The pink substance in your humidifier is a bacterial, mold, or fungal growth. The bacteria Serratia marcescens, is the most common cause of pink residue inside humidifiers. The pink mold Aureobasidium pullulans, and the pink fungus Fusarium, can also grow in humidifiers, but these are far less common.
Humidifiers can be the best solution for dry air, but without regular maintenance, a pink substance can build up on the edges, bottom, or sides of the water tank, the outlet and even around the humidifier.
In this article, we’ll take you through the reasons why pink stuff appears in your humidifier, how to figure out which specific problem is yours, and how to remove it.
3 Possible Pink Problems In Your Humidifier
The pink residue or slime growing in your humidifier is not because of poor water quality.
In fact, the pink stuff in your humidifier is usually caused by a pink bacteria, although it can also be a pink mold or fungus. The pink slimy stuff grows because bacteria, mold and fungus love damp and dark places (which, you guessed it, is a humidifier).
There are three types of pink growths that can grow in humidifiers:
- Serratia marcescens (bacteria) – the most common cause
- Aureobasidium pullulans (mold)
- Fusarium (Fungi)
1. Serratia marcescens (Pink bacteria)
Serratia marcescens if often called a pink mold, although it is not actually mold.
While it looks a lot like mold it’s actually a bacteria and grows in places where you expect mold to grow (like bathrooms).
The pink color comes from prodigiosin, a pigment produced by Serratia marcescens.
Depending on how old the bacterial growth is it can range from pink to red. The older the growth, the redder it will look.
High humidity levels promote the growth of this airborne bacteria, but in reality it grows on surfaces that are regularly damp or wet, like a humidifier.
Other places you might have seen this bacteria are toilets, porcelain sinks, shower curtains, and tile grout in bathrooms.
When there is a lot of this pink bacteria, it gives itself away with an ammonia-like (or urine) smell
2. Aureobasidium pullulans (Pink mold)
Aureobasidium pullulans is a type of pink mold that starts as a pink growth, but can turn gray or dark brown later. After long periods of time it can turn a blackish red.
This is the most common type of mold that might be infesting your humidifier.
But is less common than the pink bacteria.
3. Fusarium (Pink fungi)
Fusarium is a type of fungus that can make a pink residue grow in your humidifier.
While fusarium is more common in our outdoor environment, like in the soil, one of the only places you’ll find it indoors, is in a humidifier. In fact, studies have shown that continuous use of a humidifier can provide ideal conditions for fusarium to establish.
If your residue is brown (not pink), Plentiful Air has a guide to help you remove and prevent it from building up in your humidifier available here.
How to Remove The Pink Germs From Your Humidifier
You can get rid of the pink stuff from your humidifier by simply cleaning it.
It doesn’t matter whether it’s the pink bacteria, mold or fungi. Cleaning and disinfecting your humidifier will remove all three of these germs.
Your humidifier needs to be disinfected (not just cleaned) because if any of the spores or bacteria remain, it will grow back.
To clean and disinfect your humidifier properly you can use:
- White vinegar
- Hydrogen peroxide
We recommend vinegar as it is better at killing spores.
Distilled White Vinegar
Vinegar is a natural disinfectant, and it will loosen any of the residues inside your humidifier while also disinfecting it. To clean the humidifier using vinegar:
- Unplug and disassemble your humidifier.
- Fill the water tank with water and add two tablespoons of distilled white vinegar.
- Let this mixture stay in the tank for 30 minutes. Swirl it around occasionally.
- Plug it in and let it run for an hour in the open air – NOT indoors.
- Then pour out the remaining water from the tank and clean the areas with pink residue build-up using a clean cloth or small brush.
- For deep cleaning of all humidifier parts, you can use full-strength distilled white vinegar. Make sure that the humidifier’s working part (motor and electrical components) don’t come in contact with vinegar, water or any other chemical, as it can cause permanent damage.
- Rinse all humidifier parts with clean water and leave them to air dry.
- Once all the humidifier parts are completely dried, it’s ready for use again.
Hydrogen Peroxide
You can use a 3% Hydrogen Peroxide solution to remove the pink residue from your humidifier, simply:
- Unplug and disassemble the humidifier.
- Pour 3% Hydrogen peroxide solution into the inner chamber and water tank. Do not pour any liquid into the air outlet.
- Close the lid and shake five to seven times. Then let the mixture sit inside for half an hour.
- Dump the solution from the water and tank, making sure that water does not flow into the air outlet.
- Gently rinse all components of the humidifier.
- Pat dry the water tank and base.
- Air-dry the humidifier for a day.
How To Prevent Pink Bacteria And Mold Growing In Your Humidifier
The best way to stop pink bacteria or mold from establishing in your humidifier is to limit the conditions that are favorable for its growth. Moisture control and improved airflow will helo reduce microbial growth.
Here are a few tips to prevent pink outbreaks in your humidifier.
1. Clean Your Humidifier Regularly (more often than you think)
Regular cleaning of humidifiers is the first and most important step in preventing microbial growth.
