In Saudi Arabia the first civil defense was established in the Kingdom of Saudi Arabia in the holy city of Mecca in 1346 e, it was a unit where the order was issued on 1/1/1346 e that required to the formation of the fire team within a municipality.

•  Self-ignition:
Is the rise in the temperature of the material internally without the presence of an external heat source until it reaches the temperature of the substance to the flash point.
Self-ignition occurs in some materials susceptibility to severe corrosion, and during this process a large amounts of heat is released, and this heat accumulate increasing oxidation and ignition occurs without an external source of blast-off.


  It is exemplified by the following:
• Chemical analysis:
Sometimes the length of storage of the substance is a negative impact on the material itself where there will be a dissolvent of the elements causing self-ignition.
For example: nitrocellulose material used in manufacturing paints require a certain degree of moisture to be conserved, however, the length of storage change the humidity (below), which helps in the dissolvent of the material and to the increase in temperature to the point of ignition.
The chemical reaction due to the friction of a substance with another:
Sometimes we find that when some substances interact with others ignition occurs without an external source of ignition in that when the Union of those materials with each other, a heat is released causing the ignition.
For example: during the contact of sodium or calcium with water, the temperature rise and the water brakes back into oxygen that helps in combustion, and to hydrogen that ignite when the color of the flame yellow in case of sodium and violet with calcium. As well as the addition of oil to the white phosphorus produces severe ignition and this is the way the manufacturing some of the bombs.

• oxygen absorption feature:
Some porous material composition such as coal have the capacity to absorb oxygen through its small holes, accompanied by a rise in temperature, which in turn lead to self-ignition, and this process depends on the availability of oxygen found the in the place where the softness of coal which helps to absorb the oxygen that exists in the atmosphere and thus rapidly increasing Temperature.

• the proliferation and growth of bacteria:
Bacteria multiply due to the increase in the proportion of moisture in organic matter such as barley, straw and sawdust or in the presence of medium within these materials and due to this gradual rise it results in the raising the temperature stored until it reaches the flash point and this process may take a relatively long time up to the weeks knowing that by Increasing the temperature it leads to an increase in oxidation.
For example: the proportion of moisture in storage of barley should be no more than 12% a hot country or the environment will become subjected to bacterial proliferation. Also it must not exceed 15% in the cold country.

• slow oxidation feature:
We have stated previously the three types of oxidation, including the slow oxidation where we find that some organic materials such as cotton contaminated with vegetable oils or animal, and when it is dried it gains the characteristic of the association with oxygen, leading to a release of an adequate temperature for self-ignition. As well as cloth used in the cleaning the falling oil, and cleaning the hands from oil can cause self-ignition if left neglect for some time. As well as vegetable oils such as linseed oil and oil soy is the most important can be self ignited in case it was used. Those fall materials are used in the manufacture of wood, such as varnish and polishing oils. The self-flammable vegetable oil needs to be about (4 - 6) hours after the painting. The danger is if it fell on the sawdust on the ground of the carpentry workshop where a fire can take place inside the workshop after closing at night.


•  Extinguishing materials:
The appropriate choice of materials to extinguish fire helps greatly in the eradication of the fire and very quickly, there are a number of materials used in firefighting operations such as:
1 - Water       2 - foam      3 - carbon dioxide      4 - powder      5 –Ahaljohnnyp materials


First: Water

water is the most common material used in firefighting operations, for its accessibility and cheap price, in addition to its large effectiveness in the fire. For this the firefighters use as well as all people usually water to put out the fire from various sources and through multiple long ago.

Qualities of water:
 water Takes the liquid state in the normal temperature, it is a liquid of no taste, color, and smell during its boiling at (100) and has a high capacity to absorb heat and thus cooling. the volume of water increases when it is in the solid state and its density becomes lower. it is a good conductor of electricity, for this it is advised to cut off electricity before the fire operation takes place. it is a good Solvent for the ion materials. As well as the water contains dissolved air, and these parts that are occupied by air is what is operated by the dissolved salt or sugar.
Types: There is water everywhere – it covers a large part of the land (about three quarters) as an ingredient in every organism, with the meaning (we make of water everything alive) and types: 
- pure water 
- Fresh water 
- Salt water.

