Why Does My Mattress Smell?

A new mattress can have a slight scent on delivery day, which is normal, safe, and should dissipate within 24 hours. However, some new mattresses can have a strong chemical odor due to off-gassing, which can cause irritation in people with chemical sensitivities or respiratory conditions like asthma. There are ways to speed up the off-gassing process, such as unpacking the mattress outside or in a well-ventilated area and placing bowls of water mixed with baking soda or activated charcoal around the room to help absorb the smell. An old mattress can also have an odor due to sweat, body oils, allergens, and spilled drinks. To get rid of the smell, you can sprinkle baking soda on the mattress, let it sit, and then vacuum it upbut if the smell persists, the mattress may have mold and mildew growing inside it and may need to be replaced.

Mattress odors don’t contribute to pleasant sleeping experiences. The smell of a new mattress can be irritating to your airways, not to mention make you anxious about what is it exactly you’re inhaling. The smell of an old mattress can be disconcerting for different reasons.

Read on to find out what causes various mattress odors and what you can do to get rid of the stink.

Why does my new mattress smell?

New mattresses may have a slight scent when you first get them. For instance, mattresses that are made-to-order and arrive fresh from the factory may have a slight smell on delivery day. This type of new mattress smell is normal and is simply the smell of new materials. It’s also completely safe and should dissipate in about 24 hours. If your mattress is made from eco-friendly materials, then you don’t have to worry about this scent being caused by toxic chemicals.

On the other hand, some new mattresses can have a strong chemical odor due to off-gassing. Off-gassing is what happens when volatile organic compounds (VOCs) leak out of upholstery materials and mattress foams into the air you breathe. Common VOCs include such fumes as formaldehyde, toluene, chlorofluorocarbons (CFCs), benzene, trichloroethane, and perfluorocarbons.

Most off-gassing that’s linked to modern mattress materials has not, to date, been proven to be harmful. However, it has been shown to cause irritation in people with chemical sensitivities or respiratory conditions like asthma. Some people also report feeling nauseated or dizzy from the smell.

How long does the new mattress smell last?

If your mattress is eco-friendly, the smell of the new materials should dissipate within 24 of arrival. When it comes to off-gassing from mattresses that contain chemicals, the smell might last a little longer. Exactly how long the smell will last depends on the type and density of the foam, the ingredients it contains, and how the mattress is packed.

Many modern foam mattresses come vacuum-packed and boxed, which makes them easy to ship but may cause them to smell more upon arrival. That’s because the mattress is rolled and wrapped in plastic; once it’s unsealed and starts to expand, the odors are released too.

How to get rid of the new mattress smell

While there’s no proof exposure to VOCs is immediately harmful, their effect is likely cumulative—so it’s a good idea to minimize your exposure to them. Here are some ways to speed up the off-gassing process and get rid of that irritating new mattress smell:

  • If you can, unpack your new mattress outside of the house and, if weather permits it, let it off-gas for a day or two outside.
  • If unpacking it outside isn’t an option, do it in a well-ventilated area—ideally a spare room—with all the windows open, and leave it there for a few days. You can turn on the fan to help speed up this process.
  • Place a few bowls of water mixed with baking soda (mix five parts water to one part baking soda) around your room to help neutralize the smell.
  • Pour some baking soda onto the mattress, leave it there for a couple of hours, then vacuum it up.
  • You can also help neutralize the smell using activated charcoal. Just like with baking soda mixture, place bowls of charcoal around the room (or under the bed) to help absorb the smell.
  • If you need to use your new mattress before it stops off-gassing, cover it with a mattress protector to help prevent the chemical smell from spreading. You may smell the off-gassing every time you remove the cover to wash it, but the smell should dissipate over time.

Keep in mind some odorless chemicals can still be off-gassing without you being able to smell them—so the longer you can let your mattress air out, the better.

Can an old mattress smell?

An old mattress can have an odor as well—for different reasons. Over time, your mattress absorbs sweat, body oils, allergens, and generally, anything it comes in contact with. It remembers all the spilled drinks and all the accidents from back when your now sixth-grader was a freshly diaper-less toddler who used to come to snuggle in bed with you.

Not to worry—there are still things you can do to get rid of the smell. Here too, baking soda is your best friend. Simply sprinkle some on the mattress, let it sit for 30 minutes to two hours to help neutralize the odors, and then vacuum it up. You can also open all the windows and turn on the fans to let the mattress air out or leave it out in the fresh air and sun for a day or two.

If even after deodorizing and cleaning it the bad smell persists, then the culprit could very well be mold and mildew growing inside your mattress. Unfortunately, there’s no way to get rid of these, so your best next move would be simply to get a new mattress.

Time for a new mattress? Check out these eco-friendly options from Saatva

Saatva Classic Innerspring Mattress

Our flagship luxury mattress is expertly engineered with coil-on-coil construction for durability, a layer of memory foam for enhanced back support, and a cushiony Euro pillow top for extra comfort.

Contour5 Mattress

Luxurious body-hugging feel and pressure relief with 3” of ultra-premium, high-density 5-lb memory foam.

Zenhaven Latex Mattress

Natural latex responds to every curve for pressure-free support and responsive comfort. Natural latex is supple, resilient, and durable, for the ultimate in elevated sleep. (It's naturally hypoallergenic too.)


Why does my mattress smell musty?

That musty mattress smell in the morning is caused by the build-up of sweat, dust, and skin particles. In addition, when we sleep we release carbon dioxide into the air, which then gets trapped in the room and absorbed by our mattress. To help prevent (or remedy) this, make sure to air out your bedroom every day and wash your sheets regularly too.

Is it normal for a mattress to smell?

It’s normal for most new mattresses to have a slight scent on delivery day. If your new mattress is eco-friendly, the smell is simply due to the freshness of the materials and will dissipate after 24 hours. For conventional foam mattresses, the off-gassing will take a bit longer.

Do mattresses smell over time?

A mattress can start to smell over time because it absorbs sweat and body oils, pet dander and other allergens, and generally, anything it comes into contact with, such as spilled drinks and accidents. It’s a good idea to always use a mattress protector to minimize the contact of the mattress with your skin or any liquids.

How do you air out a mattress?

You can air out your mattress by leaving it outside for a day or two (in good weather) or in a well-ventilated room with all the windows open and fans turned on.

Find your new mattress at Saatva

Saatva offers a wide range of mattresses that are made to order with eco-friendly materials and delivered factory fresh. That means they’ll never off-gas in your home.

All of our mattresses come with a 365-night home trial and lifetime warranty. Take our mattress quiz when you’re ready to find your perfect mattress match.

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