What To Do When Your Humidifier Is Leaving White Dust

Do you live in a dry-air region and have to use your ultrasonic humidifier often? If that’s the case, maybe you’re worried about your device producing white dust. 

This white dust forms whenever the mist, which was released into the air by your humidifier, dries up. The dried mist becomes this whitish dust, which looks noticeably different than the regular household dust and which ends up on your furniture, electric appliances, and other surfaces. 


Why Is My Dehumidifier Leaving White Dust? 

White dust from a humidifier

The white, fine dust produced by these convenient devices is a byproduct of minerals present in the water. As the humidification process occurs, these minerals turn into a fine mist. 

Later, as the mist dries, these minerals will cause it to turn into white dust. It will then settle on the surfaces around your home. 

White humidifier dust is a common occurrence in homes that use ultrasonic humidifiers and impeller humidifiers. These kinds of appliances humidify the rooms of one’s house through the steaming process. 

Water, which is present in the humidifier’s tank, is heated until it transforms into a gaseous state known as vapor. This vapor, which has the appearance of white mist, is then released into the dry indoor air. 

There, the minerals found in the steam start to fall down due to their weight and end up on surfaces such as tables and chairs in the form of whitish dust. 

Is This White Dust Harmful? 

Woman sneezing

In most cases, the white dust created by humidifiers is not a cause for serious concerns.  

However, the U.S. Environmental Protection Agency recommends using water with low mineral content in order to reduce exposure to white dust. People suffering from allergies, asthma, or any other respiratory conditions shouldn’t be inhaling white dust as it can easily exacerbate their problems. 

Keep in mind that this is just a recommendation. Neither the federal government nor the EPA has concluded that the minerals released into the air by these devices can be harmful. 

Therefore, the best course of action is to simply remain cautious and use distilled or demineralized water. 

When it comes to household items, on the other hand, there’s nothing to worry about – this whitish dust won’t damage your furniture or anything else in any specific way. It can be cleaned regularly just like the standard household dust. 

What Types of Humidifiers Don’t Produce White Dust? 

Not all types of these devices produce white dust. As I mentioned earlier, this kind of humidifier dust is mostly produced by the impeller and ultrasonic humidifiers – they use high-frequency vibrations to vaporize water into fine particles. 

Although very effective, ultrasonic humidifiers are quite notorious for this issue, particularly when used with hard water or any other kind of mineral-rich water. 

Cool mist humidifiers and warm mist humidifiers do not leave white dust. But if you still want to use an ultrasonic humidifier due to its efficiency, I would recommend using it with demineralization cartridges – these will prevent white dust from occurring. 

How Do I Prevent White Dust From Occurring? 

As I mentioned above, white dust can be dangerous to those suffering from respiratory conditions – it can cause lung problems and allergic reactions. 

Here are a couple of ways in which one can stop the formation of white dust around the humidifier and in the air: 

Use Filtered or Distilled Water 

Now that you know that this white dust is just high mineral content water turned into steam, it would make sense to start with the simplest solution. 

The easiest thing you can do to reduce white dust is to stop using hard water (hard tap water, to be more precise) and use filtered or distilled water instead. 

Unlike regular tap water, distilled water has a low mineral count. Obviously, this turns it into a much better choice for a humidifier and can make a massive difference when it comes to preventing the formation of white dust. 

When compared to distilled water, hard water can and will produce more white dust, so choosing the former option is the first thing you should do in order to keep your home free of white dust. 

Use a Demineralization Cartridge 

As it can trap minerals, a demineralization cartridge (or demineralization filter) can prevent the formation of white dust caused by those same minerals. It will stop them from going through a breakdown once they get released into the atmosphere. 

An important thing to mention here is that the efficiency of a demineralization cartridge doesn’t only depend on its design, but also on the mineral content of the water you’re using. 

Here are a couple of popular demineralization cartridges you may want to check out: 

HoMedics Ultrasonic 4-Pack

HoMedics Demineralization Cartridge

This particular demineralization cartridge uses ultrasonic filtration to “banish” hard water. 

The device effortlessly removes white dust that contains calcium, lime, and magnesium caused by dried mineral deposits present in the humidifier’s tank.

It also works as one of those handy air purifiers, as it successfully purifies and filters hard water and, in that way, ensures a clean and contaminant-free humidifier mist. 

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Pure Guardian FLTDC20

Pure Guardian Humidifier

Compatible with most humidifiers, this cartridge prevents the release of white dust or minerals into the air. 

As far as I’m concerned, its biggest selling point is the overall ease of installation. It only needs to be screwed onto the tank of the humidifier. 

Once installed, Pure Guardian FLTDC20 can prevent the white dust from forming for up to 700 hours. 

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Elechomes Universal 

Elechomes humidifiers filter

As its name suggests, this particular water filter is compatible with almost all brands of ultrasonic air humidifiers available on today’s market. 

To eliminate the white dust and purify the tank water, it utilizes advanced water-softening technology. 