• Chemical properties of water:
Water has several chemical properties, such as:

- Specific heat. 
- Freezing. 
- Boiling. 
- Sea (evaporation)

The impact of water in fire:
1) Cooling:
water works on cooling the burning material and absorbing heat and reducing it to a lesser extent than the flash degree.
2) Suffocation:
it takes place when the water turns to a steam. And this heavy vapor reduces the ratio of oxygen necessary for the continuation of ignition (i.e., preventing oxygen).
3) Emulsifying:
Is that water molecules are associated with the fluid molecules that are not soluble in air emulsified and incombustible. The emulsion is composed of a sprinkler to put the appropriate amounts of water on the liquefied burning in which the drops of the water permeate quickly in the substance, until the water is able to cover each drop of the burning liquid. And not to leave the surface of the liquid continues in the ignition with some large liquid viscosity sin which the penetration of the water and its falling to the bottom is relatively slow. And this great mix between water and burning liquid droplets, its cooling is more to the way of achievement. in addition to the amount of heat absorbed by water drops that swim on the surface of the burning liquid and spread above it before mixing with, in addition to what the water drops avsord from the parts of the burning liquid with a high temperature that loses and lowers its temperature according to the amount of water used.

4) Less concentration:
Since the addition of water to the liquids fires that are immiscible with water leads to reduction the combustible material and thus delay or lack of ignition.

• Second: foam
1) It is gas bubble of different ways of liquid water that can float on the surface of the flammable liquids veiling oxygen leading to the fire.
2) The main substance of the foam: is the protein produced from vegetable, animal protein such as bones, nails, and some other chemicals.

• Foam sections:
1) Chemical foam:

Produces a chemical reaction between two molten separated from for the foam in consisted during the mixing of these two composed foam if the molten mix together. It is made of aluminum sulfate + sodium bicarbonate.


 • Mechanical foam:
It is produced due to the mixing the solutions when their concentration is lowered due to the addition of water foam mechanical parts are:

• protein foam:
Consisting of a natural protein soluble in water, added to it several other material which protect it from freezing and protect the pumps from rust and reserve the foam from damage and make them in a fluid state ready for use.

 
•  fluorine - protein foam:
It is protein foam in addition to a small percentage of the element fluorine which makes its weight light. For the fluorine – protein foam isolates the air from the surface of the burning liquid, where the foam is a thin layer that covers the surface of the burning liquid and by this it is preventing the flammable vapors of the burning liquid from coming out.

 
• the light-water foam:
It consists of hydrocarbon fluorine dissolved in the water in addition to other chemicals that are anti-freeze and this type is characterized by a low degree viscous which makes it to flow quickly, with a light color that ranges between transparent and yellow.

 
• high foam-proliferation:
It consists mainly of fresh water in which the sulfate and ammonia are dissolved. It is characterized by big bubbles within them found air or gas that is not flammable. And its wall consists of thin cover of the water solution that characteristic.

 
• Concentrating foam that is resistible to alcohol:
These materials are made of fluorine – protein or normal protein ready to dissolve in water and are not soluble in alcohol. It protects the components of the bubbles of melting in addition to other foam materials made from synthetic materials containing jelly substances that
surround the bubbles and consists a layer over the liquid surface that should be extinguished.

 
• Foam characteristics:
Cohesion strength - strength of adhesion
Free flow - light weight


• extinguisher gases:
The carbon dioxide is an old fire extinguisher that has proved its presence in the past and present due to its relatively low price.
Characteristics:
o Is mobility.
o Poor conductor of electricity.
o Can be stored as a liquid for fire fighting
o Is not damaged no matter how long it has been stored


• Fourth: powder:
Is a dry powder that is used as an extinguishing material? It is a chemical salts that have been mixed in the laboratory and turned out to be as an extinguisher such as the Munix powder, which is currently one of the best types of chemical powder. Powders are several types such as:
o powder used against the fire category (b)
o multi-purpose powder for fire category (a, b)
o powder used against fires category (d)


• Types of powder:
There are several types of powder, according to the color of the element it is generated from, such as powder pink, blue, yellow powder, such as yellow: the presence of some aluminum products.

