If mysterious, musty smells in your bathroom have you scratching your head, this article is for you.

Although occasional musty smells aren’t uncommon in bathrooms, persistent mustiness must be sourced out and addressed.

Here, you’ll learn the top causes of musty smells in bathrooms, their sources, and how to fix them using natural products and cleaning methods.

What’s Causing My Bathroom to Smell Musty? 

Mustiness in any room, including bathrooms, can usually be linked back to mold and mildew.

And what do mold and mildew thrive on?

Humidity and moisture, plus dust, dirt, and grime—ding, ding, ding! It's no wonder bathrooms are prone to mustiness.

So, why do some bathrooms get musty and others don’t?

Part of it is due to ventilation, the number of people using the bathroom (a single person or couple versus a large family), the design of the bathroom, and how often it’s cleaned.

The good news is you can usually eliminate musty bathroom smells with minimal effort and natural products.

Related reading: How To Get Rid Of Musty Smells In Your House

Why Should I Avoid Toxic Chemicals in My Bathroom? 

Bleach is the typical first line of defense for treating mold, mildew, and musty bathroom smells.

In fact, most people keep a spray bottle of harsh bleach tile cleaner for this very purpose (and nearly choke on the fumes every time they use it).

However, did you know the EPA no longer recommends bleach for mold removal? It’s true, and this goes for bathrooms too.[1]

Here’s why: Although bleach is effective at killing surface mold, it does not reach sub-surface mold, making it ineffective in the long term.

Bleach also introduces moisture to the area, which feeds subsurface mold, resulting in a vicious cycle.

Plus, bleach is a highly toxic VOC. It is linked to hormonal disruption, pregnancy complications, poisoning, eye, lung, skin, and throat irritation, increased risk of infection and disease in children and adults, microbiome disruption, and a host of other issues no one wants in their lives.[2][3][4]

So, what should you use instead?

Hydrogen peroxide.

This low-tox cleaner breaks down to hydrogen and oxygen, is completely environmentally friendly, and works wonders on mold and mildew, especially when used with a natural soap-based cleaner.

We’ll discuss more alternatives to harsh bleach-based cleaners in the following sections.

Learn more in: 7 Best Bleach Alternatives For Bathroom Cleaning 

Natural Ways to Get Rid of That Musty Smell 

Get rid of musty bathroom smells naturally in just three steps:

1. Identify the source
   
   1. Common sources of musty smells include shower curtains, drains, bathmats, towels, tile, grout or sealants, and plumbing leaks under vanities.
      
2. Clean it up using natural products that remove and then kill mold and mildew.
   
3. Maintain humidity and cleanliness using proper ventilation and human-safe cleaning products.

Let’s break this down a bit more.

Increase Ventilation

If you’re unsure where the musty smell is coming from, increasing ventilation is a perfect place to start.

Be sure everyone uses the bathroom exhaust  fan and/or opens windows (if applicable) when bathing.

If your bathroom doesn’t have a window, open the door and open the window closest to you to help blow out the humidity.

If your bathroom has poor ventilation (which is not uncommon), running a box fan  or dehumidifier is a great way to control humidity during and after bathing.

Related reading: Better Air Means Better Health: Enhance Your Immunity by Improving Indoor Air Quality

Control Humidity

Humidity is inevitable in bathrooms. However, the best ways to control it are:

1. To increase ventilation, using the methods above and a dehumidifier when needed.
   
2. To keep things dry between bathing.

You can do this by wiping down or squeegeeing your shower, tub, and shower doors after bathing and opening up shower curtains so they can dry thoroughly. Keep your exhaust fan and or box fan on for 20 minutes after using the tub or shower.

Also, after bathing, remove wet towels and washcloths from the bathroom.

Wet towels left in the bathroom, combined with poor air circulation, can quickly lead to stagnant, musty conditions.

Throw the wet towels and washcloths in the dryer for a few minutes or hang them out properly in designated areas, such as the back porch, or consider letting them dry outdoors on sunny days.

Check Your Shower Curtain, Shower Liner, And Shower Doors

Shower curtains are notorious for harboring mold and mildew, and must be cleaned regularly.

The best defense against mold and mildew buildup is to dry your shower curtain after use by pulling it fully open, increasing ventilation using the bathroom exhaust and/or a box fan for quick drying, and cleaning or washing it every one to two weeks.

If mold and mildew have already set in, follow this bleach-free cleaning process:

1. Remove the shower curtain from the rod and scrub away as much mold and mildew as possible using Branch Basics Bathroom, plus a sprinkle of Oxygen Boost.
   
2. Rinse and apply 3% hydrogen peroxide to the remaining mold/mildew. Allow to dwell for 30 to 60 minutes.
   
3. Place directly into the washing machine (if you have a synthetic curtain, use a Guppy Friend bag to avoid releasing microplastics) with Branch Basics Laundry Detergent or Laundry Solution plus a scoop of Oxygen Boost and run on hot.
4. Remove, let dry in the sun, and re-hang.
   

What’s the best shower liner to use to prevent musty smells?

First and foremost, always opt for a natural cotton, linen, or hemp shower curtain paired with a good shower liner.

Linen shower liners are a better natural fabric option than cotton and hemp because linen dries faster and has natural wicking properties.

PEVA and EVA shower liners are also eco-friendly, odor-free, and do not contain phthalates like PVC-based vinyl shower liners and curtains.    

If you have shower doors, be sure to check the sealants. If not applied and/or cured properly, they can become hotbeds of mold.

If you see mold in sealant, remove it using an Exacto knife (and wear a mask and gloves!), clean the area thoroughly with Branch Basics Bathroom, Oxygen Boost, and 3% hydrogen peroxide, and re-seal.

