You wash your towels regularly, use quality detergent, and still—mysterious orange or pink stains keep appearing, clinging stubbornly no matter how many times you rewash them. They’re not rust, not mildew, and definitely not from your skincare products. So what gives?
The culprit? Serratia marcescens—a naturally occurring airborne bacteria that thrives in damp, humid environments like bathrooms. And before you panic: it’s usually harmless for healthy people, but it is unsightly, persistent, and a sign your bath linens need a little extra care.
The good news? You can stop these stains for good—without bleach, harsh chemicals, or replacing your entire linen closet. Let’s uncover the science behind those orange spots and how to keep your towels fresh, fluffy, and stain-free.
What Causes Those Orange/Pink Stains?
Despite the rust-like appearance, these stains are biological, not mineral-based. They’re caused by Serratia marcescens, a pinkish-red bacterium commonly found in:
Soil
Dust
Bathrooms (especially on tiles, grout, and shower curtains)
Humid air
This bacteria feeds on fats, phosphates, and minerals found in:
Soap scum
Shampoo residues
Body oils
Fabric softener buildup
When your damp towels sit bunched up in a hamper or stay wet for hours, Serratia multiplies—leaving behind that telltale orange-pink biofilm that regular washing won’t remove.