• Fifth: helium substances:
Is the composition of elements such as fluorine, chlorine, bromine, and iodine.
It consists of the following elements:
o Immediately
o chlorine
o bromine
Iodine: a solid dark purple that turns into violet fumes due to heating, for this methane is replaced by it for the iodine is solid and toxic.


How the helium gas works as a chemical fire extinguisher and its definition is:
Helium gas is a methane gas consisting of one atom of carbon and four hydrogen atoms occurs breaking of the interrelationship between carbon and hydrogen atoms where the fluorine or chlorine or bromine replaces hydrogen leading to become what is now. And this new combination is heavier in the atomic weight than the first one. This new combination settles on the surface of the fire followed by an increase in the link which requires a great force to disjoin it.

• types of helium substances:
Some are used to combat sensitive electrical appliances and aircraft fires such as helium(104), consisting of carbon tetrachloride trade name of (CTC) was used frequently in the past for electrical fire, but currently they have stopped using it due to the large number of toxic gases produced by if exposed to heat, also there is helium(1011) consists of chlorine methane symbolized by the symbol (CB) now being used in Germany against fires of category (b),  it contains bromine (Br2), which is a removal of oxygen or hydrogen from fire, in addition to its operations stifle the fire and cool it in the same time. And the (BCF) does not cause rust or corrosion for the most types of metals. It's quick and effective and can be used for all types of fires. Its evaporating is degree (4 º)for this when this liquid is being discharged from the cylinder it turns into a gas or vapor.


•  Some of the substances with a hidden poison:
 Carbon monoxide:
The carbon monoxide with the chemical symbol (CO) is a kind of the gases that has, no color, taste, or smell, for it is a gas that is chemically balanced as it is relatively lighter than air, and it is ready to ignite where it can turn to carbon dioxide. The carbon monoxide gas generates from incomplete combustion of carbon materials, as well as generated by internal combustion such as the engines in cars and in particular in the presence of defects or incompetence of some of these machines. And a carbon monoxide is prepared in the laboratory due to the sulfuric acid and formic acid together.

 
 Methods of poisoning by it:
Carbon monoxide is responsible for many deaths annually, and the most cases that happen take place in winter, especially as a result of heating by using coal in small unventilated rooms, and carbon monoxide causes the deaths of more victims of fires, especially within the buildings and before the fire reaches them. As the poisoning is not accompanied by pain, since the gas quickly causes the loss of the ability to move and speak prior to a coma death. Poisoning by carbon monoxide can happen in the smoke cigarettes and tobacco for it is one of its main components.
 How the human beings are poisoned by the carbon monoxide gas:
When carbon monoxide gas is inhaled, it would deprive the body's cells of oxygen, for the carbon monoxide gas is united when inhaled with the hemoglobin consisting the cherubim hemoglobin, and since each of the carbon monoxide and oxygen unite at the same group of chemical hemoglobin molecule, so the cherubim hemoglobin is incapable of carrying oxygen leading to the deprivation of oxygen in the cells. And the extent of saturation of the carbon monoxide in the hemoglobin depends on the concentration of this gas in the air, and on the time of exposure. For this the body demands of oxygen depends on the type of activity that the individual does and the amount that his tissue needs in addition to the concentration of the hemoglobin in the blood.

 Symptoms of poisoning:
The symptoms and signs of poisoning of carbon monoxide are revealed within the following three factors:
o The quantity of gas concentration in the inhaled air.
o Duration of exposure to carbon monoxide gas.
o The activity done during the inhalation of the gas.
These three factors lead to an imbalance in the amount of cherubim hemoglobin in the blood, which in its turn lead to the presence of the symptoms of the need of oxygen to the body, especially the brain. If the amount of gas and duration of exposure have increased the human starts feeling a headache accompanied by anxiety, confusion and a sense of dizziness and imbalance with the visual sense, nausea, vomiting and fainting occurs when you make any additional muscular effort to is, then it develops into a coma and respiratory failure and then death. And if a person inhaled a high concentration of carbon monoxide in the beginning, incautiousness and coma are symptoms quickly appear without any preliminary foretaste. But when there is a gradual poisoning the poisoned person by the carbon monoxide gas can notice the loss of his ability to make any effort with the difficulty of breathing when moving then when he is at rest with the high secretion sweat and a sense of fever. The poisoning of carbon monoxide gas is associated with symptoms of inflation of the liver and skin manifestations and the increase in the number of white blood cells and bleeding, and glucose and albumin are shown in the urine sometimes. One of the most serious symptoms of gas poisoning is the brain stroke and an increase in the pressure 0f the cerebral due to the increase in the disappearing of the blood capillaries of the brain that suffer acute shortage of oxygen, and the suffering of the heart muscle from the lack of oxygen The most distinctive symptoms of gas poisoning from the carbon monoxide is colored skin and mucous membranes of a red color due to the color of the cherubim hemoglobin which is glittering.