Related reading: How To Clean Your Shower Naturally: 6 Tips

Give Your Drains A Good Clean

Many people have jumped to wild conclusions about mold-infested bathroom walls or ceilings, only to discover their drains were the problem.

This can come as a huge relief, as musty drains are easy to fix.

Here’s how to clean your drain to remove that musty smell:

1. Remove any clogs using a coat hanger or clog removal tool.
   
2. Pour a few tablespoons of baking soda down the drain.
3. Follow with a cup of vinegar or lemon juice.
4. Let it fizz for about 10 minutes.
5. Rinse with hot or boiling water*.

*If you have PVC pipes, skip the boiling water in favor of hot tap water.

This should be enough to get rid of most musty smells.

If the smell persists, pour about a cup of 3% hydrogen peroxide down the drain and let it sit for 15-30 minutes. Then flush with fresh, warm water.

You can also use a combination of Borax, vinegar, and salt as outlined in Natural Drain Cleaners: 5 Safe Options For Your Home.

Address clogs and clean drains regularly to prevent musty drain smells from coming back.

Wash Towels And Bathmats Regularly

Towels and bathmats can collect mildew fast, especially in poorly ventilated bathrooms and hot, humid climates.

To avoid this, hand towels and bathmats should be properly dried after bathing, hand towels should be changed regularly, and everything should be laundered at least once per week, or more in very humid climates.

If bathmats are a problem, consider bamboo or wooden bath mats, which can be wiped down after use.

Check For Plumbing Leaks

Even a slow plumbing leak under a sink or vanity can create a mold problem fast.

Check under sinks, vanities, behind toilets, and around shower heads.

Plumbing leaks can also happen behind walls, resulting in a musty smell. However, unless there is visible mold on the wall, a professional assessment is usually needed to identify these types of leaks.

Once the leak is identified, it should be fixed immediately, and the area should be remedied safely, with larger jobs left to mold abatement professionals.

Related reading: How To Prevent And Minimize Damage From Water Leaks

Clean It Up & Prevent Musty Smells With Branch Basics 

Branch Basics Bathroom, All-Purpose, and Oxygen Boost are excellent human- and environmentally-safe options for helping remove mold and mildew on shower tile, shower curtains, and grout, as well as to prevent future problems.

For removal of everyday mold and mildew on bathroom tile or grout:

1. Spray grout lines liberally with Branch Basics Bathroom.
   
2. Sprinkle with Oxygen Boost. Wet the Oxygen Boost with a spray of Bathroom solution.
   
3. Scrub with a toothbrush or scrub brush.
   
4. Let it sit for 1-5 minutes (the longer the better).
   
5. Rinse or wipe off with a microfiber cloth to remove dirt, grease, grime, and the mold.
   
6. As with germs, just cleaning with soap and water removes the mold. 
   
7. Optional: Finish by spraying straight hydrogen peroxide on the grout lines (add a spray bottle cap directly to your hydrogen peroxide bottle to make this easy), and let dry.

Regular cleaning with Branch Basics Bathroom, All-Purpose, Oxygen Boost, and Streak-Free will also prevent soap scum build-up, which is a favorite food of mold and mildew.

Learn more in: How To Clean Your Bathroom Naturally With Branch Basics 

Maintain A Regular Cleaning Schedule

As mentioned previously, mold and mildew need two things to thrive:

1. Moisture/humidity
   
2. A food source (dirt, grime, soap scum, etc.)

This is why regular cleaning is essential.

For bathrooms, we recommend wiping down the tub or shower after use with a towel or squeegee and cleaning the entire bathroom at least once a week, or more, for highly trafficked bathrooms.

Find inspiration and practical tips in: How To Set A Stress-Free House Cleaning Schedule You Can Live With

What Does Mold in My Bathroom Smell Like? 

Mold in the bathroom can smell musty, earthy, or dirty. 

It can also emit no smell at all, so using your eyes and nose is essential to finding it early.

Clean Homes Without The Toxic Chemicals

All the hype about the dangers of mold exposure in homes can cause us to jump to dramatic conclusions when musty smells arise.

However, more often than not, it’s a simple issue of minor mold/mildew build-up in drains, shower curtains, sealants, tile grout, or on towels or bath mats caused by poor ventilation, excess humidity, or slow leaks.

You can easily eliminate most musty smells by following the advice above.

If this isn’t enough, do not hesitate to call a mold-testing company. Mold can grow inside walls and in places that are impossible to spot with the naked eye.

If you’re looking for a natural, human-safe, and environmentally-friendly bathroom cleaning line, consider Branch Basics.

Our all-in-one cleaning system uses just one MADE SAFE-certified, cruelty-free, plant- and mineral-based, biodegradable Concentrate plus Oxygen Boost to clean your entire bathroom and replace every cleaner in your home.

Just add the designated amount of Concentrate plus water to make bottles and bottles of All-Purpose, Bathroom, Streak-Free, Foaming Wash, and Laundry Solution.

Our Premium Starter Kit contains the Concentrate, Oxygen Boost (laundry booster, bleach alternative, and stain remover), and refillable glass or plastic bottles—everything you need to get started.

To learn more, see: How To Get Started With Your Branch Basics Kit.

Shop Branch Basics Starter Kits Here.

References:

1. https://www.epa.gov/mold/mold-remediation-schools-and-commercial-buildings-guide-chapter-1 
   
2. https://www.cdc.gov/niosh/reproductive-health/prevention/disinfectants.html 
   
3. https://pubchem.ncbi.nlm.nih.gov/compound/Sodium-hypochlorite#section=GHS-Classification 
   
4. https://oem.bmj.com/content/72/8/602%20