What Does Mold Smell Like?

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What does mold smell like? This is a great question and one that is very popular in search engine results. In fact, if you were to run a query right now, you would see the following questions asked:

  • Can you smell mold?
  • Does mold smell?
  • What does indoor mold smell like?
  • What does mold in walls smell like?
  • What does mold smell like in a bathroom?
  • What does mold smell like in carpet?
  • Does mold smell sweet?
  • Does mold smell like body odor?
  • Does mold smell like ammonia?
  • Does mold smell like urine?
  • Old house musty smells
  • And about 100 more variations.

Clearly the topic of how mold smells is a confusing one since it doesn’t smell the same from person to person. If you were to ask a stranger on the street what mold smells like you likely will get a response akin to “a damp basement,” “musty,” or “an old house.”  While these descriptions can be accurate, they only really scratch the surface of what mold can smell like.

Rising mold smell - do you know what mold smells like?

But Wait – Is That Really Mold That You Are Smelling?

In some cases, yes. In most cases no. What you are actually smelling are the mycotoxins produced by mold. (If you aren’t sure what mycotoxins are all about, I suggest you read my post on Mycotoxins before finishing up this post.)

Mycotoxins typically produce rather pungent odors that range from everyday odors that are out of place to nearly indescribable odors. For example, stachybotrus which produces trichothecene has been described as smelling like cat urine. I personally got a whiff of cat urine in my moldy home from time to time. But mainly, our house smelled like burnt chorizo. That is literally the only way I can describe it. Super odd odor that never went away and something I could never find the source of. I wrote it off to our house holding onto cooking odors until I actually began to smell like grease all the time. I digress…

Some mycotoxins are known to produce a specific smell but there are quite a few “common” smells that can be attributed to any type of mold and mycotoxin. Let’s look at some specific mold smells first and then dive into the “all-inclusive” odors.

Stachybotrys and its mycotoxins have been described as smelling like:

  • Cat urine
  • Mowed grass

Aspergillus and its mycotoxins have been described as smelling like:

  • Cooked Fat
  • Oil

Chaetomium and its mycotoxins have been described as smelling like

  • Musty
  • Earthy

Non-species specific odors include:

  • Acetone
  • Acrid
  • Ammonia like
  • Baking Bread
  • Camphor Like
  • Cigarette Smoke
  • Cinnamon
  • Damp
  • Dirty Socks
  • Exhaust from a lawnmower
  • Fermented Alcohol
  • Greasy
  • Herbaceous
  • Locker Room
  • Maple Syrup
  • Meaty
  • Musty
  • New Drywall
  • New Paint
  • Nutty
  • Old Cheese
  • Peppery 
  • Rotting Wood
  • Sour milk
  • Stale sweets
  • Wet Dog
  • Wet Rocks
  • Wet Socks

As you can see, mold can emit many different types of odor, just like it can come in many different colors and textures.

So, how do you know if what you smell is mold and not just the occasional odd  smell in your home?

  1. If aromatic mold is present, the smell will not fade no matter what you do to ventilate the room. Mold’s odor is persistent.
  2. If you feel like you’re breathing in stale or damp air, even when the windows are open, you likely are being suffocated by the smell of mold.
  3. If you’re dealing with irritation or constant sneezing when you’re in a specific room, this can also be a sign of a moldy smell.

It is important to note that a lot of mold and mycotoxins have no discernible smell at all. Just because you can’t smell them, does not mean they are not there. It’s essential to detect and get rid of mold immediately because the human body can adapt to the smell of mold pretty quickly. This was the case in my home. I stopped smelling the weird smells because I was so used to them.

What Exactly Causes Mold To Smell?

Back to those mycotoxins. The smell associated with mold derives from mycotoxin gasses, which are called microbial volatile organic compounds (MVOC). Some molds and mycotoxins produce different MVOCs depending on conditions such as how much moisture is available and what material the mold is growing on. However MVOCs are only produced at all when mold is actively growing. This is because MVOCs are the waste products created by mold as it grows.

The Difference Between A Musty Smell and A Moldy Smell

Moldy smells and musty smells are similar in nature and both are caused by the presence of mold or mildew.  (Read more about the difference between mold and mildew in this post).

The main difference between a musty smell and a moldy smell is that musty odors are not nearly as strong and often come on during times of heavy rain or during a change of season. A musty smell from mildew is often very easy to isolate to the area where the mildew is growing whereas the moldy smell might waft all over the house and not be easy to isolate.

Is The Smell Of Mold Harmful?

The smell of mold is often noticed before its presence is made visually evident. This is where the problem lies. By the time you smell the mold, your health may have already been impacted.

MVOCs can cause symptoms like headaches, nausea, dizziness and fatigue. MVOCs may also irritate the eyes and the mucus membranes of the nose and throat. Our understanding of MVOCs is still limited but the consensus is that they do have the potential to cause significant health issues.