It guarantees that any spores that could have entered in the air intake or removed, and also that any mineral or dirt deposits that act as a food source for the germs are also removed.
You can clean the humidifier using vinegar and hot water once a week. Avoid using harsh chemicals as they might damage the humidifier.
Cleaning your humidifier regularly will not only prevent pink bacterial and mold growths but will also increase the life of your humidifier.
2. Discard the Water After Every Use
You should discard water from the water tank every day after using it.
Never let the same water sit in a humidifier for more than 48hours, as this will make it extremely hard for any type of microbe to grow.
3. Use Disinfectants
Using natural cleaning products like vinegar when doing your regular cleaning can lower the chances of germs growing in your humidifier.
4. Replace Filter Regularly
If your humidifier has a filter, it should be replaced every 30 to 60 days or as recommended.
5. Seasonal Start-Up and Shut Down
In case you need a humidifier for seasonal use only, make sure to disinfect it properly before storing and starting it up again.
To avoid pink growths, remove the tank from the base and empty all water to allow all the compartments to air dry. This will maintain your humidifier in good working condition.
6. Use distilled Water
Using distilled water instead of tap water is better as the tap water can promote mineral deposits and contribute to pink microbial growth.
7. Intermittent usage
Avoid using your humidifier continuously. Studies have shown that continuous use of a humidifier leads to a drastic increase in microbial outbreaks after 6 days.
Intermittent usage of your humidifier will help minimise the ideal growing conditions for bacteria and mold. Try to limit your usage to less than 10 hours per day.
Health Impacts
The moist environment of a humidifier provides a breeding ground for bacteria, fungi, and molds. If you don’t clean your humidifier regularly, it can easily become a cozy incubator for various germs, sending them out into the air with the mist and causing health issues.
The pink residue is not as hazardous to your body as black mold or other fungi; but, long-term exposure can raise serious health issues.
Children and older people are more prone to the allergenic reactions caused by pink bacteria and mold. In the same way, immunocompromised people are more likely to develop severe symptoms as their bodies can’t defend themselves from infections.
Pets can also show allergic symptoms if exposed to the pink substance.
According to the CDC, mold in general can cause many health problems with some of the more obvious symptoms including:
- Coughing
- Stuffy nose
- Burning eyes
- Skin rash
- Sore throat
- Respiratory distress
- Lung inflammation
Prolonged exposure to the pink residue can also cause hypersensitivity pneumonitis; a condition also named ”humidifier lung’‘. The significant symptoms of humidifier lung include difficulty in breathing, cough, and fever
Various forms of pink residue are highly infectious and cause the following allergenic reactions and illnesses.
- Serratia marcescens can cause various infections in the human body, particularly blood infections and also urinary tract and wound infections.
- Aureobasidium pullulans is an allergenic dematiaceous mold. It can cause skin and soft tissue infections, splenic abscesses, meningitis, and peritonitis.
- Fusarium mycotoxins show no apparent intoxication. However, ingestion, even in low amounts, can lead to intestinal impairment and disturbance in immune function. The WHO has even suggested Fusarium mycotoxins are neurotoxic – which means it can damage the brain.
Plentiful Air has more information on how humidifiers can influence your health available here.
Frequently Asked Questions
How Long Does it Take for Pink Mold to Form in a Humidifier?
Pink mold can develop within 24 to 48 hours of humidifier usage. Although, the level of microbes already present in your humidifier will determine how quickly a growth establishes. Discarding the water each day, and not running your humidifier continuously will help prevent pink mold from establishing.
Why Does Pink Mold Develop in Humidifiers?
Bacteria, fungi, and molds thrive in dark and humid environments, and are likely to develop in humidifiers because the surfaces are in regular contact with water. Humidifiers work by drawing water from the water tank and dissipating it in the form of mist, and dispersing any mold spores contained within the humidifier. The pink mold can also collect on the edges of a humidifier.
What Personal Protective Measures Should I Take Before Removing Pink Mold?
Before removing pink mold from a humidifier, it is better to wear personal protective equipment, including:
- Gloves
- Dust mask
- Safety glasses
Don’t forget to disinfect your PPE, after removing the pink substance.
Is Pink Mold Harmful?
Pink mold is harmful and a health hazard, particularly for sensitive people. It can cause respiratory infections, urinary tract infections, gastrointestinal issues, and skin irritation. Prolonged exposure can cause hypersensitivity pneumonitis, also known as ”humidifier lung’’. Symptoms of humidifier lung include difficulty in breathing, cough, and fever
Can You Use a Humidifier that has Mold?
Humidifiers that contain mold growths should never be used. Mold spores and mycotoxins produced by the mold are released into the atmosphere along with mist, and can cause respiratory infections and lead to serious health issues with prolonged exposure.
Can Mold Spores be Pink?
Mold spores can be pink, even if the mold is not. Pink mold colonies appear pink with slimy spores, and as they grow the spores may turn black, brown, or grey. Whereas, green mold growths can produce spores that begin as green or black and turn pink with maturity.
