5 Reasons Leather Smell Like Fish That Nobody Talks About

why does leather smell like fish

I have always been a fan of the rich luxurious smell of real leather whether they are installed on a car seat or jacket. Nothing simply beats that smell. But this is not what I have always experienced.

I have sometimes been disappointed and did not understand the reason behind some of my leather smelling like fish. So I set out to do research on why this happens and I’m happy to share with you all my findings.

So, why does leather smell like fish? Here are the reasons why your leather may smell like fish;

  1. The Leather May Have Been Tanned Using Fish Oil As Tanning Agent
  2. The Age Of The Leather Item
  3. Leather Items May Smell Like Fish Because It’s Not Genuine Leather
  4. Leather Will Smell “Fishy” If It Has Mold Or Mildew
  5. The Type Of Dyes Used For The Leather
  6. Sulfur Content In The Leather After Tanning
  7. The Type Of Glue Used For The Leather
  8. The Chemical Used In Tanning May Have Been Contaminated

To learn more about how the points I have mentioned above cause your leather items to smell like fish, keep reading this article.

Reasons Why Leather Smells Like Fish – The Details

There are a lot of things that could contribute to leather items smelling like fish. While only one of these reasons could be the main reason for the fish smell on your leather items, other circumstances might result from a combination of different factors.

1. Sulfur Content In The Leather After Tanning

When leather items are made from animal skin, they have a certain amount of sulfur content that is usually injected into the fibers of the leather from the chromium(III) hydroxide sulfate used during tanning.

Tanning is a chemical process the raw animal skin goes through before the raw animal skin becomes leather. There are various tanning methods that are normally used to turn raw skins into leather; vegetable tanning and chrome tanning – with the latter being one of the reasons why leather sometimes has a fish smell.

While this is not usually an issue with other types of leather, it can be a major contributor to the fishy smell coming from your leather items.

This is because sulfur reacts with oxygen and other chemicals in the air and creates a chemical compound known as a thiol. Thiol is the main reason why leather items smell like fish, so this definitely needs to be considered.

2. The Age Of The Leather Item

Another reason why leather items smell like fish is the age of the item. Over time, sweat and natural oil from our skin can get absorbed by our leather items.

When it comes to age, older items of leather are more likely to give off that fishy smell. This is because of the natural oxidation process, which simply means that chemical reactions between air and leather cause the smell.

As leather becomes older, it becomes more susceptible to the thiol compounds in general and can result in a pervasive fishy smell on the whole leather item.

So if your item is already old, there’s no need to worry about it somehow being contaminated with fish or how it was produced.

The older the item is, the higher chance there will be for chemicals to cause it to smell like fish because of oxidation. Simply!

But if it’s a new item of leather and you can still smell the fishy odor, there could be other issues causing this – which I will discuss with you in the rest of this article.

3. The Type Of Dyes Used For The Leather

Some leather items are dyed to give them a specific look. This is true for all leather items such as shoes, belts, bags, etc. The dyes as we all know give them great appeal and make them look unique.

But some of these leather dyes simply stink. I have come across leather items that smell like moldy bread or something else I can’t even describe. Even worse, there are some dyes that would even have the exact same smell as fish.

This is because the type of dyes used for leather items usually have high chemical content and can often give off a fishy smell. Also, this can result from the leather dye going bad or expired.

The way this happens is although leather dyes are made explicitly for the purpose of dyeing leather, they can also cause certain chemicals to be released that could react with the tanning agents in the leather.

But not all dyes smell bad though, so this is something that needs to be considered as well. To recap this point, leather items can smell like fish if it has been dyed, which might have a chemical reaction with the other compounds in order to create that odor.

4. The Type Of Glue Used For The Leather

Leather is often glued to other leather items. For example, the soles of shoes and heels are usually held together by an adhesive – which is made from a certain kind of glue.

But this adhesive might give off a fishy smell as well, depending on what type of glue is used.

This chemical compound is known as formaldehyde, which can cause a very strong odor that smells like fish – especially when the leather or glue has been heated up under high temperatures.

So if your new shoes smell like fish, it might be because of the glue used to attach them to the sole.

Let me sidetrack a little bit. Formaldehyde is a chemical compound that smells like fish because of its characteristic stench. It is used in various items such as woodworking, plywood, and even used to preserve dead bodies.

