This blog post will give you an explanation of whether a fire extinguisher can get rid of fingerprints through five subtopics. Starting with the basic information on what a fire extinguisher is, the blog gives you information on the purpose of fire extinguishers, how to handle them and their types. By the end of the blog post, you will understand if a fire extinguisher will get rid of fingerprints.
Will a fire extinguisher get rid of fingerprints?
No, a fire extinguisher will not get rid of fingerprints. In fact, fire extinguishers, especially powder type ones are used to enhance the fingerprints so that they appear more clearly. This helps in identifying and studying the fingerprint better.
Fire extinguishers and their purpose
For a fire to occur, there must be three essential elements, without which fire cannot occur. These elements are oxygen, fuel and a heat source. The reaction among these elements is the reason why fire occurs.
In certain situations, fire can become out of control and result in an emergency situation. In this case, a fire control device like a fire extinguisher must be used to put off the fire. Usually, a fire extinguisher will contain a mix of chemicals or gases like carbon dioxide or nitrogen in a compressed form.
Fire extinguishers are designed in such a way that they can be easily held, hence they have a handle with a trigger attached to the cylindrical body. When the trigger is pushed, the extinguisher released the media from within in order to put off the fire. Although there are some fire extinguishers that are non-cylindrical, it is not very commonly used as cylindrical ones.
The diagram of a typical fire extinguisher is shown below. (Image credits given in the reference section)
Types of fire extinguishers
There are different types of fire extinguishers that can be used for the various categories of fire. First, we need to know the classes of fires, only then we will be able to choose the correct type of fire extinguisher to put off the fire. The fire extinguishers must be appropriately labelled according to the class of fire to avoid confusion.
The different classes of fire and their sources are given in the table below:
|Class of Fire||Source of fire|
|Class A||Combustible solids (paper, wood, etc.)|
|Class B||Liquids or gases that are flammable (hydrogen, methane, etc.)|
|Class C||Electrical fires|
|Class K||Cooking fires (vegetable oils and animal fats)|
The various types of fire extinguishers are:
- Carbon Dioxide Fire Extinguishers
- Foam Fire Extinguishers
- Powder Type Fire Extinguishers
- Wet Chemical Fire Extinguishers
- Water Type Fire Extinguishers
Carbon Dioxide Fire Extinguishers
These type of fire extinguishers are commonly used to put off Class C type of fires i.e., electrical fires. It is very safe to use carbon dioxide on such fires as it does not conduct any electricity. Additionally, they can also be used to put off Class B type of fires i.e., fires due to flammable liquids or gases.
The mechanism of carbon dioxide fire extinguishers is that the carbon dioxide completely displaces the oxygen which aids the burning process. By moving the oxygen which is a crucial fire element, the fire can be easily put off. These extinguishers are one of the simplest type of fire extinguishers as it does not leave behind any residue.
Foam Fire Extinguishers
These type of fire extinguishers are commonly used to put off Class B type of fires i.e., fires due to flammable liquids or gases. Additionally, they can also be used to put off Class A type of fires i.e., fires due to wood, paper, textiles, etc. These type of fire extinguishers should never be used to put off electrical or kitchen fires. This is because foam conducts electricity and it can be extremely dangerous if used on such fires.
The mechanism of foam fire extinguishers is that when the foam is released from the extinguisher, it fully wets and cools the surface of the source. When the foam comes in contact with the source of fire, it also creates a shield between the flame and the fuel and thereby aids in putting off the fire.
Powder Type Fire Extinguishers
These type of fire extinguishers are commonly used to put off Class A, Class B and Class C type of fires. Therefore they are also known as ABC extinguishers. These type of fire extinguishers are quite versatile and safe, which is why they can put off different classes of fire. Typically such extinguishers are often used to put off fires from flammable metals.
The mechanism of powder type fire extinguishers is that the fine powder (usually ammonium phosphate) released behaves like a blanket around the fire and effectively displaces the oxygen. By doing so, the intensity of the fire slowly reduces and it is completely put off when the oxygen is fully displaced.
Wet Chemical Fire Extinguishers
These type of fire extinguishers are commonly used to put off Class F type of fires i.e., due to cooking fires. Additionally, they can also be used to put off Class A type of fires i.e., fires due to wood, paper, textiles, etc.
The mechanism of wet chemical fire extinguishers is that liquid mist released from the extinguisher completely wets and cools the surface of the source. Secondly, a reaction between the source (vegetable oils and animal fats) and the liquid mist results in a soapy material that acts as a barrier between the fuel and the fire. This helps in putting off the fire fully.
Water Type Fire Extinguishers
These type of fire extinguishers are commonly used to put off Class A type of fires i.e., fires due to wood, paper, textiles, etc. Such extinguishers should strictly be used for Class A fires and should never be used to put off electrical or kitchen fires. This is because water conducts electricity and it can be extremely dangerous if used on such fires.
