Pink Mold: What Is It and How to Get Rid of It

person scrubbing a bathroom floor

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Have you noticed that the grout or caulking in your bathroom is turning pink or the delicate shade of orange sherbet? Well, the good news is the cause isn't toxic mold. The bad news is that the cause is bacteria. Let's take a look at what's growing in your shower and how to remove it.

What Is "Pink Mold"?

When we see something growing in moist areas like our bathrooms, the immediate assumption is that it is mold. But when you see pink, light red, or light orange growth spreading across the grout in the shower, it is water-borne bacteria, Serratia marcescens. The bacterial colony, which grows and spreads in warm, moist environments, can appear to be fuzzy or slimy. The color range is affected by room temperatures.

An opportunistic bacteria, Serratia marcescens is usually transferred to surfaces through poor hygiene after handling body fluids (urine, feces, pus). The presence of the bacteria is harmful to those with compromised immune systems, babies, those with open wounds, and pets.

While small colonies seldom cause severe illness, if left to spread the bacteria can result in urinary tract and bladder infections, blood poisoning, endocarditis, pneumonia, meningitis, and bone infections through open sores.

pink mold in a petri dish

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How to Remove Pink Mold

What You'll Need

  • Baking soda
  • Dishwashing liquid or all-purpose cleaner
  • Chlorine bleach
  • Nylon-bristled scrub brush
  • Spray bottle
  • Small bowl
  • Rubber gloves
  • Protective eyewear
  • Mask (preferably N-95)
  • Washing machine
  • Laundry detergent
  • Squeegee
  • Towels
  1. Mix a Cleaning Solution

    In a small bowl, mix one-half cup of baking soda with one tablespoon of dishwashing liquid or an all-purpose cleaner. The paste will be runny. Depending on how much area you need to clean, you may need to make a double batch.

  2. Put on Protective Gear

    It is important to wear rubber gloves, protective eyewear, and a mask to protect yourself from exposure to the bacteria. If you have open sores, they should be covered, as well.

  3. Remove the Shower Curtain and Liner

    Since the bacteria can grow on plastic and fabric surfaces, it is a good idea to clean the shower curtain and liner even if you can't see any pink growth on the surfaces. Toss washable curtains and liners in the washing machine and wash in warm to hot water with your regular laundry detergent. Fabric curtains can be dried following the care label instructions but plastic liners should never be placed in an automatic dryer. Hang the liner from an outdoor clothesline or drying rack instead. Consider replacing plastic shower curtains and liners.

  4. Scrub Away the Bacteria

    Dip a nylon-bristled scrub brush in the baking soda solution and start scrubbing. Start at the highest point of the growth and work your way down the surfaces. The baking soda provides a gentle abrasive to help loosen the bacteria from the surfaces.

  5. Rinse the Area

    Rinse away the baking soda and bacteria with a hand-held shower spray or by dipping a towel in water to wipe down the walls and hard surfaces.

  6. Prepare the Disinfectant Solution

    Since bacteria can be difficult to kill, the area will need to be treated with a disinfectant solution to be sure the bacteria is dead. In a spray bottle, mix a 50:50 solution of warm water and chlorine bleach.

  7. Disinfect the Infested Area, Wait, and Scrub Again

    Spray the freshly cleaned area liberally with the bleach and water solution. Allow the solution to work for 10 to 15 minutes. This length of exposure should kill any lingering bacteria and remove any stains that may remain on the surfaces. Use a clean scrub brush to go over the surfaces one more time.

  8. Rinse and Dry the Surfaces

    Rinse the surfaces well to remove the bleach solution. Dry with a squeegee or towels to remove moisture and prevent streaks.

  9. Hang the Shower Curtain

    Hang the freshly washed and dried shower curtain and liner.

Tips to Prevent the Growth of Pink Mold

  • Encourage hand-washing, especially after using the bathroom, to prevent the transfer of Serratia marcescens bacteria to other surfaces.
  • Keep surfaces dry. Since Serratia marcescens needs moisture to thrive and spread, take the time to dry shower walls after each use. A squeegee can do the job in just seconds or use a towel.
  • Close and straighten shower curtains so they will dry more quickly and wash the curtains and liners at least monthly.
  • Clean away soap scum at least weekly. Soap scum contains body soil that serves as food for mold and bacterial growth.
  • Wipe away spills and drops of liquid soap, shampoo, and conditioner from the walls and floor of the shower or tub after each use.
  • Reduce the humidity level in your home by using exhaust fans, dehumidifiers, and repairing leaky plumbing.