Pink Shower Slime
Not mouldSerratia marcescens · also called pink mould, orange bathroom slime
This is not mould. It is included because it is mistaken for mould constantly, and recognising it saves an unnecessary remediation.
This is not mould. It is a bacterium that feeds on the fatty residues from soap and shampoo, which is why it appears in showers and around drains rather than on walls. It is genuinely harmless to healthy people on intact skin, though it can cause infections through open wounds or in medical settings.
Quick facts
- Appearance
- A pink, salmon or orange slimy film in shower corners, around drains, in toilet bowls and on shower curtains. Slick rather than fuzzy, and it smears rather than brushing off as powder.
- Moisture
- Needs surfaces that stay genuinely wet
- Smell
- None distinctive.
- Colours
- pink, orange
- Texture
- slimy
- Surfaces
- grout, drywall
How to recognise it
- Slimy and smearing rather than fuzzy or powdery.
- Pink to orange, always in wet zones with soap residue.
- Returns within days of cleaning if soap film is not removed.
- Bacteria, not fungus — so mould-specific products are beside the point.
What it tells you about the building
Soap residue plus constant moisture. Rinsing surfaces after use and drying them is more effective than any cleaner.
What it gets confused with
One observation settles each of these.
Mildew is dark and powdery; Serratia is pink and slimy.
Where it turns up
The species matters less than you think
- Public health guidance is to remove all indoor mould regardless of type. The CDC and EPA do not recommend routine species testing for ordinary households, because the response does not change: find the water, stop it, remove the growth.
- “Toxic black mould” is a marketing phrase, not a category. Stachybotrys is real and does need soaked material to grow, so finding it tells you something useful about your building. But the health effects that are well established — allergy, asthma aggravation, irritation — are not specific to it.
- Mould without water does not persist. Cleaning growth while leaving the moisture source is why it comes back. The leak, the condensation or the ventilation is the actual problem.
Call a professional for areas larger than about 10 square feet, for anything in HVAC ductwork, after sewage or flood water, or if anyone in the household is immunocompromised or has a lung condition.