Beyond that, if you smell mold it also means you are inhaling mold spores and absorbing them through your eyes and skin. This can cause a wide variety of health issues as well.

What Should You Do If You Think You Smell Mold?

If you suspect mold is present but do not see mold or have an active leak, the next step is to test for mold. You can choose from a variety of DIY options or hire a professional mold inspector.

Since the smell is a sign that mold is actively growing in your home your next step after testing is to remediate the mold problem as soon as possible.

Can You Still Smell Mold After Remediation?

Hopefully not. The remediation process is designed to remove and replace all moldy materials as well as “scrub” the air. While it is not a 100% guarantee that every mold spore or mycotoxin will be removed, a reputable remediation company will remove and clean as much of your home as possible which in theory will eliminate any moldy smells as the mold should be gone.

Besides Remediation, Are Their Easy Ways To Get Rid Of The Mold Smell?

The only way to get rid of the mold smell is to remove the mold. Air fresheners, disinfectant sprays, household cleaning products, candles, incense, and potpourri may temporarily cover up the smell but they won’t get rid of it because you are not addressing the source of the smell.  In addition, they can release there own set of toxins and chemicals which can compromise your health further.

The EC3 Candle has been proven to remove mold spores and mycotoxins in the air and as such, removes the moldy smell. I have used these personally and can attest to their effectiveness. You still need to address the mold problem but the EC3 candles can definitely help in the short term.

There are also some mold remover sprays that do work to some degree.

Have you ever smelled a moldy smell? What did it smell like to you? I am already adding to this list based on your comments.

A version of this post first appeared on Hybrid Rasta Mama. It has been significantly updated for inclusion here.

Collage of water damage ceiling, the smell of mold, and a moldy wall

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24 Comments

  1. Cheryl Krebs says:

    I just had a mold air test and it can put very low for mold yet I know I have it and I’m sick from it and it’s from my clothing . I had a mold apt and I brought my clothing in my car to my daughters apt and I contaminated my car and my daughters apt and now my new apt . The mold tester told me it might be Psychosomatic. I know he is wrong I know it is in my clothing and I can’t get it out I have tried every detergent and bleach and after a few days the smell comes back I’m literally have to get rid of everything I own this is the worst nightmare I’ve had in my entire life and it is affecting my health my grandsons health my daughters health my cats health and no one believes me what do I do obviously an air test is not the answer

    1. I am so sorry you are going through this Cheryl!!! An air test is not the best way to determine if you have a mold issue. I am going to send you an email.

      1. what’s the best way for mold

    2. lady on Facebook and InsTa gram said borox??

  2. Bought a house 1st part of November and started getting sore throat in December. Have had sore throat since except while on vacation my throat was getting better. Came home and sore throat again almost immediately. Now that it has warmed up there is also a strong odor in the house that is Hard to describe. Seems mostly in one room, but spreads out in house. Thought it might be off gassing from new furniture but removed it to the garage and still have strong smell in house. Could it be mold somewhere? Hoe do I find out? Sick of being sick!

    1. Hi Becky! This is certainly suspicious. Sore throat was one of my constant symptoms when I lived in my moldy house. I would suggest you order and run this test: https://moldhelpforyou.com/ermi-test/ You can do it yourself (very easy) and you get the results fairly quickly. This is an affordable starting point in determining if you have a mold issue anywhere in your home. Please let me know if you have questions!

  3. Jenifer, I would love some help/advice. 9 years living at current residence, Ive realised something is wrong. I did have a bad leak 5 years ago, but some of my symptoms started from beginning. Mainly Inflammation of body openings, eyes, throat, ear pressure, back passage. Concentration is poor and sleep is not at all refreshed. Frustrating as my family/friends think I’m unstable. It’s hard to move as I’m in receipt of benefits.

  4. rachel frampton says:

    My dad noticed that there is mold in his bathroom, which is why he’s thinking of hiring a service that may remove it. Well, thank you for informing your readers that mycotoxins are the common scent that the molds produce. I’m glad that you were able to share here that this type of scent smells like cooked fat or oil.

  5. Bought a very old house with evidence of past moisture issues. While working on it (prior to moving in) noticed I couldn’t work inside more than a couple hours without sore throat, headache, hard time breathing. I observed light purple color coming through bathroom linoleum and fuzzy black growth in the basement ceiling joists (looked like a mustache hanging from the wood). I made sure there were no continuing water problems, removed 90% of the old drywall, soaked the entire house with Decon30 before installing new drywall and painting, put in dehumidifiers to run constantly on each level that are showing humidity in the 20-30% range, but after about 4 months living here, I’ve started smelling a faint cigarette smell. I have never smelled it before (3 years of ownership) and wonder if its mold that is releasing as the wood floors or joists are getting dry to the bone?

    1. It very well could be! Mycotoxins can smell like just about anything. Normally odors related to mold and mycotoxins come on slowly. This sounds like what you have been noticing.

