Shower curtain
Permanently damp, rarely dried and almost never washed — which is why it grows the thing people then try to bleach off it.
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What this is, what tends to go wrong with it, and what to do about it.
Made from
What tends to go wrong
The flat, powdery surface growth that appears on damp fabric, grout and shower curtains — and the carpet trade's procedure for it names no bleach at all.
Why it is difficult: Moisture control and recurrence, Porous and non-porous surfaces, Organic load
A hard, chalky calcium carbonate deposit left by hard water. Dissolved by acids, essentially untouched by detergents.
Why it is difficult: Water hardness, Crystallisation, Adhesion and cohesion
The organisms behind the marking. Around 1.5 million species, each with its own conditions — and killing them does not end the exposure they created.
Why it is difficult: Organic load, Moisture control and recurrence, Biofilm
- Dustvia its material
Mostly textile fibres and skin, held by static as much as by gravity — which is why a dry cloth on a plastic surface makes it worse.
Why it is difficult: Static and dust, Mechanical action and abrasion, Why different surfaces get different dirt, Surface roughness
- Perspirationvia its material
Sweat itself has almost no smell. What you can smell is bacteria eating it — and which bacteria depends on what the garment is made of.
Why it is difficult: Classifying a stain by its origin
- Soap scum· no established method
Not scale and not dirt: a metal soap formed when hard water meets true soap. It is the reason a shower screen films over in one house and not another.
Why it is difficult: Insoluble metal soaps, Water hardness, Evaporative deposition, Adhesion and cohesion, Why different surfaces get different dirt
A concentrated water-soluble dye with nothing else in it. Nothing has to be emulsified or dissolved — the only question is whether the surface has taken the colour up.
Why it is difficult: Capillary absorption, Dye migration and colour bleeding
A sticky, yellow-brown tar film deposited everywhere at once. It is the reason a room smells after everything visible has been cleaned.
Why it is difficult: Adsorption of odour molecules, Solubility and polarity
Coloured by turmeric in most prepared mustards, and curcumin is a pH indicator — which is why an alkaline cleaner turns a yellow mark red.
Why it is difficult: pH indicators in stains, Fat-soluble pigments, Photodegradation, Pigment retention
The commonest cleaning problem that is not dirt. The tackiness is the plastic's own additive arriving at the surface, which is why wiping it off works for a week.
Why it is difficult: Plasticizer migration, Damage versus soiling
Two stains in one bottle: an oily film, and a UV filter that forms a coloured complex with the iron in your water. The second one is why the mark comes out orange.
Why it is difficult: Chelation, Water hardness
The science behind this: Solvent crazing, Static and dust, Solvents and polymers, Plasticizer migration, How care labels work, Adsorption of odour molecules
In detail
A shower curtain collects two deposits and grows one organism, and all three come from the same cause. Soap scum forms where hard water meets soap on the plastic or fabric surface; limescale deposits where droplets evaporate in place; and mildew establishes in the folds at the bottom, where the material stays wet longest and dries slowest. The mould authorities' position applies directly: the moisture problem must be corrected or growth returns, and a treatment that removes the visible growth without changing the drying conditions buys weeks. The practical measures are unglamorous — let it dry fully after use and ventilate the room. On a plastic liner, replacement is cheap enough that repeated bleaching is rarely the better answer.
Related
- Shower curtain is made from Household plastics
- Shower curtain is made from Polyester
- Shower curtain is commonly affected by Mildew
- Shower curtain is commonly affected by Soap scum
- Shower curtain is commonly affected by Limescale
- Shower curtain is commonly affected by Mould fungi
Sources for this page
Sources
United States Environmental Protection Agency (EPA) · Government or regulator
Relied on for: That water problems are fixed and items dried completely and that porous materials which have been colonised may need to be discarded. (states this directly)
Spot Solver: spot and spill removal procedures
The Carpet and Rug Institute (CRI) · Trade or professional body
Relied on for: That the mildew entry names no bleach. (states this directly)