 treating poison:
The patient who is suffering from the poisoning of carbon monoxide gas is relieved by giving him artificial respiration effective in the presence of oxygen and in the absence of any trace of carbon monoxide. And this pure oxygen is used if possible, to allow it to take the place of carbon dioxide gas and at least partially to mitigate the effects of lack of oxygen to the tissues of through the dissolving of oxygen in the blood plasma, and for this purpose the pressurized oxygen is used in cases of serious poisoning of this gas. And a blood transfusion or transfer of red blood cells may have an effective impact in treatment. To reduce the need of the tissue for oxygen, the patient must remain completely at a standstill, and resort to cooling the body to help reduce the need for oxygen. And in the progress of treatment, the symptoms of poisoning begin gradually disappearing, but in the event of a continuing and severe shortage in the arrival of oxygen to the tissues may show symptoms of nervous shakes, mental disorder, and mental and behavioral. And maybe there will be microscopic changes in the cerebral cortex and heart muscle and other organs.


 hydrogen sulfide gas
ydrogen sulfide gas with the chemical symbol (H2S) is also known as "hydrogen gas" because it often emitted from the mold of the wastes with a disgusting strong smell. In these high levels hydrogen sulfide gas can make you sick or may cause your death.

 
 What is hydrogen sulfide gas?
It is a strong foul-smelling gas and like the smell of rotten eggs. It has no color and it is found in a natural way in the environment. And may consist and emit in the presence of the wastes containing sulfur. The wastes of the livestock and water sewage for man and the trucks that transport waste and chemical waste may emit hydrogen sulfide gas. as well as it is possible to have the gas in groundwater, especially in wells near the oil fields or wells that permeate the rocks and in the areas of oil refineries. As well as this gas can be could be emitted through industries based on sulfur compounds.


 How to get exposed to hydrogen sulfide gas?
You may be subjected to this gas by inhalation or even through the skin or the eye. And this exposure to hydrogen sulfide gas may occur in the home, or at work. If this exposure was at home it may occur through the sewages, which contains hydrogen sulfide gas. This gas has the smell of ‘Bad eggs", which is a foul smell. Therefore most of those who work in the field of livestock, sewage treatment, oil refineries, and chemical companies may be exposed to hydrogen sulfide gas in the area of their work.


 Its impact on human health
You May smell hydrogen sulfide gas in a very small level in a large place filled of air. And to be exposed to higher levels of hydrogen sulfide gas can lead to eye, nose and lungs agitation. Although the gas hydrogen sulfide stink for a strong sense of smell and consequently leading to the agitation of the eye and dizziness, cough and headache and may be fatal and in a quick way. Deaths occur when people enter the poorly ventilated places such as sewage systems and deep wells underground liquid tanks, and this gas is heavier than air for  this its concentration is considered to be higher near the surface of such places.
And it was found that the problems of the nervous system are for a long period of time to those who were subjected for this gas in a short term but at high levels. Also heart injuries have been monitored in such cases.


 How to be secured from the hydrogen sulfide gas?
o To ensure that the sewage pipes were installed and maintained properly.
o Through the identification of the source and then removing it and particularly in the plumbing.
o Increase ventilation and air conditioning in the areas affected by this problem, may temporarily reduce exposure to this gas.
o Must follow the guidance that limit the exposure to the chemicals such as hydrogen sulfide gas.