  6. This post helps a lot. My family and I have been sick since purchasing a home in 2018. We did find mold and contacted our insurance company. However, the contractor had the audacity to say that is wasn’t enough mold to make me sick so he thinks it’s something else wrong with me. My thought is it doesn’t take a hundred bees to sting someone for them to have a reaction or go into anaphylactic shock. Why would it take an enormous amount of mold to have a negative effect on someone. Everyone’s body responds differently. We have had 3 mold tests and they all came back with several types of mold. Since leaving the house we have drastically improved. I would really like help or advise on how to get doctors to listen and how we can detox from this poisoning. At this point, any advice helps.

    1. Hi there! So sorry to hear you are going through this. And the contractor should be kicked into the next zip code. Sigh. Most doctors are still not mold savvy and truly have no training on how to deal with patients who have been exposed to mold. They really won’t have any idea on how to advise you to detox. Unfortunately, you will likely need to seek care out of pocket. I am happy to refer you to some budget friendly and knowledgeable practitioners who work remotely with patients.

  7. Rubi Otero says:

    My house literally smells like cat string pee, I’m tired of it especially at night, any help?

    1. Hi Rubi! Is the smell stronger at night? Have you done any mold testing at all yet?

      1. Do certain mycotoxins, like those produced from Stachybotrys smell stronger at night?

        I’ve been in a new home for a year. I moved out of two homes due to mould toxicity. I have been chronically sick for 3+ years. In my new house my health is slightly worse than it was at my best – after over a year of detoxing – but it isn’t as bad as living in previous mouldy flats. However, there is this faint stale dusty smell that most people don’t notice. Also when my partner stays with me she gets itchy eyes and has to be on antihistamines when she’s here. Today she told me her clothing smells like cigarettes. I don’t smoke.

        Thanks for your help.

        1. Hi Conor! Anecdotally there is evidence to suggest that the smell of mycotoxins is stronger at night because of the decrease in air flow. As the air becomes more stagnant the smell is more obvious. As we move about during the day, it gets wafted around and would appear not to be as strong. So yes, this is very possible. My clothing smelled like burnt grease and yet I wasn’t filling my home with burnt grease. So your girlfriend is not at all imagining that smoke smell.

  8. This post helped me confirm my suspicion that I was exposed to mold at a motel room I booked in Houston near NRG stadium.

    The first room they offered me smelled strongly of urine like a truck stop bathroom.
    The second one didn’t smell as bad but the air was musty/stale/damp. Needless to say, we didn’t stay the night. However we did stay for a few hours, and after the small amount of time we stayed my throat begin to burn and my lungs started to feel heavy. I also started sneezing a lot. I’ve been sick for over a week now.

    Thank you for this post! I learned so much. Now off to contact the city’s health department.

  9. Last month I moved out of a building that had signs of prior water damage and I got sick there. We moved into a relatively new apartment building (4yo) last month.
    Ever since moving in, I smell a chemical that I cannot compare to anything. Before I moved in, the apartment was freshly painted and the bedroom has a new carpet. Initially, I was getting headaches and felt burning in my nose, but I air out daily and my symptoms are minimal if they occur at all however the smell persists.
    It’s been 5 weeks and it doesn’t seem to be going away. I smell it only when I enter the apt and within 30 seconds, my nose gets used to and I cannot smell it until the next time I enter the place. Generally, I’m feeling better now but I’m losing my mind over this mysterious smell.
    The maintenance checked for freon leaks etc and my air purifier shows excellent air quality at 4 pm2.5 when it’s running but even when it’s off, the air quality is still a couple points below 12 (pm2.5).
    I thought that if there was a mold issue, the air quality would be worse here.. secondly, I read that paint can release VOCs for months.
    Could you give me a piece of advice what I could do next to identify the source of the smell? I could wait and see but having very negative mold related experiences, not knowing gives me anxiety.
    I can add that there might’ve been oil paint used which cures longer because when I was wiping the bathroom door, the paint wasnt wet but felt somewhat soft if that’s a good way to describe it

    1. Hi Natalie! I would purchase an air quality monitor to see if it picks up anything else. It could be the VOCs from the paint especially if it was an oil based paint. Look into this monitor: https://amzn.to/3RpIc2c

  10. Alex Sutton says:

    This is great! We’ve been questioning if what we were smelling was mold for a while, but could never quite decide. After reading your blog and finding several similarities, we decided to just call a >mold remediation expert to put our minds at ease. Fortunately, it was just old smells lingering, but your information has definitely helped us be more aware and mindful of what we are smelling in our home. Thanks so much for sharing!

  11. we came back from vacations, went to take a shower, I turned on the hot water first and a horrible smell got out the shower, I let the hot water run for 10 minutes and took a shower. since then all the water tastes like moldy rotten wood . in the sinks bathrooms and kitchen. I have under the sink filters in the kitchen and a charcoal filter for drinking water, that I bring to the bathroom for brushing our teeth but I don’t feel like showering with the smelly water.
    please any solution?
    Monica