Soap
The original surfactant, and chemically not the same thing as detergent. In hard water it precipitates, which is where the film on a shower screen comes from.
In detail
Soap and detergent are used as synonyms in ordinary speech and they are different substances with different failure modes, which is a distinction worth holding because one of them explains a problem the other cannot. Soap is a salt of a fatty acid, made by treating a fat or oil with an alkali. It works as any surfactant does, with a fat-loving tail and a water-loving head. What makes it different is what happens in hard water: the calcium and magnesium dissolved in the water displace the sodium and produce calcium and magnesium salts of those same fatty acids, which are not soluble. They come out of solution as a curd. That curd is soap scum, and it is why a shower screen in a hard-water area films over while the same soap in a soft-water area does not. Synthetic detergents were developed precisely to avoid this — their heads do not precipitate with hardness ions — which is why body wash tends to leave less film than a bar. The trade rule that follows is the useful one: soap film is a metal soap rather than a mineral scale, so it responds to something that will attack a fatty deposit as well as to something acidic.
Properties
- Chemical name
- Sodium salts of fatty acids
- pH
- Alkaline
What works
Soap is safe on, in specific conditions, Extractor grease filter
Safe only in specific conditions
This is only appropriate within specific limits, and nothing is established outside them.
Only within these limits:
- Mild soap and water
- Monthly, or when the filter status indicator asks
- Refit end-first opposite the tab area, then swing the other end up
The manufacturer's own interval and its own method. Nothing stronger is given.
Precautions
- Check the manufacturer's instructions
- Rinse thoroughly afterwards
Evidence
Supported
Sources
Cleaning the Filters (Grease and Charcoal) — Over-the-Range Microwave
Whirlpool Corporation · Manufacturer documentation
Relied on for: That the recommended method is mild soap and water and the interval is monthly or as prompted by the filter status indicator. (states this directly)
Soap is safe on, in specific conditions, Vitreous enamel
Safe only in specific conditions
This is only appropriate within specific limits, and nothing is established outside them.
Only within these limits:
- Soft cloth or sponge
- Surface cool
- Acidic food spills such as vinegar and tomato cleaned as soon as the appliance is cool rather than left
Porcelain enamel is acid-RESISTANT rather than acid-proof, which is why the timing instruction accompanies the permission.
Precautions
- Do not apply to a hot surface
Evidence
Supported
Sources
Whirlpool Corporation · Manufacturer documentation
Relied on for: That soap, water and a soft cloth or sponge is the primary method for a porcelain surface, and that acidic food spills should be cleaned as soon as the appliance is cool. (states this directly)
Soap is safe on, in specific conditions, Finished wood flooring
Safe only in specific conditions
This is only appropriate within specific limits, and nothing is established outside them.
Only within these limits:
- A WEAK solution of a mild soap in warm water, cloth wrung out well
- Second pass only, for stubborn dirt the solvent wipe did not lift
- Follow with a wipe using a cloth dampened in clear water, then dry completely
- Water very sparingly on veneered or inlaid work — one small area at a time, dried before moving on
Soap is permitted here and detergent is prohibited in the same paragraph. The source means the chemical class, and excludes a named dishwashing liquid to make that clear.
Precautions
- Test on an inconspicuous area first
- Rinse thoroughly afterwards
Evidence
Supported
Sources
Conserve O Gram 7/1: Cleaning Wood Furniture
National Park Service, US Department of the Interior, 1993 · Government or regulator
Relied on for: That a weak solution of a mild soap and warm water on a well-wrung cloth is directed for stubborn dirt, followed by a wipe with clear water and complete drying, and that water is used very sparingly on veneered or inlaid furniture. (states this directly)
Soap is safe on, in specific conditions, uPVC
Safe only in specific conditions
This is only appropriate within specific limits, and nothing is established outside them.
Only within these limits:
- Soapy water, as often as the location requires — more in industrially polluted or coastal areas
- Gaskets cleaned periodically as well as the profile
- ON NO ACCOUNT solvent-based cleaners
- Woodgrain foil finishes: ask the supplier which products are suitable
Hardware is a different answer entirely: handles, hinges and cylinders carry coatings and are cleaned with a DRY soft duster with no water at all.
Precautions
- Check the manufacturer's instructions
Evidence
Supported
Sources
PVC-U Window & Door Systems: Handling, Installation, Maintenance and Care Guide
The VEKA UK Group (VEKA and Halo profile systems), 2014 · Manufacturer documentation
Relied on for: That routine care is occasional cleaning with soapy water covering the profile and the gaskets, that solvent-based cleaners must on no account be used, that woodgrain foils are referred to the supplier, and that hardware is cleaned with a dry soft duster and no water. (states this directly)
Soap is safe on, in specific conditions, Painted walls
Safe only in specific conditions
This is only appropriate within specific limits, and nothing is established outside them.
