4 Ultrasonic Humidifier Dangers You Need To Know

Among all types of humidifiers, ultrasonic humidifiers are the most popular. Ultrasonic humidifiers have many merits that people love. For example, they disperse the cool mist, which is safer for kids and pets. They are so quiet that they will not disrupt your sleep.

However, some dangers related to it are easily overlooked. An ultrasonic humidifier can disperse bacteria, mold, and white dust into the air. It can over humidify the room and even cause electric shock. 

Don’t be agitated! Using an ultrasonic humidifier is generally safe. But you should take measures to prevent these potential risks.

Ultrasonic humidifier dangers: is it safe?

Unlike evaporative humidifiers that use the evaporation process, ultrasonic humidifiers work by breaking down the water into moisture particles through the vibration of a metal diaphragm. While this technology has many advantages, it also causes some adverse effects or potential dangers. 

I will explain these potential dangers in detail to help you understand why these dangers can happen.

1. Ultrasonic humidifiers can disperse bacteria and mold spores

Ultrasonic humidifiers don’t have heating elements to boil water and produce steam. When you knock over it accidentally, you will not get burned. This is the reason many parents of infants choose it. 

However, it also means that the impurities in the humidifier’s water tank can get into the air along with the water droplets.

The water tank is humid and warm, which can quickly become a petri dish for molds and bacteria. If you don’t clean the device regularly, these microorganisms will survive and thrive in the tank and go out when the appliance is on. 

The airborne bacteria and mold spores will always hunt for a new residence and are inhaled into our airways and lungs, causing infections and other respiratory issues. 

Some people use humidifiers to relieve their respiratory conditions, but using an ultrasonic humidifier may worsen the situation if it is not maintained regularly.

2. Ultrasonic humidifiers can expel white dust

If you fill the tank with tap water or other types of water that can contain minerals, the dissolved minerals will settle down and form white dust that is discharged into the surrounding air and lands on the furniture. 

The white film is not toxic, but the white film on the furniture can extend our cleaning time, and when it enters our body, it may trigger some reactions as well. 

Evaporative humidifiers don’t produce white dust as the wick inside filters out the minerals.

3. Ultrasonic humidifiers can over humidify the room

This danger could apply to most types of humidifiers. Humidifiers don’t have a built-in humidistat, and even if it has it is not as accurate as you imagine. 

The ideal humidity level is somewhere between 35% to 55%. If you keep the device running for too long, it can make the air become over humidified. 

An environment that is too damp can cause dust mites, mold growth, and other issues that can pose health risks to your health.  

4. Ultrasonic humidifiers can cause electric shock

electric shock

Although the probability of occurrence is very low, you should still be careful.

While most humidifiers today will shut off automatically when they run out of water, they are still electronics, and any electronics have the danger of electric shock. 

Beyond that, humidifiers can malfunction and start to leak at some point, causing dangers if you don’t deal with them carefully.

How to avoid risks related to ultrasonic humidifiers

Even though there are a few dangers to using ultrasonic humidifiers, there are many ways to prevent them. Ultrasonic humidifiers are safe in most cases, and you don’t have to worry about that overly.

Clean the device regularly 

The stagnant water is the best place for mold and bacteria growth. Meanwhile, the mineral buildup can form scale and white dust. But it takes time for them to accumulate and thrive. 

If you change the water every day and remove the deposits one or two times a week, they will have fewer chances to breed or clog the ultrasonic unit.

Add distilled water to the reservoir

Except for forming white dust, minerals provide nutrients to microorganisms. If you can reduce the minerals in the water, you can reduce many risks related to ultrasonic humidifiers. You can either place some cartridges into the tank or change the type of water you fill.

Distilled water is the best since it doesn’t contain any minerals, meaning that you can clean the machine easier, and the machine is not likely to produce white dust as often as before.

Use a hygrometer

If your ultrasonic humidifiers don’t have a built-in humidistat or its result is not reliable, you can purchase an extra hygrometer. 

These hygrometers are usually affordable, but they can help you monitor the indoor humidity level to know how long it should be on.

Check the machine regularly

To avoid any electric shock, you should examine the device regularly. If you find any leaks or glitches, fix them or purchase a new unit.

Contact doctor immediately

Whenever you feel uncomfortable while using it, you should contact your doctor as soon as possible. This is even more crucial for people with breathing problems such as asthma or COPD. 

Don’t hesitate to ask for help from your doctors.


Ultrasonic humidifiers are generally safe, but there are a few dangers to avoid. People using it are more susceptible to mold and white dust. It can get the room too wet, risking your health again. 

Luckily, you can avoid most of them by regularly cleaning the base and tank and putting in distilled water. Anyway, these methods are standard for maintaining any type of humidifier. 

When comparing ultrasonic humidifiers with evaporative humidifiers, ultrasonic humidifiers are quieter and have better appearances. It is a better choice for people who care about aesthetic appeal and better sleep. 

You don’t have to dispose of your ultrasonic units because of these potential dangers. Just keep them in mind and prevent them from happening. You will be OK.

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Liz Yang is the founder of Airsmartly. She has been working at home for a few years and realizes that the performance of the HVAC system plays such an important role in our life. She has tested a lot of products in person, like humidifiers, air purifiers, dehumidifiers, and ACs, and wants to share tips about using or troubleshooting these products with you. Her uncle is an HVAC expert with over 30 years of experience in the field, and often offers assistance when she is unsure how to handle a situation. He is also in charge of reviewing the articles on this site.

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