The following is a discussion on the topic flammable and combustible liquids, how they burn and take various aspects. This discussion is particularly interesting to anyone who wants to gain an understanding on the element of fire.
This research paper will take a summary approach where it shall provide a summary of information acquired from various sources and how it can be used in order to control fire from different sources.
The first discussion shall be on the definition of flammable liquids. The flammable liquids are liquid elements, which can be set ablaze under certain conditions. Flammable are further classified into two categories, those that are flammable and those, which are combustible as per their flash points.
To understand the differences better flammable liquids ignite faster or they catch fire very easily at room temperatures. Combustible liquids on the other hand burn at temperatures, which are frequently above the normal temperatures (Henri 22).
There are many ways of identifying whether a particular liquid is combustible or not, in order to have prevention measures at the right time.
One of such criterion is using information provided by the Workplace Hazardous Materials Information System, which states that flammable liquids have their flashpoints below 37.8°C1 whereas combustible liquids have their flashpoints above 37.8C 100F.
Flashpoint of any given liquid refers to the lowest temperature, which the liquid must be exposed to for it to burn. At times, the liquid may have one or two flashpoints depending on how pure it is.
These flashpoints are usually used as a guide to assist in safety measures and in proper grouping of these liquids. They therefore cannot be used to classify whether the liquid is safe or not. This very low temperature changes liquid to vapor with a flammable mixture.
Accuracy is required when identifying the flashpoint of any given liquid. To attain this accuracy one should have a source of ignition like a burning matchstick or a candle, which can burn immediately the flammable liquid, comes to its boiling point.
One should not confuse the flashpoint and the auto ignition temperature. The auto ignition temperature is the point at which the temperature, which the liquid vapor, burns automatically without having exposure to the ignition source.
The flashpoint should not be confused with the fire point also, which are the temperatures at which the flammable liquid continues to blaze once it has been ignited. However, it is critical to note that both the flashpoint and the fire point are not dependent on the temperature of the source of ignition, usually above both the fire point temperature and the flash point temperature.
The point of fire describes the fuels, which are made of liquids and are very dangerous to human beings if not handled with care. The term flashpoint also applies to both flammable liquids as well as the combustible liquids. Each liquid has an air pressure, which is dependent on the temperature that liquid is exposed.
This implies that an increase in temperature directly leads to an increase in air pressure. As this vapor pressure goes up so does the absorption of vapor of the flammable liquid in the air. Therefore, temperature is the determinant of the absorption of the vapor of the combustible liquid by the air.
A particular level of concentration of the flammable liquid vapor in the air is vital to maintain combustion of that particular combustible liquid. It is important to note that this level of concentration necessary for the flammable liquid to maintain combustion is different for every combustible liquid.
The flashpoint of a liquid is the least temperature, which there will be enough concentrated vapor of the flammable liquid to catch fire when a source of fire is availed (Henri 39).
It is important to note that there are two key types of flashpoints measurement and everybody should be aware of them. The first one is the open cup type of measurement whereas the second one is the closed cup type of measurement.
The method of measurement referred to as open cup has a cup where the liquid that catches fire is put, exposed to heat and later liquid is put over a flame.
Measurements of flashpoint are taken from where the flammable liquid has reached on top of the flame. The highest flame achieved during those intervals and which coincides with the fire point is thereby taken to be that flashpoint of that liquid.
On the other hand, in the closed cup, a cup with the flammable liquid is sealed with a lid through which the source of ignition can be inserted. Closed cup methods is renowned for giving lower values compared to those of open cup because they provide an enhanced estimates of the temperature at which the vapor will come to the lower limit.
It is critical to note that the flashing point is an empirical measurement and it is not a basic parameter because the measurements vary with the equipments which are being used as will as the protocols and international standards which one ascribes to.
This is because; the test will be dependent on other variables such as the time in which the sample was allowed to go into the equilibrium, as well as the sample volume. Another variable to be put into consideration is whether the sample is stirred or not. Stirring the sample will certainly lead to lower flashing points because stirring will avail more vapor than when the substance is left unstirred. (Benedetti 23)
When correctly determining the flashpoint of a flammable liquid there has to be standardization as the process in which the flammable substances are measured according to standard test methods. These standard tests are very necessary to curb ambiguous tests, which at times provide weird flashing points when the right procedures are not followed.
Although there are already set flashing points as indicated in the table below anyone who wishes to conduct tests to determine boiling points should follow the rules set by the standardizing bodies. These bodies are different and their standards vary from country to country. The test methods recommended by these standardizing bodies state the kind of devices and apparatus used to carry out such experiments.
They also provide a guideline on the procedures that the person doing the test is going to follow, and the accuracy of that test as the expected result range, which should be seen by the individual doing the experiment.
The following are the main bodies to control these standards and the standards to deal with the flammable liquids, are the ISO Joint Working Group on Flash Point (JWG-FP), Flammability Section and the Energy Institute’s TMS SCB4 Flammability.