Only within these limits:
- WAIT AT LEAST TWO WEEKS AFTER PAINTING before using any water or cleaner on the wall
- Dust first with a vacuum dust brush and then a tack cloth, whatever the paint type or sheen
- Mild soapy water on a soft cloth or sponge, thoroughly wrung out, gentle pressure in a circular motion
- Rinse with a clean damp cloth to remove leftover cleaner
Too much water can ruin the paint finish, which is why the wringing instruction is explicit. The manufacturer also gives the pass condition for the test patch: the paint still looks bright and no water marks remain after drying.
Precautions
- Test on an inconspicuous area first
- Rinse thoroughly afterwards
Evidence
Supported
Sources
How to Clean Newly Painted Walls
The Sherwin-Williams Company · Manufacturer documentation
Relied on for: That at least two weeks should pass after painting before using water or cleaner, that dusting comes first, that general washing is a soft cloth or sponge with mild soapy water applied with gentle pressure in a circular motion then rinsed, and that too much water can ruin the paint finish. (states this directly)
Soap is safe on, in specific conditions, Powder-coated aluminium
Safe only in specific conditions
This is only appropriate within specific limits, and nothing is established outside them.
Only within these limits:
- Mild dish soap, or a fifty-fifty water and vinegar solution
- No abrasive cleaners and no solvents
- Blot dry with a dabbing action rather than rubbing
The one finish in this manufacturer's document where vinegar is affirmatively permitted. Allowing water to evaporate on a metal finish forms deposits, which is why the drying instruction is a technique rather than a step.
Precautions
- Test on an inconspicuous area first
Evidence
Supported
Sources
KALLISTA (Kohler Co.) · Manufacturer documentation
Relied on for: That matte black and other powder coats may be cleaned with mild dish soap or a fifty-fifty water and vinegar solution, that abrasive cleaners and solvents are excluded across finishes, and that allowing water to evaporate on metal forms deposits so the surface should be blotted dry with a dabbing action. (states this directly)
Soap is safe on, in specific conditions, Stainless steel
Safe only in specific conditions
This is only appropriate within specific limits, and nothing is established outside them.
Only within these limits:
- Soap, detergent or a dilute one per cent ammonia solution in warm clean water
- Rinse and dry
- Wash after food preparation — salt, and concentrated salt and vinegar mixtures, may pit the steel over time
- No chloride solutions
The trade body rejects the idea that stainless steel is maintenance-free: it stains and discolours from surface deposits, and its corrosion resistance depends on the surface being kept clean.
Precautions
- Rinse thoroughly afterwards
Evidence
Supported
Sources
Care and Maintenance of Stainless Steel
British Stainless Steel Association, Stainless Steel Advisory Service, 2001 · Trade or professional body
Relied on for: That routine cleaning is soap, detergent or dilute one per cent ammonia solution in warm clean water, rinsed and dried, and that corrosion resistance depends on keeping the surface clean. (states this directly)
Soap is safe on, in specific conditions, Control knob
Safe only in specific conditions
This is only appropriate within specific limits, and nothing is established outside them.
Only within these limits:
- Soap and water on a soft cloth or sponge
- Wipe, never soak or immerse
- Nothing abrasive, and no oven cleaner
Precautions
- Check the manufacturer's instructions
- Disconnect from the power supply first
Evidence
Supported
Sources
Cleaning and Maintenance of Range
Whirlpool Corporation · Manufacturer documentation
Relied on for: That control knobs are cleaned with soap, water and a soft cloth or sponge, and that they must not be soaked or cleaned with steel wool, abrasive cleaners or oven cleaner. (states this directly)
Soap is safe on, in specific conditions, Oven control panel
Safe only in specific conditions
This is only appropriate within specific limits, and nothing is established outside them.
Only within these limits:
- Soap, water and a soft cloth or sponge first
- Then, if needed, glass cleaner, mild liquid detergent, all-purpose cleaner or a nonabrasive pad
- Rinse with clean water and dry with a soft lint-free cloth
Precautions
- Check the manufacturer's instructions
- Disconnect from the power supply first
Evidence
Supported
Sources
Cleaning and Maintenance of Range
Whirlpool Corporation · Manufacturer documentation
Relied on for: That the control panel is cleaned with soap, water and a soft cloth or sponge, and then if needed with glass cleaner, mild liquid detergent, all-purpose cleaner or a nonabrasive scrubbing pad. (states this directly)
Soap is safe on, in specific conditions, Trainer upper
Safe only in specific conditions
This is only appropriate within specific limits, and nothing is established outside them.
Only within these limits:
- Mild soap in warm water, by hand, with a dedicated sponge or soft brush
- Do not soak or submerge the shoe
- Rinse the soap out thoroughly rather than leaving it in the fabric
- Not on a suede or nubuck upper, where water damages the nap
The clearance is for a synthetic mesh or knit upper. The same treatment on a napped upper is what another manufacturer warns against.
Evidence
Supported
Sources
Can I Put Shoes in the Washing Machine?
