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Created for Greatist by the experts at Healthline. Read more

Humidifiers are great for treating dry skin and colds. They’re also the perfect breeding ground for bacteria and mold. The nastiness that grows inside of them can be transferred into the mist that you breathe. Tl;dr: gross. Here’s exactly how (and when) to clean your humidifier.

In a pinch, you can clean a humidifier with just H2O and a scrubbing brush. For a complete cleaning, you need to take it to the next level.

Things you can use

  • water
  • white vinegar
  • bleach
  • hydrogen peroxide
  • clean kitchen towel
  • microfiber cloth
  • small scrubbing brush, like a toothbrush

Minerals in tap water can form a white, flaky residue inside your humidifier. That residue (aka scale) makes a great base for bacteria to grow. The Environmental Protection Agency (EPA) recommends using distilled water to reduce scale. If that’s too much of a pain, you can use tap water. Just don’t let scale build up.

You should also change the water daily to prevent stagnation. Stagnant water can grow bacteria, so keep it fresh.

Here’s a step-by-step process to get rid of any mold, scale, or general gunk:

Phase 1

  • Unplug your humidifier.
  • Pour out any remaining water from the tank and base.
  • Fill the tank with about 2 cups of white vinegar.
  • Fill the base with about 1 cup of white vinegar.
  • Swirl the tank so the vinegar touches every surface.
  • Let the base and tank sit for 20 minutes to loosen scale and dirt.

Phase 2

  • After 20 minutes, scrub it down with a small cleaning brush.
  • Lightly scrub the small parts, like the cap, with a brush and vinegar.
  • Use a cloth dampened with vinegar to get into the nooks and crannies.
  • Rinse the base and tank with water until the vinegar smell is gone.
  • Wipe the exterior of the humidifier to remove dust and dry the base.

Phase 3

  • Humidify to your heart’s content!

If you don’t have vinegar

Vinegar is the best option for regular humidifier cleaning. Other detergents may contain chemicals that can get into the air and your lungs. If you don’t have vinegar, you still have options:

  • Soak the base and tank with hot water. Let sit for 20 minutes.
  • Scrub thoroughly with a small brush to remove scale.
  • Rinse out with hot H2O (distilled is best).
  • Let dry completely.

A note on filters

Humidifiers with wicks or porous filters often have an antimicrobial coating. Vinegar and chemicals can break the coating down over time. Try using hot water instead.

Vinegar is great for getting rid of surface mold and scale. But if your humidifier is really dirty, you need to take it up a notch. A chemical disinfectant can kill off any lingering bacteria and mold.

Here’s how to disinfect your humidifier:

  • Pour out any water from the base and tank.
  • Mix 1 teaspoon of liquid chlorine bleach with 1 gallon of water.
  • Fill the tank and base about halfway with bleach solution.
  • Swirl so all inner surface areas are covered.
  • Let the base and tank sit for 20 minutes.
  • Rinse the base and tank thoroughly until the bleach smell is gone. You don’t want to breathe in these chemicals!
  • Dry thoroughly.

If you don’t have bleach, the EPA recommends using a 3 percent solution of hydrogen peroxide to disinfect your humidifier.

The first step in avoiding a grody humidifier is cleaning it on the reg. Give it some TLC once a week minimum. That might sound like a lot, but keeping your lungs happy is worth it.

Scale buildup can turn into white dust, which is caused by the minerals in water. White dust can get into the air and may irritate your respiratory system. It’s not necessarily going to kill you, but it can lead to health issues like coughing and colds.

More tips

  • Change the filter. Depending on use and type of humidifier, filters should be changed every 30 to 60 days. If the filter ever looks gross or starts to smell, change it.
  • Watch your humidity. If household humidity gets higher than 50 percent, it’s easier for bacteria and mold to grow. Buying a humidity monitor is a great way to know.
  • Keep it dry. If the areas around the humidifier are wet, it means the humidifier is up too high. Lower the level and do a quick wipe down if there’s excess condensation.
  • Dry storage. Once your humidifier has done it’s duty for the season, thoroughly wash and dry it before putting it away. Storing a wet humidifier is a recipe for mold.

You can avoid dry skin in the winter and have healthy lungs as long as you keep your humidifier clean. A weekly scrub down should do the trick.

Keep in mind, each humidifier is a little different. Refer to the manufacturer’s instructions for more details. Go buy a gallon of cheap vinegar and enjoy your mist sesh!