Have you ever wondered if real leather is flammable or combustible. Have you ever tried to burn a piece of leather and noticed that some “leathers” burn and others don’t. In this post i discuss all the properties of leather and evaluate just how fire resistant leather really is.
No Real leather is not flammable or combustible. Real leather, when ignited, smoulders slowly and glows for a long time and will eventually shrink and curl. It is considered relatively resistant to ignition as it has excellent natural fire resistance properties that allow leather to smoulder but not ignite.
If you interested in learning more about leather and what makes it ideal for fire resistance read on for more info. Leather is all around us as we use leather products on a daily basis. At any one time we have at least 4 leather products on ourselves or within our reach, for example: Watch strap, shoes, wallet, jacket, skirt, couches, bracelet etc.
It’s crucial to make sure that some leather items meet certain fire safety standards when it comes to fire resistance.
Why is leather naturally Fire resistant.
Leather is the skin or hide of an animal, whether it’s a cow, pig or reindeer etc. As it is a natural product we need to look at its composition and what that means for Fire resistance. Authentic leather is porous and made up of fibres composed of collagen as well as water and fats. Leather therefore has the natural ability to absorb and retain moisture. Leathers ability to hold and retain water greatly aids in its fire resistance.
Leather also has the ability to lose moisture if it’s not treated with conditioner on a regular basis. This will result in it drying out and cracking. Leather fibres shouldn’t be too loose or spaced too far apart. Its thickness also aids in making leather more fire resistant.
Vegetable tanning and flammabilty
The tanning process also adds to the fire resistance of leather, for example, vegetable tanned leather is more fire resistant than chromium tanned leather. Vegetable tanning involves using natural tanning materials like tree bark and various other ingredients. This process takes much longer as natural materials are used.
Chromium tanned leather is tanned with hexavalent chrome or trivalent which is a hazardous chemical that can hinder its fire resistance.
The ingredients or chemicals that are used in the tanning process can also be altered in such a way that they are replaced with fire retardants. A leather tanner would need to know this before beginning the tanning process in order to add in the correct ingredients to make leather more flame retardent.
Fire resistance of leather is an important factor to consider as it’s widely used in public transport. Seats on Aircraft, trains, buses or luxury cars all transport large groups of people and therefore need to meet specific safety standards to minimize dangerous fires.
The same goes for pubic buildings such as hospitals, hotels and retirement homes. Luxury cars use authentic leather for car seats and leather upholstery. There are strict regulations and guidelines controlling the make up of the leather used in the automotive industry. Motor companies spend millions on testing and improving their methods of fire prevention in the motor vehicles.
What happens if you burn leather?
When you burn real/ authentic leather it will not burst into flame or suddenly melt like plastic. Authentic leather has good natural resistance to fire, and will slowly begin to char and shrink when placed over a flame. When burnt, authentic leather smells a bit like burning hair……..which i’m sure we have all smelt before.
What temperature does leather burn/ignite?
Exposure of leather to a flame in the temperature range of 130-170 degrees celsius (277-338 degrees Fahrenheit) for several minutes does not cause any structural changes in real leather. Exposure to temperatures higher than 200 degrees Celsius (390 Fahrenheit) will result in pyrolysis. Pyrolysis – is the decomposition of a material due to high temperatures or chemical changes brought about by the action of heat.
According to studies conducted on veg tanned leather: leather ignites at around 212 degrees celsius (413 degrees Fahrenheit.) This does not mean that it bursts into flame suddenly but rather that it will begin to slowly smoulder and glow and will eventually char, shrink and crumble. Real Leather is therefore fire resistant for short periods for temperatures up to 200 degrees.
Can leather melt and what is its melting point.
Leather will not melt like plastic or ice which turns into water. Leather is fire resistant and has an amazing ability to withstand high heat. The chemical definition of melting point is when a solid turns into a liquid. eg. ice cubes turn from a solid into liquid water. Leather does not have a melting point as it can withstand high temperatures and does not change from a solid into a liquid. These high temperatures eventually cause leather to char and disintegrate via pyrolysis but it still remains in a solid state.
How to test if its authentic leather vs fake leather.
The best way to test is to burn a small sample piece and see how it reacts to a flame. If you hold a lighter under a small sample piece of the leather for about 15-20 seconds real leather will only char slightly. The leather will also smell like burnt hair which is another good indicator that it is real. This is called the real leather fire test.
Fake leather will burn rapidly and catch alight quickly when a flame is placed against it. Fake leather will also smell like burnt plastic. This is because it contains plastics which have a much lower melting point.
Faux leathers contain a variety of additives which, although make them cheaper and more affordable they also make them more flammable. They usually contain plastic and polyvinyl chloride (PVC).
Vegan leather can contain petroleum which is highly flammable. Burning Faux leather will result in carbon monoxide gas being released which is highly toxic.
Is leather Fireproof or Fire resistant?
It’s difficult to make anything that’s ever 100% completely fireproof. The definition of fire proof is something that is incombustible or non combustible and is not capable of burning or igniting. Leather is not fireproof because if burnt for long enough at high temperatures it will eventually succumb to combustion. This makes leather fire resistant but not fireproof as it can resist igniting for a certain length of time.
Welding jackets, welding aprons and welding gloves are fire resistant. Welding jackets need to be super heat resistant as the individual who wears these clothes will need to be protected from sparks and welding spatter. They are made of thick genuine leather and sometimes use a combination of kevlar stitching and cotton but are high performing items that keep the user safe and protected when used.
Leather aprons are fire resistant and are used by blacksmiths, welders and various other tradesmen for protection against high heat and sparks. Here is a link showing you and example of a leather welding jacket. Link to Amazon. Leather can be made more fire resistant by adding fire resistant chemicals during the tanning process. Leather that will be used in automobiles are treated with these fire retardant chemicals to ensure they comply with regulations.
Burning leather to create patterns is called Pyrography
Pyrography is a burning technique that is used on leather to make interesting patterns and detailed designs in leather. Specialist tools and heated electrical pen nibs are needed to burn these patterns into leather. If you would like to learn more about this art form have a look this post I wrote called – Pyrography the art of urning leather.
Is burning leather toxic.
Yes, burning leather is toxic as leather is tanned and dyed using a variety of different chemicals. When leather is ignited or burnt these chemicals are released into the atmosphere. Chrome tanned leather is especially toxic and shouldn’t be burnt as it contains chromium and formaldehyde. PU leathers are also made up of various compounds, plastics and chemicals and should not be burnt as they are harmful to you and the environment.
Care should always be taken when burning leather. Adequate ventilation such as open windows or doors should be provided so that fresh air is circulated in your workspace. Working or burning vegetable tanned leather is more suitable for pyrography as its tanned with natural tannins and tree barks and is therefore not harmful to humans.
Conclusion
That’s all the info i have for you on leather and its resistance to fire. Hope you managed to learn something new today and tune in for more information on leather at leathercrafttoolbox.com