How to properly clean your humidifier and keep mold at bay

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You can use products like dish soap, white vinegar and hydrogen peroxide to clean your humidifier.The benefits of a quality humidifier include moisturizing skin, fighting off allergens and even defending against dry lips and mouth, according to the Environmental Protection Agency (EPA). If you use one often, then knowing how to clean and maintain your humidifier regularly will ensure that it doesn’t grow mold and present health risks in the future.

I spoke with cleaning experts for their cleaning guidance and product recommendations.

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Since the inside of a humidifier contains stagnant water of varying temperatures and little ventilation, it’s susceptible to growing residue. “The biggest issues with humidifiers are the build-up of a slimy film in the reservoir, potential bacteria and mold growth, and mineral build-up,” says Melissa Maker, author and founder of cleaning site Clean My Space. “All of which can be pumped into the air you breathe.” Additionally, how you clean your humidifier may depend on the type, such as ultrasonic, steam, evaporative or impeller, which we explain more in our roundup of the best humidifiers.

Plus, it’s important to clean your humidifier so that you can actually benefit from using it, says Delah Gomasi, founder of Maid For You. “One of the things that hinders its performance is scale (mineral deposit) buildup which clogs pretty much everything from the misting plate and water reservoir to the filter and crevices within the machine,” he says. “Simply put, when scale buildup prevents misting, there is no humidification taking place.”

All of these products have at least a 4-star average rating from 500 reviews or more on Amazon.

$7.99AmazonThese reusable, absorbent cleaning cloths are well suited for many tasks, including cleaning the inside and outside of a humidifier. Plus, they’re machine washable.

10,086 Amazon Reviews$10.68$13.87AmazonNow 23% offHydrogen peroxide isn’t just for first aid purposes — it’s also great for household cleaning. This food-grade option is safe to use around the inside of your humidifier. Add some to a cloth or put some in a spray bottle to apply all over. Hydrogen peroxide has similar properties to bleach, but with much less toxicity, particularly at a low concentration.

4,976 Amazon Reviews$37.99AmazonThis absorbent paper humidifier filter replacement is compatible with most Honeywell humidifiers. It traps dust, pet dander, dirt and other particles, while also helping your humidifier to release fresh moisture into the air, according to the brand.

$16.99AmazonThis solution helps remove mineral deposits that typically build up in humidifiers filled with hard water. If you use tap water in your coffee makers or pots, you can use this descaler to clean those appliances too, according to the brand.

selectedselectedTested: The best air purifiers of 2026Tips for cleaning different types of humidifiersSince there are humidifiers that create mists in different ways (such as cool-mist and warm mists) some of them have parts that need to be cleaned that others don’t. Plus, some humidifiers require replacement filters.

“A humidifier should be cleaned at least once a week if it’s used regularly,” says Robin Murphy, president of cleaning company Maid Brigade. This helps prevent the buildup of bacteria, mold and minerals that can affect both the performance of the humidifier and the air quality in your home.” If you only use a humidifier every once in a while, such as when you’re sick, then it’s fine to clean it once a month, says Murphy. It’s important, however, to empty out the tank after each use and allow the parts to dry before using it again.

As Murphy mentioned earlier, not cleaning a humidifier can lead to mold and bacteria growth. This is a byproduct of stagnant water and moisture inside of a container with little to no ventilation. You should really only have water in the humidifier if you’re actively using it, otherwise keep it empty when it isn’t on.

While bleach does a good job of getting rid of bacteria and mold, Murphy doesn’t recommend using bleach or bleach-based cleaning products to clean a humidifier, unless it’s done with caution. This is because the residual smell can irritate the eyes and respiratory system, especially since the machine is releasing moisture into the air. If you do use bleach, use a small splash of it diluted with water and use the same method with white vinegar, rinsing thoroughly after.

At NBC Selected, we work with experts who have specialized knowledge and authority based on relevant training and/or experience. We also take steps to ensure all expert advice and recommendations are made independently and without undisclosed financial conflicts of interest.

I’m a commerce editor at NBC Selected, where I regularly cover cleaning topics and appliances. I’ve written about the best dishwasher detergents, steam mops, and carpet cleaners. I’ve also written guides on how to clean grout, garbage disposals and coffee makers. I spoke with two cleaning experts for their guidance to write this story.

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Cory FernandezCory Fernandez is a commerce editor for NBC Selected, and an authority on all things food, cooking, kitchen, home, and general lifestyle.

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