When it’s in operation, this device creates a type of mist that’s ultra-fine and that doesn’t dry to dust so easily. 

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Frequently Change Water 

Regardless of whether you choose to go with tap water or distilled water, you will have to change it frequently. Not changing the water in the humidifier tank will cause it to pick up particles and minerals. 

It won’t take long for the mineral deposits to form inside the water tank – you can be sure about that. For that matter, always replace the water inside the humidifier tank with freshwater (instead of adding more dirty water) before running the appliance. 

Avoid Using Ultrasonic Humidifiers 

White ultrasonic humidifier

When it comes to white dust-forming humidifiers, the ultrasonic ones are undoubtedly the worst. The particles and minerals that are dissolved in the humidifier tank will be distributed around the rooms of your home when you use an ultrasonic humidifier. 

If you really don’t want to deal with white dust anymore, or if your home’s tap water is really hard, consider getting yourself a warm-mist humidifier or a cool-mist humidifier. 

Cool and warm-mist humidifiers are easy to clean and do not produce as much white dust. Just keep in mind that these kinds of devices require frequent filter replacing, although that shouldn’t be a trouble if having a not-so-dusty environment is your priority. 

Clean Your Humidifier and Regularly Change Its Filters 

Regardless of whether you’re using a cool-mist humidifier, warm-mist humidifier, impeller humidifier, or any other type of this device, make sure to keep its air passages free of dust. 

If you notice whitish dust inside or around your humidifier, make sure to loosen its fixtures and check for clogs. Do this at least once a week. 

The reason why you need to regularly clean your humidifier is due to the fact that any water sitting inside of it is bound to start collecting particles and minerals over time. And while you’re cleaning the insides of the device, make sure to also rinse its exterior in order to prevent a buildup of mildew and mold. 

I would recommend using white vinegar and mild dish soap (just a few drops of it!) for this task. You don’t want to use harsh chemicals – if you don’t manage to thoroughly rinse all the parts, these could become airborne and create even more health-related issues. 

In order to disassemble and reassemble the device in a correct way, make sure to consult the manufacturer’s instructions or the owner’s manual. 

Use a Water Softener 

As we’ve already established, the main culprit behind the mineral deposits in most humidifiers is hard water. 

In case you’re unable to obtain distilled water for your appliance, you could try reducing the number of minerals in your water by using a water softener. 

Although a more expensive solution, it won’t only help your humidifier but other appliances as well – such as the laundry machine. 

Keep Humidity Levels to Between 40 and 50% 

Electric humidifier

Another factor that can contribute to the formation of white dust in one’s home is the humidity level. 

To monitor it, you’ll need to get yourself a humidity meter. Once you notice that the amount of moisture in your home’s air exceeds 50%, make sure to turn the humidifier off. 

Keep in mind that higher levels of humidity increase the chances of white dust covering surfaces inside the rooms of your home. 

When Not in Use, Properly Store Your Humidifier 

Avoid storing away your humidifier when it’s wet or while it still has tap water or distilled water in its tank. 

Make sure to adequately clean all parts of the device before putting it away, as well as to change its demineralization cartridge and the filters. 

Consider Upgrading Your Humidifier 

If you’ve been using your humidifier for a long time – be it a cool-mist or steam humidifier – there’s a pretty good chance it’s time to replace it with a new unit. 

Using the same humidifier for years almost always leads to the development of mineral deposits that are incredibly hard to get rid of. It goes without saying that something like this also encourages the growth of bacteria, mildew, and mold. 

How Do I Prevent White Dust Using My Cool or Warm-Mist Humidifier? 

Humidifier on a floor

As stated above, not all types of these devices cause the appearance of white mist while they’re in operation. The culprits are impeller and ultrasonic units. 

These kinds of humidifiers aerosolize water as well as everything that’s inside of it, including bacteria and minerals. Moreover, they tend to turn the water molecules into mist through the use of high-frequency vibrations, which eventually leads to the appearance of the aforementioned white dust. 

In case you don’t want to use demineralized water but your region has hard water, consider getting yourself a warm or cool-mist humidifier. 

Both of these types of air humidifiers are phenomenal options for those wishing to add soothing moisture to the dry air inside their rooms. During the process of air humidification, these devices do not release white dust into the air. 

Unfortunately, there’s a disadvantage to using them – they tend to be quite loud. That is precisely why many homeowners still prefer to use ultrasonic models, as they’re whisper-quiet in operation. 

The Takeaway 

White dust is an issue encountered by most users of ultrasonic humidifiers. Unfortunately, if you don’t take care to prevent it, it can and it will get out of control. 

Before every use, make sure to run new water through your device – this will clean out any particles or minerals built up inside of it. Furthermore, cleaning the dehumidifier on a regular basis is bound to help prevent the buildup of mildew and mold – it’s a good practice regardless of what kind of humidifier you have. 

The white dust issue can be managed relatively easily as long as you stick to the tips I’ve listed above, so don’t hesitate to give them a try.