Can My Dishwasher Kill Mold?

No, your dishwasher does not kill mold. For optimal cleaning performance and to prevent damage to dishes, water entering the dishwasher must be at least 120 degrees F and not more than 150 degrees F.  According to Michael Pugliese, author of The Homeowner’s Guide to Mold (available on Amazon), most mold spores thrive in temperatures up to 120 degrees Fahrenheit, with many species living to temperate well beyond boiling.

What about Mold in the Dishwasher?

It can be tempting to believe that every time your dishwasher runs through a cycle, it gets a cleaning itself. Unfortunately, this is not the case. While you likely view your dishwasher as a useful appliance that conveniently cleans your messy dishes and saves you time, what you might not know is that it can actually be a safe haven for mold and bacteria to live and grow in.

Now, you might be wondering… what about the high temperatures and detergents used in the dishwasher? Don’t those kill off unwanted microbes? Unfortunately, the answer is no. Mold can survive the entire dishwasher cycle – detergents, hot temperatures and all. In addition, most dish-washing detergents contain salt, which yeasts and black mold thrive on.

The modern household actually provides many ideal environments for mold and fungal growth, especially in moist, dark areas like the refrigerator and the dishwasher. The humidity and potential for leaking water in these areas create a perfect environment for unwanted mold and bacteria to live in.

What Causes Mold in the Dishwasher?

Microbes like mold (fungus) and bacteria only require a few basic elements to live and thrive: heat, moisture, organic material, and darkness. Your dishwasher checks all of these boxes, so it should not surprise you that having some sort of mold or fungus growing in your dishwasher is actually quite common.

Why is There Mold in the Dishwasher?

The leftover food particles in your dishwasher, in addition to the humid, dark, wet environment, provide an ideal location for these unwanted microbes to live in.

There are plenty of different types of molds, each with their own qualities and preferences. Some will grow around leftover food particles, other types prefer rubber parts of the dishwasher or within the drain seal.

Allowing mold buildup to persist inside your household dishwasher puts you and your family at risk for potential negative health effects. Exposure to mold may cause a variety of symptoms. Some people are especially sensitive to mold; in these cases, mold exposure might cause nasal stuffiness, throat or eye irritation, coughing, wheezing, or skin irritation. Certain people are allergic to mold, which could result in even more severe reactions.

Young children, the elderly, and people with compromised immune systems are at the highest risk for illnesses that are triggered by exposure to mold. Immune-compromised people and those with chronic lung illnesses can get serious infections in their lungs when they are repeatedly exposed to mold. Any individual that takes antibiotics is also at a higher risk as well as diabetics. If anyone in your household falls into any of these higher risk groups, it is that much more important that you take extra precautions in preventing mold growths from persisting in your household.

How to Clean Mold from a Dishwasher

Now that you know your dishwasher is likely harboring some unwanted guests, it is time to figure out what to do about it. To get a handle on mold in the dishwasher, you need to focus on doing three things: disinfecting, cleaning, and ventilating.

DO NOT use bleach. Bleach is often (incorrectly) touted as one of the most effective solutions for eliminating mold growth. However, it is not suitable for use in your dishwasher. It is caustic and might cause negative effects to both your health and the health of your dishwasher. In addition, chlorax kills only the surface parts of the mold, bleaching out the color to make it look like it is gone. This process leaves the hyphe (like roots) in the rubber or other materials, so that the mold often grows back with a vengeance.

Also, Bleach might damage the heating probes within the dishwasher, meaning it will be unable to effectively dry your dishes, leaving them covered in water droplets, and therefore creating a perfect humidity chamber for mold to continue to grow.

Instead, make use of baking soda and vinegar; these ingredients, when added together, create a foamy paste that is both safe for use inside your dishwasher and is more effective in killing off mold, bacteria, and other potentially harmful microbes. Vinegar kills up to 99% of bacteria and 82% of mold species.

Mix small amounts of baking soda into a cup of vinegar until the mixture forms a foamy paste. Using a dish scrubbing brush, scrub the dishwasher, paying close attention to the small cracks, crevices, and harder-to-reach areas inside of the dishwasher. You can also use a toothbrush to get into smaller areas more effectively.

Once you have finished cleaning out your dishwasher, you can put vinegar into a spray bottle and spray the inside or place a full cup of vinegar on the top rack of the dishwasher and run through a regular cycle. Once the cycle is done, ensure you open the dishwasher in order to allow the inside to dry fully.

Tips to Prevent Mold in the Dishwasher

Here are some further tips for preventing mold from growing in the dishwasher:

• Thoroughly clean your dishwasher at least once a month
• When cleaning, pay close attention to the rubber parts of the dishwasher, including the seal along the perimeter, as these are prime locations for mold growth
• Keep your dishwasher door slightly open when it is not in use to provide ventilation and keep the surfaces inside the dishwasher dry
• Control the humidity in your kitchen; if the humidity less than 60%, you are safe (an air conditioning unit or dehumidifier will help, in addition to ensuring your kitchen is properly ventilated with exhaust or fans)
• Most dishwashers share a drain with the kitchen sink, so if your sink has a garbage disposal, ensure that you run it and that it is cleared before turning on your dishwasher
• Remember, if there is mold in the dishwasher, the best thing you can do is address the problem right away; remove the mold and then put prevention methods into place to keep the dishwasher clean moving forward.

Sources

1. www.ultra-fresh.com/
2. www.emlab.com/resources/education/environmental-reporter/how-does-heat-affect-fungi-bipolaris-species/
3. www.sciencedirect.com/science/article/abs/pii/S2214799317301248