Combustible and flammable liquids do not burn by themselves and what happens is that it is the mixture of air and their vapor, which burns. For instance Gasoline which has a flashpoint of – 40°C (-40°F) is one of the flammable liquids.
Even at very low temperatures, it still produces vapor to form a combustible mixture with air. Another combustible liquid is phenol, which has a flashing point of 79°C meaning that it must be heated above that temperature so that it can mix with air to form a combustible mixture, which can be ignited.
Another issue, which must be discussed when writing a research paper on combustible and flammable liquid, is concerning the flammable or explosive limits. It is important for anyone handling these fluids to know their explosive limits.
This is because these combustible liquids are prone to explosions that are very dangerous if they are not taken care of. Explosion limits provide the range between the lowest and the highest concentrations of the flammable vapor in an air that will burn or explode.
There are two kinds of explosion limits. The first one is the upper flammable limit and the other is the lower explosive limits that are measured in percentages. For instance, the lower explosive limit of gasoline is 1.4% and the upper explosive limit is 7.6%.
The explanation for this is that there can be ignition of gasoline or burning can take place if exposed to the air when the level of concentration is 1.4 per cent. When it is in the air with a concentration of less than 1.4% it cannot catch fire.
Another critical aspect, which must be looked into when discussing about the flammable and combustible liquids, is the aspect of ignition temperature. One has to be aware of ignition temperature for him or her to have an edge in dealing with the combustible liquids.
The ignition temperature, which is also known as the auto ignition temperature, is the point at which the flammable and combustible liquid ignites itself without any source of ignition such as spark or flame. It is similar to the explosive limits that are health hazards.
Whereas some of these flammable liquids have got a very high ignition temperature others have got very low ignition temperature such as ethyl ether whose auto ignition temperature is at 160C(356F) and it may self ignite when passing via very hot steam pipes.
It is important to note that auto ignition temperatures are used as guidelines and not as determinants of what is safe and what is not safe. To avoid accidents and injuries brought about by the flammable and non-flammable materials all the necessary care and precautions should be taken to avoid dangers brought about by these liquids.
Safety Precautions in Handling Combustible and Flammable Liquids
The following are safety precautions, which should be adhered to when using flammable liquids because; failure to use some of these liquids implies forfeiting the many economic benefits that accrue to the usage of these flammable and combustible liquids.
The flammable and combustible liquids can be a fire hazard in that at normal room temperatures flammable liquids can give off enough vapors to form combustible elements in the air. This makes them a fire hazard. Flammable liquid therefore are entitled to be handled and stored with an extra care because; they burn very fast producing a lot of heat plus a black poisonous smoke.
The vapor produced forms a mixture that can catch fire under increased temperatures if the flashing point is very high. Therefore, liquids, which are hot, may bring about fire that resembles combustible liquids.
Combustible as well as flammable liquids form mist when they mix with air and results to fire whether the temperature is high or low if there is a flame nearby. Another challenge of handling these flammable and combustible liquids is that their vapors at times are invisible to the eye and they have to be detected by special apparatus.
These liquids also have a high of viscosity, which means that a small spill can cover a large area where they have been spilt. If proper caution is not taken to clean them up when they are spilt they can flow under the doors, to other rooms or buildings and in the course of their spreading they can easily catch fire if anyone ignites anything, causing a huge and unexpected damage.
These liquids even after cleaning the spill some of them can be absorbed by the wood or clothing, which makes them dangerous because the clothing certainly releases harmful vapor.
There is another aspect that makes these flammable liquids to be a fire hazard because they can flow from open containers in the form of vapor. They move slowly but consistently.
However, these vapors are heavier than air, if the ventilation is not enough to give them a chance to diffuse into the air the vapor from these combustible liquids can settle in the room and if anyone lights an ignition source such as flame will be surprised by the fire, which will emanate from such a building.
The fire and flashback happen even in situations where vapor originates from a liquid that is very far from the point of ignition.
Apart from the obvious danger of the flammable and the combustible liquids being a fire hazard there have queries as to whether these liquids could have a side effect on the body especially the skin. Information and various researches indicate that most of these liquids are not harmful to the body.
However, some of them could have an effect on the body depending on the particular liquid and the route in which the body has been exposed such as breathing the vapor mist, eye or skin contact, or swallowing the liquid. Some of these flammable liquids are corrosive.
Most of the people experience serious irritation on their skins if they encounter some of these substances when they are stored improperly.
One of such flammable liquid, which is known to be of effect to the body, is the diethyl carbonyl, isopropanol, or isopropyl. This liquid is colorless implying that it is not visible to the eye especially its vapor. This vapor moves to different places because; it weighs more than the air.
It is considered a mild depressant of human central nervous system. Breathing a concentrated amount of vapor of this gas leads to headache, nausea, drowsiness, incardination and even confusion. It is also irritating to the eye and to the respiratory track (Benedetti 34)
The following are the control measures for flammable and combustible liquids. Flammable and combustible substances are composed of liquids such as greases, tars, oil paints, as well as organic solvents.
