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Why Do Jeans Smell (3 Common Reasons + Solutions)

Five pairs of fresh smelling jeans dry on a line outside
Do your jeans smell? It's time to sort that out!

Have you ever pulled a pair of jeans out of your closet only to discover they smell like your grandmother’s closet? Or are you all too familiar with the new jean chemical smell that makes you want to never wear them? If so, you’ve come to the right place. 

Jeans can smell bad because of the chemicals some brands use during production, mildew from storing in damp conditions, or sweat and sebum on dirty jeans. To get rid of the unpleasant odor, you can use household products like baking soda and vinegar for gentle cleaning power and fresh air and sunlight to dry and deodorize.

Below you’ll find the most common reasons for those nose-wrinkling smells and how best to remove them. 

3 Reasons Your Jeans Smell Bad

The three main foul odors on jeans are a chemical smell, a musty, sour smell, and a stinky clothes smell:  

Reason 1: A Chemical New Jeans Smell

Have you ever excitedly opened up the package you just got with new jeans inside only to be hit by a waft of a strong chemical smell? There are a couple of different reasons for this foul odor:

A Chemical Smell From Formaldehyde in Denim

Does formaldehyde sound familiar? Yup, the same chemical used to embalm bodies is on your new pair of jeans – yikes!

Most mainstream denim producers use formaldehyde to make denim last and stay wrinkle-free throughout production. Formaldehyde can cause dermatitis, a skin irritation that can also cause the skin to blister or flake off, so the smell isn’t even the worst part. 

The best way to avoid this smell is to buy from a sustainable denim brand like Reformation that doesn’t use harsh chemicals like Formaldehyde to make their jeans. 

A Chemical Smell From Harmful Dyes Used in Production

A lot of brands use harmful dyes like AZO dyes to make their jeans, especially black jeans. These dyes can leave a pretty nasty chemical scent and have been seen to release carcinogens that are easily absorbed by the skin. 

Again, buying from a sustainable denim brand that does not use AZO dyes is a great way to avoid the chemical odors and carcinogens altogether. 

Reason 2: Mildew Can Cause Your Jeans to Have a Musty Smell

If you’ve ever smelled a sour smell after pulling out a pair of jeans you haven’t worn in a while, you might be wondering how a folded-up pair of jeans could start to smell so bad.

Mildew is a type of fungus that grows in damp conditions and releases a musty, sour odor. While mildew isn’t as dangerous as other types of mold, airborne spores can still cause respiratory issues or allergic reactions, especially in more vulnerable populations like the immunocompromised, young, and elderly. 

If you’re in the habit of rushing the jeans drying process, mildew can start to grow rapidly, causing an earthy, stinky smell. You can prevent mildew forming by only putting your jeans away once they are 100% dry (check out our article on how to dry jeans fast if you need a few tips).

If you still notice the musty smell, check out your washing machine and where you store your jeans. An unclean, smelly washing machine can grow mildew and put the scent on everything it washes. 

Reason 3: Too Little (or Too Much!) Washing Can Cause Scents To Build Up

Sweaty man exercises in smelly jeans
Exercising in jeans? This could be why your jeans smell...

 If you’re in the anti-washing jeans camp, I’m right there with you. However, despite being the best way to make denim last longer, there is such a thing as taking it too far. Your washing habits (or lack of) can cause smells in a few ways:

A Buildup of Sebum Can Leave a Noticeable Smell 

Sebum is a waxy substance that your skin secretes to protect itself. Not only is it one of the most common causes of acne, but it also can be the source of your foul-smelling jeans. 

When it builds up too much, it can create a barrier woven into your jeans that attracts dirt and other odorous elements. Because sebum is an oily substance, it can be difficult to remove if there is too much built-up because water cannot penetrate it. 

Feeling the Heat? Sweat Can Also Cause Issues

Sweat combined with bacteria on your skin can cause a body odor smell in your clothes. If you do not wash your jeans after a day of running around town, your jeans can soak up the sweat and smells.

Wearing jeans made of organic cotton is a great way to prevent too bad of a smell. Polyester fabrics are proven to hold onto microbial odors longer and more intensely, so sticking to breathable cotton is the right move. 

From Laundry Detergent Build Up

On the other end of the spectrum, if you’re all about washing your denim, but still have an unpleasant scent following you around, it could be because of laundry detergent buildup. 