The mechanism of water type fire extinguishers is that the water when released, completely wets and cools the surface of the source. The fuel also begins to cool and the fire begins to mellow down before it is fully put off.
How to handle fire extinguishers
Fire extinguishers are usually handled with the help of a technique called “PASS”. PASS is the abbreviation for Pull, Aim, Squeeze and Sweep. But before using the PASS technique a few steps must be followed, they are:
- The nearest fire alarm must be turned on and the fire brigade must be summoned immediately after the fire breakout is observed.
- Safely evacuate people in the direction which is away from the fire, so as to avoid danger.
- Choose the correct type of fire extinguisher and release the media from using the trigger of the fire extinguisher using the PASS technique ( explained below).
- Always keep the fire extinguisher at a distance while releasing the media.
- In case the fire extinguisher is fully empty and the fire is still not put out, immediately evacuate the area for your safety.
For releasing the media from the fire extinguisher with the PASS technique, use the following steps:
- The first step is “Pull”. In this step, the pin should be pulled so that the seal breaks.
- The next step is “Aim”. In this step, the hose should be aimed at an angle in such a way that it points towards the bottom of the fire source and not the top.
- The next step is “Squeeze”. In this step, the trigger must be squeezed so as to release the media.
- The last step is “Sweep”. In this step, while squeezing the trigger, move the extinguisher in a sweeping motion (sideways) from the bottom of the fire. Continue the sweeping motion until the fire is fully put off.
- Repeat the above three steps if the fire is still not put off.
Effect of fire extinguishers on fingerprints
It is commonly believed that it is difficult to retrieve fingerprints in case of a fire. For example, any theft or burglar incident that happens during a fire break out can be determined by studying the fingerprints. Although the fingerprints may not be as clear, there are ways to enhance the fingerprints in order to find the source of theft or burglary.
One of the interesting ways to enhance fingerprints is via a fire extinguisher. Especially the powder type fire extinguishers, when used on unclear fingerprints, the powder sticks to the oils or sweat in the fingerprint and thereby enhances it. This develops the fingerprint and makes it easier for the investigators to study it better. Therefore, a fire extinguisher will not get rid of fingerprints, it will only enhance it.
This article addresses the question “Will a fire extinguisher get rid of fingerprints?”
The article has given a detailed explanation of whether a fire extinguisher can get rid of fingerprints. The blog will also provide you with information on what a fire extinguisher is, its purpose, its types and how to handle it.
Please do not hesitate to comment on the above content or ask any questions in the comments section below.
Frequently Asked Questions (FAQs): “Will a fire extinguisher get rid of fingerprints”
Is the media inside the fire extinguisher poisonous?
Yes, the medium inside a fire extinguisher can be poisonous. The powder type fire extinguishers contain very fine chemical residues which are extremely irritating and poisonous especially when they enter the eyes.
Can a fire extinguisher be used as a weapon?
Yes, there are some situations where fire extinguishers can be used as a weapon. The force with which the media is being released from the extinguisher can injure an attacker. The media from the extinguisher contains chemicals that may enter the eyes or the nostrils of the attacker and can cause irritation.
Can a fire extinguisher make a person blind?
Yes, the media from the fire extinguishers can make a person blind. In the case of power type extinguishers, the powder released is very fine and when it comes in contact with the eye it causes severe irritation and there is a high chance of getting blind.
Can a fire extinguisher kill someone?
Yes, a fire extinguisher has the capability to kill someone. Especially if it is a carbon dioxide or a foam fire extinguisher, it will lower the level of oxygen in that particular surrounding which in turn causes suffocation. This will eventually kill a person if such a situation continues.
Can you put off any type of fire with a fire extinguisher?
Yes, all types of fires can be put off with a fire extinguisher. There are different types of fire extinguishers that cater to different sources of fires. Each type of fire extinguisher has unique media in it, which is specifically well known for putting of distinct sources of fire.
- www.usf.edu. (n.d.). Fire Safety – Fire Extinguishers. [online] Available at: https://www.usf.edu/administrative-services/environmental-health-safety/programs-services/fire-safety/fire-extinguishers.aspx.
- Wikipedia. (2021). Fire extinguisher. [online] Available at: https://en.wikipedia.org/wiki/Fire_extinguisher#Types_of_extinguishing_agents
- Koorsen Fire & Security (2017). What are the Different Types of Fire Extinguishers & Their Uses. [online] Koorsen.com. Available at: https://blog.koorsen.com/what-are-the-different-types-of-fire-extinguishers-their-uses.
- O’Hagan, A. (2018). A review of fingerprint recovery within an arson crime scene. Foresic Research & Criminology International Journal, 6(5), pp.315–325.