This chemical compound can also be found in some household items, such as joint cement or glues, pressed wood products like paneling, and fiberboard.

This chemical compound is also used to make some leather items, such as leather coats and shoes. The formaldehyde chemical compound prevents the growth of bacteria that can cause rotting in leather items, which can also cause odors.

But not all leather coats or shoes are made with formaldehyde because of its cheap price and has been banned in some parts of the world.

So if you are not sure about how your leather shoes were made, it is always best to check for formaldehyde or other chemical components that can cause a fishy smell.

5. The Chemical Used In Tanning May Have Been Contaminated

The chemical compounds used to tan leather items can also cause a fishy smell. Before we go any further, it’s best that you know some other reasons why leather is tanned in the first place.

The tanning process is used to preserve animal skin so that it can last for a longer period of time. This is done by chemically altering the proteins in animal skin, which can prevent it from decaying over a period of time.

Without these chemical compounds, the leather items will only be able to last for a few weeks or months before it starts rotting and decomposing.

But like I said about the fishy smell, it can also be caused by the contamination of some chemical compounds used in tanning.

The chemicals that are used in tanning leather items are usually made from chromium compounds, which can be found in metalworking or electroplating.

But these chemicals can also be contaminated with other compounds that can give off a very strong odor, such as ammonium sulfide.

And when these contaminated leather tanning agents get into contact with the animal skin, it can also cause odors that smell like fish.

So if you are not sure about the chemical compound used in tanning, it is best to check with the tanneries to find out what kind of chemical components were used in order for you to understand the root cause of the problem and know how to deal with it.

6. The Leather May Have Been Tanned Using Fish Oil As Tanning Agent

As you can tell by now, there are a lot of tanning techniques out there. One particular method I found known as oil tanning actually uses fish oil as the tanning agent to treat natural hides and skins of animals into leather.

Oil tanning is an old leather tanning technique and is usually done by submerging the animal skin in a bath of fish oil and other chemical compounds.

This method may not be used as often as other methods, but it is still used in some parts of the world.

This particular method has been known to produce leather with a very strong odor, which can make it smell like fish.

The strong odors are caused by the oils used in this particular tanning method because it is made from fish oil.

So if you recently bought some leather items and noticed a strong odor coming from it, there is a high chance that it was tanned using fish oil as the tanning agent.

7. Leather Will Smell “Fishy” If It Has Mold Or Mildew

One other reason why leather items can smell like fish is that it has mold or mildew. Mold and mildew are a type of fungi that can grow on leather items.

This is a very common problem with leather items, especially those that are stored in moist or humid places for a long period of time.

The presence of mold or mildew can cause the leather to rot, which is why it will start smelling like fish.

This is why it is best to check for signs of mold or mildew before storing your leather items. Also, you must at all costs avoid storing your leather items in a moist place.

This is because the fungi that cause mold and mildew can grow very quickly, causing your leather goods to rot within a few weeks.

So if you recently noticed that your leather items have started to smell like fish, it is best that you check for signs of mold or mildew.

However, if you are not sure about the presence of these fungi on your leather items, it is best to ask for help from professionals.

8. Leather Items May Smell Like Fish Because It’s Not Genuine Leather

Synthetic leather, also known as faux leather will sometimes smell like fish. This is because these types of leather are made from synthetic materials that have a distinct smell to it, which may not be a bad thing.

But this smell can sometimes cause the item to have a strong odor that smells like fish. This is because faux leather is made of chemicals that are derived from petroleum.

And since these chemicals have a strong odor, they can also cause the leather to smell fishy if it gets exposed to heat, body oils, sweats, or water for a long period of time.

So if you recently bought some faux leather items and noticed that they smell like fish, you can be assured that these are not made from genuine leather.

However, if you like the smell of your faux leather items and they don’t bother you, there is no need to worry.

Final Thoughts

We all have some sort of expectation as to how the leather items we buy or have at home should smell like. Whether you’re someone who is looking to buy a leather item or if you are an expert in the field, understanding why leather changes its smell or has a certain type of smell will go a long way to help understand how to deal with it.

Leather will often have strong odors that make it smell like fish because of chemicals used during tanning and storage conditions.

In this article, I detailed some possible reasons for how your leather may be smelling so strongly with a distinct odor that smells like fish.

If these explanations sound familiar, then there are steps that you should take immediately to get rid of the bad odor from your animal skin goods before they start rotting away!

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