If you use too much detergent for the laundry load you’re doing, the water won’t be able to wash all of the laundry soap out, leaving some behind. This excess detergent then sticks to your fresh laundry, trapping smells in. 

Laundry detergent is mainly for stain removal, rather than scent removal anyway. Even scented detergents just mask smells. Using the proper amount or avoiding laundry detergent altogether will do more for stink odor removal.

6 Eco-Friendly Methods to Remove Bad Smells From Your Jeans

If you’ve just picked up a pair of jeans and immediately had to plug your nose, help has arrived! Here are the best ways to remove an awful smell from your jeans.

1. Remove Stinky Odor With Baking Soda

Handwashing jeans with baking soda to remove odors
Baking soda can make the world of difference to how your jeans smell

Baking soda is a more eco-friendly alternative to other household deodorizers like borax or heavy chemical detergents. It’s an incredible natural absorbent, so it will eliminate smells rather than mask them. 

There are two different ways you can use it deodorize your jeans:

For jeans that absolutely need to be washed, adding a pinch of baking soda and half a cup of white vinegar to the wash cycle will both deodorize and set the dye, so your jeans won’t fade. This is a great option for black jeans, especially. Avoid using warm water or hot water because those cause jeans to lose their shape.

You can also use baking soda without a full wash to get rid of the chemical smells from new jeans by soaking them in a mixture of cold water and baking soda. Make sure to rinse well afterward and then air dry

2. Castille Soap is a Great Way To Remove Unpleasant Odors From Your Denim

Castile soap is an eco-friendly cleaner made of vegetable oils and sodium carbonate that’s great for deodorizing jeans. 

Soaking jeans in a solution of Castile soap and water for about 30 minutes will remove smells without damaging jeans. Rinse them well to remove any buildup afterward. 

Some can be made with palm oil, so make sure you find one like this EWG verified Castile soap to avoid the nasty stuff. 

3. White Vinegar Can Banish Musty Smells From Jeans

White vinegar is another great household deodorizer for jeans that will not remove dye from dark or black jeans. Combined with a little baking soda, it’ll remove detergent buildup and trapped smells very quickly.

If you’re having a mildew problem, white vinegar is especially great to use because it’s acidic enough to kill mold. Either soak your jeans in a solution of vinegar or spray the inside of your washing machine and wardrobe. 

4. Try Deodorizing Jeans With Oxygen Bleach

Oxygen bleach, a mix of sodium carbonate (a naturally occurring chemical) and hydrogen peroxide, is a great way to deodorize smelly jeans.  It’s environmentally friendly, safer to have in your home, and won’t stain your clothing as chlorine bleach will.

It will remove all smells from your jeans, including chemical smells, but it’s especially great at removing mildew. 

To use, just dissolve a bit into a tub of cold water and soak your jeans for about 30 minutes. Make sure to rinse well to avoid product buildup. 

This oxygen bleach is climate pledge friendly, so it has many sustainability certifications showing a low impact on the environment. It’s also a U.S. Environmental Protection Agency Safer Choice certified, so you know it’s not harmful to have in your home.

5. Lemon Juice is a Natural Deodorizer For Smelly Clothes

Lemon slices on wood chopping board
Lemons are a great natural option for cleaning your denim

If you’re looking to both deodorize and add a fresh scent to your jeans, lemon juice is a great natural option. However, it should not be used on black jeans or dark jeans because the acidity can cause them to fade. Also, it should be completely rinsed out before putting them outside to dry or it can cause damage to the denim fibers.

You can either mix freshly squeezed lemon juice and water in a spray bottle and lightly mist the inside and outside of your jeans. Or you can soak your jeans in a tub with lemon juice and water. Again, make sure to rinse completely before drying in the sun. 

6. Jeans Still Stink? The Sun and Fresh Air Are Your Friends

Clothing being air dried with blue skies and white fluffy clouds
Sometimes all you need is a little bit of sun

One of the easiest and most effective ways to both deodorize and reduce fungal contamination in your clothing is with sunlight. While you can get UV benefits by placing your jeans in front of a sunny spot inside, it’s even better to hang your jeans outside for both fresh air and sunlight. 

Prevent bad smells from even starting by air drying your jeans outside after every wash. If you notice a mildew smell, put all of your jeans in the sun for a day to get rid of the bad odor right away. Use that time to clean your wardrobe with vinegar to prevent them from getting smelly again. 

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