What is Soap Scum?

Mary McMahon
Mary McMahon

Soap scum or limescale is a filmy layer that forms around showers, sinks, tubs, and other areas where soap and water are often present together. It is caused by the minerals that are naturally present in water. When these minerals combine with soap, they create a sticky mixture that adheres to surrounding surfaces, slowly creating a scaly buildup that may also include body oils, dead skin, hair, and dirt. For many people, soap scum is a regular cleaning bugbear, especially if they live in areas with hard water.

A bar of soap.
A bar of soap.

Regular soap scum is white to gray in color, but it often acts as an ideal substrate for algae and molds, and it may develop a rainbow of colors along with some undesirable odors. When limescale is allowed to build up to this point, it can also become very difficult to remove. Only heavy scrubbing and a strong cleaner will be able to penetrate the layers.

Soap and water.
Soap and water.

Most people are less interested in knowing what soap scum is and more interested in knowing how to get rid of it. The best way to deal with it is to clean regularly, preventing the buildup from becoming firmly adhered. Wiping down tubs, showers, sinks, and tile at least once a week can often keep soap scum to a minimum, especially if ammonia or vinegar is added to the sponge or cloth used for wiping, as these substances will cut through the layers. Detergent can also remove it. Wiping down a tub after using bath oils is also highly recommended.

A baking soda paste can be used to remove soap scum.
A baking soda paste can be used to remove soap scum.

Some people use wax and other products designed to increase water resistance to reduce soap scum by preventing the deposition of water on the walls of showers and tubs. This can be effective in some cases, but the wax can also become very messy, and it needs to be routinely stripped and reapplied.

For more heavy-duty cleaning, a commercial degreaser is often very effective against soap scum. People can also use specially formulated cleaning products or lemon juice, vinegar, or ammonia. A paste of baking soda and water can also work, with the baking soda acting as an abrasive to lift away the layers. When using heavy cleaners, people should leave a window open and wear gloves so that the cleaners do not irritate the lungs or hands.

Using vinegar with a sponge once a week is a good way to prevent soap scum.
Using vinegar with a sponge once a week is a good way to prevent soap scum.
Mary McMahon
Mary McMahon

Ever since she began contributing to the site several years ago, Mary has embraced the exciting challenge of being a wiseGEEK researcher and writer. Mary has a liberal arts degree from Goddard College and spends her free time reading, cooking, and exploring the great outdoors.

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Discussion Comments


Plus1 for Chemicalbill. I don't understand why people want to make their own concoction. There are companies who have dedicated their careers to getting rid of soap scum. Soap scum is a very difficult mineral to get rid of because it's insoluble in water. After testing a bunch of different cleaners and how well they get rid of soap scum, BioWorx did win.


Try a gel made of 1 part Original Dawn and 1 part white vinegar. Spray on, let sit for 20 minutes and wipe or rinse off. Works like magic! Good in the kitchen too.


There is new technology and understanding of soap scum. Soap scum is calcium stearate and magnesium stearate. Try using BioWorx "green" soap scum cleaner. They have discovered how to remove soap scum with a corn based surfactant. They show interesting laboratory proof they dissolve soap scum while other cleaners can't. Showers also have what is called sebum which vinegar and most other homemade products can't clean. Sebum is the waxy oil our bodies secrete. A good shower cleaner must remove soap scum, scale and sebum to be effective.


Of all the articles on how to remove soap scum that I've read, this is the only one that mentioned using industrial degreaser. That sounds like a great idea -- I am definitely going to try it. Yay, wisegeek, for thinking outside the box!


I've found that a good way to keep soap scum from building up in your bathroom is to spray the shower and bathtub down with a descaler or soap scum preventer right after you shower everyday.

Then come back around five minutes later and rinse it out -- you should be free of soap scum from shower doors to shower heads!


Soap scum has officially become the bane of my existence after moving into my new apartment. Bathroom soap scum, dishwasher soap scum, shower and bathtub soap scum, I've got it all.

Can anybody tell me some good, quick ways to clean soap scum that will not be budged? Is there some nuclear level soap scum cleaner out there that I can get? I'm getting desperate in my soap scum removal efforts!

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