The first control measure in dealing with these liquids is to do an assessment. If it is a company, which uses some of these gases or if it is as at home place. One has to do an assessment to determine the dangers posed by these gases as well as ensure that these fire accidents do not occur.
What an assessment does is to identify loopholes, which could be there in the process of using these flammable liquids. If it is painting oils, are they left in a store or in an open place? Are the containers open or closed? Which is the flaming point of the flammable liquids in that store?
Could there be any leakage in those stores and what should be done? A good assessment of the likely hazards and their control is vital in ensuring proper safety measures have been taken against possible hazards posed by these liquids.
Apart from the assessment some countries require industries and companies which use these flammable and combustible liquids to have an Activity Hazard Document which contain a description of the work done and the safety precautions to be adhered to when doing such kind of an activity. This shows that even the authorities are concerned about the dangers posed by the flammable liquids.
Another safety precaution, which is usually taken by organizations, which use or handle these flammable liquids, is that they should inform and train their employees regarding what they should do and how they should behave in case some accident happens.
When looking at the safety precautions to be put in place to handle this kind of chemicals, some of those, which should be looked into, are the ventilations. A fume hood should be made as a place where these gases are stored or left exposed.
This fume hood should be placed anywhere where these flammable and combustible liquids are placed in a manner, which makes them produce vapor, gases, or mists. Activities in structures with fume hood include distillation, blending, and spraying, heating and preparation of mixtures.
Another aspect as part of safety precaution, when handling these flammable liquids, is that of having the ignition control. This is ensuring that all likely sources of fire are under control. This includes taking care of the area where a flame or a spark might come from in the areas where the flammable liquids are used. Electric switches should be well guarded to ensure that they are not in contact with the flammable vapor.
Another precaution relates to personal hygiene and the body in general they involve ensuring that storage of food and consumption materials are kept in the designated places only.
Protective garments should also be worn when handling flammable and combustible liquids to ensure that the eyes and the skin are not exposed to this vapor, which is not safe to them. This means that one should wear protective eyeglasses as well as having a gas make to prevent inhaling these vapors.
A very important aspect in the storage of these hazardous substances is that the flammable and combustible liquids should be stored away from the sources of fire such as heat, sparks and flames. During storage, the combustible liquids should be stored away from the oxidizing acids and oxidizers. They are chemicals, which can vaporize the flammable liquids.
The store should have more than ten gallons of combustible liquids and they should be stored in an approved flammable cabinet. The cabinets for storing flammable liquids are made in a way to protect the areas around them from fire.
They can be positioned below the fume hood or they can stand-alone. Proper combustible cabinet is made of steel and it is equipped with doors, which lock themselves in a three-point arrangement.
The cabinets for storing flammable liquids are put in the laboratory during the time of construction and in the buildings as well as areas that provide ventilation. This helps to control vapors as well as bad smell and prevent internal surfaces from rust.
Normal household refrigerators and freezers are made up of electrical parts such as light bulbs, switches, and motors, which are potential sources of ignition. This indicates that they can be a cause of fire if they are exposed to the flammable vapors at any given time without precautionary measures.
To prevent these from happening the freezers and refrigerators used in the storage of flammable liquids should be designed by experts. They should have been designed, assembled, labeled and approved for the sole purpose of storing flammable liquids (Henri 19).
Flammable liquids such as ethanol can be moved from containers or tanks by applying the force of gravity through pipes and self-closing valves, which have been approved by the relevant authorities.
This process of transferring flammable liquids must be done in a manner to ensure that there is no liquid spilling from the pipes. In addition, the container and the nozzles must be electrically interconnected to prevent static charges, which can cause a spark.
Combustible or reactive substances should not be used to clean up or to absorb spilt flammable or combustible liquid. Materials such as paper towels should never be used in such activity. One should have the relevant spill kit to handle such spills (Benedetti 45).
In areas where there are combustible as well as flammable liquids, a shower is very important and should be available all the time. This is to ensure that in case an individual comes into contact with the liquids they can be in a position to wash off the liquid and in a situation where the skin or the eye have been in contact with the liquid, flush off the affected area for fifteen minutes or more.
The flammable liquids are of great use to the people in the modern society where they are used in everyday life either as fuel or for the purposes of making life easier. This implies that irrespective of the dangers, which the flammable and combustible liquids pose.
Those who will be in a position to handle them with the necessary care and precaution will certainly have an advantage. Sluggish handling of these gases is very risky not only to the property near where it is used but also to the humanity in general.
Therefore, those who will efficiently use these liquids will have advantage over those who will not take care of them. Those who will fail to use this energy in the right manner will do so at their own peril.
Benedetti, Robert. NFPA Pocket Guide to Inspecting Flammable Liquids. Oxford: Oxford University Press, 2005. Print
Henri, Martin. Flammable and Combustible Liquids Code 198.1 Flammable and Combustible Liquids Code. London: John Wiley, 1981. Print