Pink Mold: The Uninvited Guest in Your Sink

At first glance, you might mistake it for a splash of paint or a trick of the light, but that light pink stain in your sink or shower is a living organism.

Pink mold is a misleading term; it's actually a type of bacteria known as Serratia marcescens. This bacteria is found naturally in soil, food and animals. It thrives in moist environments and doesn't need much to survive.

Aside from your sink, this pink bacteria can make a home on various surfaces, especially in bathrooms. You might find pink mold on shower curtains, shower walls and even in the soap scum that builds up over time.

It loves to lurk in damp areas, so your shower is like a five-star hotel for these uninvited guests.

For most people, pink mold is more of a nuisance than a health threat. (It's nowhere near as gnarly as black mold.) However, for those with compromised immune systems, open wounds or bladder infections, pink mold can pose health risks and has been linked to urinary tract infections and pneumonia.

The bacteria can enter the body through open wounds or be inhaled, leading to infections. It's important to tackle pink mold as soon as you spot it on your shower curtain to minimize these risks.

There are a few reasons why pink mold might be showing up in your sink. One possible cause is too much iron in your water, particularly if you're using well water. This iron starts as a reddish stain that fades to pink over time. A water filtration system can usually solve this problem.

Another common cause is airborne Serratia marcescens bacteria. This bacteria can enter through open bathroom windows or be stirred up during construction or remodeling.

Soap scum is like a buffet for pink mold. When you use your sink or shower, you leave behind residues from liquid soap, bath soap and even shampoo. This residue, combined with the warm water and damp environment, creates the perfect breeding ground for pink mold growth.

Preventing pink mold involves keeping your bathroom well-ventilated and dry. Use an exhaust fan during and after showers to remove excess moisture. Regularly wipe down surfaces to prevent water pooling.

Keep shower doors and curtains open to air out, and consider using a squeegee to remove water from shower walls.

When it comes to getting rid of pink mold, regular cleaning is key. For a DIY cleaning solution, mix white vinegar and hot water in a spray bottle. Apply it to the affected area and let it sit for a few minutes before scrubbing with a soft bristle brush or nylon bristle brush.

For tougher stains, a mixture of baking soda and liquid dish soap can be effective. Remember to wear rubber gloves to protect your hands.

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This article was updated in conjunction with AI technology, then fact-checked and edited by a HowStuffWorks editor.