No, dehumidifier water is not safe to drink
Water collected from a dehumidifier contains bacteria, mold spores, and minerals that make it unsafe for drinking or cooking. The water sits in a tank or bucket where microorganisms grow, and the coils that pull moisture from the air shed particles into the collected water. Even if the tank looks clean, pathogens invisible to the eye can cause stomach illness.
The minerals in dehumidifier water come from the air itself — dust, pollen, and other particles that condense along with the moisture. These are not harmful in small amounts, but the bacterial load is the real problem. A dehumidifier tank is a warm, wet environment where bacteria and mold thrive, and most home dehumidifiers have no filtration system to stop this growth.
Key Takeaways
- Dehumidifier water contains bacteria and mold spores that cause stomach illness if swallowed.
- The collection tank creates ideal conditions for microbial growth because it stays warm and wet.
- Dehumidifier water is safe for watering plants, cleaning floors, and filling toilet tanks.
- Boiling dehumidifier water does not make it safe to drink because it does not remove all contaminants.
- If you want to reuse dehumidifier water, use it only for non-potable purposes and empty the tank regularly.
What grows in a dehumidifier tank
The collection tank in a dehumidifier is a breeding ground for bacteria and mold because the conditions are perfect: moisture, warmth, and organic matter from dust and skin cells in the air. Within days of use, bacterial colonies form on the tank walls and in the water itself. Mold can grow even faster, especially if the tank sits for more than a few days without being emptied.
The coils inside the dehumidifier also shed particles — bits of metal, plastic, and mineral deposits — that fall into the water. These particles are not toxic on their own, but they carry bacteria on their surface. Even if you filter out the visible particles, the microorganisms remain.
Some dehumidifiers have a drain hose that runs to a floor drain or bucket, which reduces standing water but does not eliminate the problem. The hose itself can harbor bacteria and mold, especially if it sits unused between seasons.
Why boiling does not make it safe
Boiling kills most bacteria and viruses, but it does not remove all contaminants in dehumidifier water. Minerals, dust particles, and some heat-resistant bacterial spores survive boiling. Boiling also does not remove mold toxins that may already be present in the water.
If you want to use dehumidifier water for drinking or cooking, you would need to boil it and then filter it through a fine filter (0.1 micron or smaller) to remove spores and particles. This is not practical for most people, and even then, the water quality would be lower than tap water. It is simpler and safer to use tap water for drinking and cooking.
Safe ways to reuse dehumidifier water
Dehumidifier water is safe for many household tasks that do not involve drinking or cooking. You can use it to water indoor plants, outdoor gardens, and lawns. Plants do not absorb bacteria the way humans do, and the minerals in the water can actually benefit soil.
You can also use dehumidifier water to clean floors, wash windows, and fill toilet tanks. For cleaning, the bacteria and minerals are not a concern because the water is not ingested. Toilet tanks are designed to handle water that is not potable, and the chlorine in most municipal water systems is not necessary for this purpose.
If you want to reuse dehumidifier water, empty the tank at least once a week to prevent mold and bacterial buildup. If you notice a smell or visible growth in the tank, clean it with a mixture of equal parts white vinegar and water, then rinse thoroughly before refilling.
How to reduce contamination in the tank
You cannot eliminate contamination entirely, but you can slow its growth. Empty the tank regularly — ideally every three to five days during heavy use. The longer water sits, the more bacteria multiply.
Keep the tank and coils clean by wiping the inside of the tank with a dry cloth before refilling. If you see mold or slime, clean it with vinegar and water. Some dehumidifiers have removable tanks that are easier to clean than built-in reservoirs.
If your dehumidifier has a drain hose option, use it instead of collecting water in a tank. Running water to a floor drain or outdoor area prevents standing water from accumulating. Make sure the hose is clean and not kinked, which can trap water inside.
What happens if you accidentally drink dehumidifier water
Drinking a small amount of dehumidifier water by accident is unlikely to cause serious illness, especially if your immune system is healthy. However, larger amounts or repeated exposure can cause nausea, diarrhea, and stomach cramps. Children, elderly people, and those with weakened immune systems are at higher risk for infection.
If someone drinks dehumidifier water and develops symptoms like stomach pain, vomiting, or diarrhea within a few hours, contact a doctor or poison control. Have the dehumidifier model number available so you can describe what the water may have been exposed to. In most cases, the illness resolves on its own with rest and hydration, but medical attention may be needed if symptoms are severe.
Dehumidifier water versus other collected water
Rainwater collected in a barrel is also not safe to drink without treatment, but for different reasons. Rainwater picks up bacteria and chemicals from roofs and gutters. Dehumidifier water is contaminated by the machine itself and the indoor air it pulls from.
Distilled water made by a water distiller is safe to drink because the distillation process removes bacteria, minerals, and other contaminants. A dehumidifier is not a distiller — it straightforward condenses moisture without purifying it. The two machines look similar but work very differently.
Frequently Asked Questions
Can I drink dehumidifier water if I boil it and filter it?
Boiling and filtering reduces some contaminants, but does not remove all bacteria, spores, and minerals. To make dehumidifier water truly safe would require multiple filtration steps and testing, which is not practical. Tap water is safer and costs less.
Is dehumidifier water safe for pets to drink?
No. Pets have the same risk of bacterial infection as humans. Do not leave dehumidifier water where pets can access it. If a pet drinks it, watch for signs of stomach upset and contact a veterinarian if symptoms develop.
Can I use dehumidifier water in a humidifier?
You can, but it is not recommended. The minerals and bacteria in dehumidifier water can clog the humidifier and spread contaminants into the air. Distilled water is the better choice for humidifiers because it is free of minerals and microorganisms.
Does the type of dehumidifier matter for water safety?
No. Both refrigerant and desiccant dehumidifiers produce water that is unsafe to drink. The collection method and tank design vary, but all dehumidifiers create conditions where bacteria and mold grow in the collected water.
How long can dehumidifier water sit before it becomes unsafe?
Bacteria begin growing within hours of collection. After 24 hours, the bacterial load is significant enough to cause illness if ingested. Empty the tank regularly and do not store dehumidifier water for more than a few days, even in a sealed container.