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Black Mold in Sink Drain: How to Get Rid of Them?

Black mold can begin to form and fester in your bathroom and kitchen gave the presence of moisture and humidity. However, black mold in sink drain can be a new level of headache.

Whenever you see signs of black mold in the sink drain, you’d want to immediately get rid of it!

What causes black mold in the kitchen sink drain or bathroom sink drain?

The primary reasons for the formation and infestation of black mold in kitchen and bathroom sinks is the presence of too much moisture and humidity. Due to leaky drains, mold spores can come in contact with moisture. Food remains from washing hands and dishes stuck in the sink can also source mold.

Black mold in your bathroom or kitchen sink is an issue you should look out for. To keep your sinks mold free, you would first have to know and address the reasons that cause a mold infestation in the sink. Here are possible causes of black mold formation in your sink:

Moisture from leaky drain:

One of the most common reasons that cause a possible black mold in sink drain is a leaky drain. As you know, mold cannot grow, or thrive in a place where there is no moisture.

Whenever there is a leak in the drain, you can expect an abundance of moisture around that area since water is leaking constantly. Mold spores, being living organisms, fester on that moisture to gradually grow more.

Food remains in the kitchen sink:

In the kitchen, you are constantly cooking food, washing dirty dishes, and washing your fruits and vegetable.

With food being around all the time, kitchen sink drains are no stranger to food remains that need to be cleaned regularly.

If not cleaned, these food particles can be a major source of mold growth, joining hands with other factors. On contact with water, these food particles can get stuck in the sink drain and breed mold when mold spores from the air land on them.


Whether it is the bathroom or kitchen, humidity is a permanent resident in both these places. One of the factors that allow mold to grow and survive is proper heat or humidity.

Mold spores are microscopic organisms in the air that comes in contact with moisture and heat to become mold. In the kitchen, the heat from the stoves or microwaves produces enough humidity.

In your bathroom, when you use hot water showers or wash your hands with warm water, mold spores absorb the required heat.

Signs of black mold in the sink drain:

Whether it is your bathroom sink or kitchen sink, there would always be signs indicating that black mold has formed in the sink drain.

It’s a wise idea to be on the lookout for these signs so that you can prevent the mold from spreading or increasing. Here are a few signs of black mold in the sink drain:

A stale and musty smell:

One of the first and most obvious signs that notify a possible mold infestation is the distinct smell of mold in sinks. You would be able to detect a somewhat stale and rather musty smell.

The color of the mold:

Black mold is black and cannot escape your eyes if you are to check the sink or the drain. Sometimes the mold crawls up to the top of the sink drains and becomes visible.

Allergic symptoms:

Mold gives your certain symptoms of allergy when around and more severe ones if you are sensitive to it. If you notice yourself sneezing or having a runny nose after going near the sink, you might be having mold in the sink.

Damaged look:

If there is mold in the sink, you would be able to tell by a drain that looks faded and discolored. The walls around might also be crumbly, the environment would be damp.

How to get rid of black mold in the sink drain?

There are several ways in which you can get rid of black mold in the sink drain. One way is to disassemble the tailpiece pipe or stopper strainer to scrub off any mold. You can also use natural cleansers like a combination of baking soda, vinegar, salt, and hot water to pour down the drain.

There can be multiple ways to get rid of the black mold from the drain lines. Let’s get to know them.

Scrub it:

If you notice black mold on your drain sink or around it, you would need to scrub it off clean. To scrub off mold completely, you would need to take off the stopper and strainer. Disassembling the tailpiece can also be another way to clean the drain sink.

Before taking off the strainer or tailpiece, make sure to turn the valve off before you start. If you are doing the latter, make sure you get yourself pliers or wrenches.

You would need to unscrew the nuts on the pipe that links to the p trap. After unscrewing, you can remove the pipe, hence the tailpiece.

You would need to scrub the mold off using a brush. Before it all, you would need to remember that it is important to wear protective gear at all times.

A mask, gloves, and goggles will help you get rid of any post-work allergic symptoms. You would also need some dish soap to scrub the mold away.

Making it wet before cleaning it and waiting out a few seconds would soften the mold. Scrub out thoroughly and rinse the space with clean water afterward.

Go for natural cleaners:

Without doing much of the mechanical work of disassembling the pipes, you can also get rid of black mold from the sink drain effectively and safely. Instead of using chemical cleaners, opt for natural cleaners to pour down the sink drain.

One of the best mixtures of natural cleaners is baking soda and vinegar. You need to pour half cups of each down the drain for them to react accordingly.

Pour the baking soda followed by vinegar. You would then need to wait out for about 10 to 15 minutes until you notice the reaction forming bubbles on the top of the sink.

To do this, you would need to add hot water mixed with half a cup of salt. You can also use boiling water with salt if the pipes are metal. The saltwater will get rid of the mold infestation but it will also help to rinse out the baking soda and vinegar solution.

Is black mold in the sink drain dangerous?

Black mold in the sink drain can cause health issues when inhaled or ingested. Hence it can be considered to be somewhat dangerous when found in the sink drain.

Since the sink drain is a space where we wash our hands and face, there could be a chance that mold comes in contact with our hands and face.

In that case, the mold may cause more serious allergic reactions, especially in people who are more sensitive to mold organisms.

Symptoms of a black mold allergy could be mild to severe, including sneezing, runny nose, coughing, and typical cold or flu symptoms. However, in many, it could even result in skin rashes and itchy eyes, nose, and throat.

If you or anyone in your house has respiratory issues like asthma, black mold in the sink drain can be dangerous. This is because, being in close contact with the sink drain, and hence black mold can trigger asthma.

If the black mold in the sink drain is allowed to fester for a long time and if someone inhales the organisms, it can contribute to chronic allergic problems, brain fog or fatigue, and even mold in the lungs in the long term.

How to prevent black mold in the sink drain from coming back?

To prevent the formation of black mold in the sink drain, you would need to take a few steps:

Clean regularly:

Cleaning the sink drain regularly can help prevent mold formation in the sink drain.

From time to time, preferably once in 10 to 15 days, you can use the baking soda and vinegar method to remove the mold. However, you may want to use quarter cups of each ingredient in case of regular cleaning.

Make a mixture:

Similarly, make a mixture of water, hydrogen peroxide, vinegar, and borax to pour down the sink drain. Wait a few minutes before rinsing out with clean water.

Keep ventilated:

Make sure to keep the area well ventilated, by keeping windows open and exhausts on to dispose of the extra humidity and moisture in the room.

Final thoughts

If you see black mold in your drain sink, it could be due to a leaky drain.  Too much heat and humidity, stuck up food, and gunk, can also cause mold to form. Scrubbing the mold off and using a natural cleanser can get rid of the mold. Keep the sink clean and moisture free to prevent mold.