What is pink mold? When it comes to maintaining a clean and healthy bathroom, pink mold is a common yet often misunderstood issue. What is important to know is that while some may consider the pink slimy material as maybe being mold, it is not.

What you see is a common bacterium known for producing pink or reddish biofilm, and requires effective sanitation and preventive measures. So why does it appear in our bathrooms? More importantly, how can you eliminate the pink biofilm (Serratia marcescens) and prevent it from returning? This blog will provide a comprehensive guide to understanding this pink biofilm, its causes, and the most effective ways to eliminate it from your bathroom.

Bacteria commonly develops on wet bathroom tiles and the surrounding grout.

What is the Pink Biofilm called Serratia marcescens?

The pink biofilm, commonly found in bathrooms, as mentioned earlier is not actually mold but a type of bacteria called Serratia marcescens. This bacterium thrives in damp, humid environments, making bathrooms the perfect breeding ground. This pink biofilm often appears as slimy pink or orange patches and can be found on shower curtains, tile grout, sinks, and other moist areas.

What Causes Serratia marcescens?

Understanding what causes the pink biofilm is essential for effective prevention and removal. The primary factors contributing to this pink or red coloration which comes from a pigment called prodigiosin growth include:

Regularly cleaning and maintaining your bathroom can significantly reduce the risk of a pink biofilm infestation.

How to Get Rid of Serratia marcescens (Pink Biofilm)

If you’ve discovered the pink biofilm in your bathroom, removing it and preventing its return immediately is crucial. Here’s a step-by-step guide on how to get rid of the biofilm layer:

  1. Safety First: Wear protective gloves, a mask, and eyewear to avoid direct contact with the pinkish slimy biolayer and its spores.
  2. Initial Cleaning: Use a non-abrasive scrub brush and a mixture of water and dish soap to clean the affected areas. This will help remove the bulk of the biolayer film.
  3. Disinfect: Apply a disinfectant such as bleach or a commercial bathroom cleaner designed to kill bacteria. Ensure the room is well-ventilated when using strong chemicals. (Use a bleach solution—1 cup of bleach in 1 gallon of water—to scrub affected areas).
  4. Why is bleach effective for this biofilm layer? Bleach typically contains sodium hypochlorite(NaClO), a strong oxidizing agent. Odium hypochlorite breaks down microbial cell walls and membranes, causing the contents to leak out, which kills the bacteria, however, bleach does not kill mold spores, and that is why mold usually returns within a week or two. Bleach oxidizes essential proteins and enzymes in the bacteria, disrupting their structure, and rendering them nonfunctional, while damaging DNA and RNA, preventing replication of Serratia marcescens. Serratia marcescens often forms a slimy biofilm that protects it from mild cleaning agents rendering them ineffective. 
  5. Alternate Suggested Solution for Serratia marcescens
    1. Vinegar
      • Use to clean and loosen biofilms or mineral deposits before applying a stronger disinfectant.
      • Allow it to sit for 10-15 minutes, then scrub and rinse.
    2. Hydrogen Peroxide
      • Use as a final disinfectant after cleaning the surface with vinegar or soap.
      • Spray 3% hydrogen peroxide directly on the area, let it sit for at least 10 minutes, and then wipe clean. (DO NOT MIX THE TWO PRODUCTS TOGETHER)
  6. Rinse and Dry: Thoroughly rinse the cleaned surfaces with water and dry them completely to prevent moisture buildup.
  7. Seal Grout and Caulk: If the pink biofilm has penetrated the grout or caulking, consider resealing these areas to create a barrier against moisture.

Mold often grows near the floor.

Preventing the Pink Biofilm

Once you’ve successfully removed pink biofilm from your bathroom, it’s essential to take preventive measures to keep it from returning. Here are some effective strategies:

Cost-Effective Solutions for Pink Serratia marcescens

Dealing with the pink slimy biofilm doesn’t have to be expensive. Here are some cost-effective solutions and tips:

Health Risks Associated with Pink Serratia marcescens

While Serratia marcescens may seem harmless, it can pose significant health risks, particularly for individuals with weakened immune systems. Prolonged exposure to Serratia marcescens can lead to various health issues, including:

Given these potential health risks, it’s crucial to address pink biofilm issues immediately and take preventive measures to avoid recurrence.

As seen on this milk curd, pink bacterium can thrive with the right conditions(even inside your refrigerator).

PuroClean Can Provide Professional Help for Persistent Mold or Bacterium such as Serratia marcescens Problems 

While DIY treatment methods can be adequate for small areas of Serratia marcescens growth, extensive infestations or recurrent mold problems may require professional intervention. Professional mold remediation services can ensure thorough cleaning and long-term prevention, protecting your home and health.

At PuroClean, we specialize in effectively remediating, restoring, and cleaning properties to ensure a safe and healthy environment for everyone. If you’re facing challenges with Serratia marcescens, bacteria from sewage, or other water-related issues, our certified professionals are here to help. Contact your local PuroClean franchise for a thorough assessment and customized plan of action. For expert assistance, visit our office locator or call us at (800) 775-7876. Trust PuroClean to protect your home or business and provide peace of mind with our reliable restoration solutions.

Refer to The Center for Disease Control and Prevention’s (CDC) Mold Guide for further information on mold and its health effects. Understanding what causes pink biofilm and how to get rid of it can help you maintain a healthier home. By following the tips and strategies outlined in this blog, you can effectively manage and prevent Serratia marcescens or other harmful bacteria or mold from infesting your bathroom. For more expert advice and assistance, contact PuroClean today.