Are Humidifiers Safe?

Humidifiers are generally praised for soothing and preventing common conditions such as dry skin, cracked lips, a cough, and many more. And there are about a million and one articles out there that will tell you the many, many benefits a humidifier has to offer. Given the overwhelming amount of positive information and strong recommendations, it warms our heart that you’re still taking extra steps to ensure humidifiers are safe before bringing one into your home.

Are humidifiers safe? Yes, when used correctly and with proper maintenance, a humidifier is very safe and even works to improve the safety of your home by purifying and moisturizing the air.

Perhaps surprisingly, Americans spend an average of 90% of their time indoors, where the concentration of certain pollutants is often two to five times higher than outdoors. Indoor air quality directly affects our quality of life, and with the digital age keeping us inside at our computers more often, indoor air quality has never been so important.



Two Factors to Consider

When evaluating the safety of humidifiers, there are two factors to think about: 

  • Are they hygienic, and is the air safe to breathe? (Concerning humidified air).
  • Are they safe to have around the home? (Concerning the humidifier itself). 

Are they hygienic, and is the air safe to breathe?

When used correctly and with proper maintenance, yes, humidifiers are hygienic, and the air is more than safe to breathe.

Over humidified air (humidity level above 50%) is where we can run into potential problems and safety and hygienic concerns. High humidity isn’t just uncomfortable and sticky; it can be bad for your home and health. 

When the humidity level exceeds 50%, the air becomes stuffy and the excess moisture can cause condensation on your walls, furniture, and other surfaces. Bacteria thrive in warm, moist environments, and high humidity makes for their ideal breeding ground. The environment of over humidified air has a much higher likelihood of developing harmful bacteria growth, mold, dust, and worsening the severity of asthma and allergies

The safe and optimal range for humidity levels is between 30% and 50%. Low humidity (<30%) causes problems like dry skin, itchy eyes, and irritated nasal passages. High humidity (>50%) introduces the risks we just talked about. 

Some humidifiers have a built-in feature to measure and display the humidity level of their surroundings. Another way to monitor humidity is with a small device called a humidistat (or a “hygrometer”) readily available at home hardware stores, department stores, and gardening centers. 

The takeaway? Monitor the humidity level in your home to ensure the air stays in that healthy range of 30% to 50%. 

Are they safe to have around the home?

This question relates to the humidifier itself and prompts us to think about the space it will live in. 

Safety concerns can arise when small children or pets are running around the house. Not all, but some humidifiers add moisture to the air by boiling water and then dispersing the steam. This requires the unit to have a heating element that gets very hot when it’s in use. The safety hazard is the risk of the humidifier being bumped or knocked over, causing the boiling water to spill and potentially scold passersby. 

There are five different types of humidifiers, and a warm mist (steam vaporizer) humidifier is the only one that uses a heating element. If your humidifier is a warm mist humidifier, exercise caution and stay attentive when young children are in the room. This can also be a hazard for pets, specifically cats and dogs, who may knock the humidifier with their tail. 

The takeaway? Most humidifiers do not use a heating element or boiling water, meaning the worst that can arise from it being knocked over is spilled water. With warm mist humidifiers, it’s recommended to stay attentive, especially with young children and pets, or simply use your humidifier in a different and closed-off area.  

Safety and Maintenance With Your Humidifier

Humidifiers are more than safe when they’re used and cared for properly. Here are a few tips for using your humidifier safely and keeping it clean. 

Monitor humidity levels. You really want to stay on top of monitoring humidity to ensure levels stay within the healthy and recommended range of 30% to 50%. Low humidity causes problems, but so does high humidity. If your humidifier doesn’t have a built-in humidistat, hygrometers are highly affordable and definitely worth investing in. 

Use purified, distilled, or demineralized water - not tap water. Tap water contains minerals that can leave a residue within your humidifier. Any build-up of old and dirty particles, no matter how small, will be released back into your air, which is less than ideal for breathing and counterproductive to the concept of a humidifier. 

Don’t let water sit idle in the tank. Water should not be left in the tank in between uses. While one day probably wouldn’t hurt, it’s best practice to stay in the habit of emptying it after each use to avoid it ever being forgotten about. When not using your humidifier, empty the tank and leave the lid off to allow for air circulation. 

Clean it regularly. Don’t worry, cleaning a humidifier is much easier and quicker than one might think it would be. Sticking to a regular cleaning schedule ensures your unit is adequately sanitized and prevents a build-up of minerals, dust, dirt, or anything else we don’t want in there. It's very important to remember not to use chemicals when cleaning your humidifier.

Once a week, fill the tank with a mixture of half water and half white vinegar and run the humidifier as usual. Allow it to run for about an hour before turning it off, emptying the remaining liquid, and rinsing the tank to cleanse the residual. Run the humidifier one more time with fresh water for another hour before the next use. 

That’s it! Easier than you thought, right? 

Types of Humidifiers

  • Ultrasonic humidifiers (produce a cool mist with ultrasonic vibration)
  • Impeller humidifiers (produce a cool mist with a rotating disk)
  • Evaporators (use a fan to blow air through a wet wick)
  • Steam vaporizers (uses electricity to create steam that cools before leaving the machine)

Disadvantages and Preventative Measures 

If you don't rinse and replace the water each night, bacteria and fungi can build up leading to particles that can enter the lungs creating health problems. Moreover, although clean humidifiers can be a remedy for cold symptoms, dirty humidifiers can even affect healthy people potentially triggering symptoms similar to the flu.   

Additionally, even though dry air creates dry skin, high humidity can trigger the growth of bacteria, dust mites, molds and mildew. These allergens may cause respiratory problems as well. 

Be sure to check your filters or cartridges often, and change them according to the manufacturer's instructions.

To avoid or remove mold, clean your humidifier out every few days with water and vinegar or hydrogen peroxide

Safety First

We know you didn’t have to, but we’re so glad you’re taking extra steps to ensure the safety and well-being of your home and family. We’d do the same. 


Indoor Air Quality | EPA's Report on the Environment (ROE) 

Humidifiers: Air Moisture Eases Skin, Breathing Symptoms 

Dirty Humidifiers May Cause Health Problems | CPSC Publication 5046 

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