Altra Running (VF Corporation) · Manufacturer documentation
Relied on for: That the maker's hand method is warm water and mild soap with a dedicated sponge, with the soap rinsed out thoroughly and the shoe not soaked. (states this directly)
Shoe Care Tips: Nubuck and Suede
KEEN Footwear · Manufacturer documentation
Relied on for: That water damages the nap of suede and nubuck. (states this directly)
Soap is safe on, in specific conditions, Detergent drawer housing
Safe only in specific conditions
This is only appropriate within specific limits, and nothing is established outside them.
Only within these limits:
- Mild soap, water and a soft cloth or sponge
- A small soft brush inside the housing where build-up has set
- The housing is cleaned IN PLACE; only the drawer comes out
Evidence
Supported
Sources
How to Clean a Front Load Washer Dispenser (Drawer)
Whirlpool Corporation · Manufacturer documentation
Relied on for: That the dispenser drawer is removed and washed under warm running water with a soft brush, that the housing is cleaned with mild soap and a soft cloth, and that removable parts must not be cleaned in the dishwasher. (states this directly)
Soap is safe on, in specific conditions, Fridge shelf
Safe only in specific conditions
This is only appropriate within specific limits, and nothing is established outside them.
Only within these limits:
- Let the shelf reach ROOM TEMPERATURE first — this is the whole safety condition
- Then warm, soapy water
- Dry thoroughly with a microfibre or soft cloth before re-installing
- Both hands when lifting; the glass is heavy and impact breaks it too
The ordering carries the risk. The identical method is correct after warming and dangerous before, which a general answer about cleaning a fridge would not tell you.
Precautions
- Check the manufacturer's instructions
Evidence
Supported
Sources
Cleaning the Shelves - Refrigerator
Whirlpool Corporation · Manufacturer documentation
Relied on for: That glass shelves must not be cleaned with warm water while cold because they may break from sudden temperature change, and must be allowed to reach room temperature before applying warm soapy water and dried thoroughly. (states this directly)
Soap is safe on, in specific conditions, Fridge door seal
Safe only in specific conditions
This is only appropriate within specific limits, and nothing is established outside them.
Only within these limits:
- A damp cloth and mild soap
- Lift the folds gently to get the crumbs out
- Dry it fully, to help keep a tight seal
- No bleach, no abrasives, no window spray
Evidence
Supported
Sources
Cleaning the Interior of the Refrigerator
Whirlpool Corporation · Manufacturer documentation
Relied on for: That warm water with mild dish soap and a microfibre cloth is used, that gaskets are cleaned with a damp cloth and mild soap lifting the folds, that all parts must be completely dry before reinstalling, and that abrasives, window sprays, scouring cleansers, waxes, concentrated detergents, bleaches and petroleum-based cleansers must not be used on plastic parts, liners or gaskets. (states this directly)
Soap is safe on, in specific conditions, Crisper drawer
Safe only in specific conditions
This is only appropriate within specific limits, and nothing is established outside them.
Only within these limits:
- Take it out and wash it with warm water and mild dish soap
- Completely dry before it goes back
- Nothing on the maker's prohibited list, which rules out most stain removers
Evidence
Supported
Sources
Cleaning the Interior of the Refrigerator
Whirlpool Corporation · Manufacturer documentation
Relied on for: That warm water with mild dish soap and a microfibre cloth is used, that gaskets are cleaned with a damp cloth and mild soap lifting the folds, that all parts must be completely dry before reinstalling, and that abrasives, window sprays, scouring cleansers, waxes, concentrated detergents, bleaches and petroleum-based cleansers must not be used on plastic parts, liners or gaskets. (states this directly)
Soap is safe on, in specific conditions, Door liner
Safe only in specific conditions
This is only appropriate within specific limits, and nothing is established outside them.
Only within these limits:
- Spray the CLOTH lightly, as the maker directs, rather than the liner
- A microfibre cloth with a mild soap solution
- Dry afterwards
Precautions
- Disconnect from the power supply first
Evidence
Supported
Sources
Cleaning the Interior of the Refrigerator
Whirlpool Corporation · Manufacturer documentation
Relied on for: That warm water with mild dish soap and a microfibre cloth is used, that gaskets are cleaned with a damp cloth and mild soap lifting the folds, that all parts must be completely dry before reinstalling, and that abrasives, window sprays, scouring cleansers, waxes, concentrated detergents, bleaches and petroleum-based cleansers must not be used on plastic parts, liners or gaskets. (states this directly)
Why
- Soap is explained by Surfactancy
- Soap is explained by Saponification
- Soap is explained by Insoluble metal soaps
- Soap is explained by Water hardness
- Soap is explained by Soap versus detergent
- Soap is explained by Why the recommendation is usually the mild one
Aftercare and prevention
- Soap requires the aftercare Finished wood flooring
Rewax once the wood has dried completely. The cleaning removes the protective wax coating, so stopping at the clean leaves the surface less protected than before it was touched.
- Soap requires the aftercare Stainless steel
Dry it. Water left to evaporate on stainless can mark it, and the mark comes from the water rather than from the dirt.
Sources for this page
Sources
Handbook of Detergents (Surfactant Science Series)
CRC Press / Taylor & Francis · Reference work
Relied on for: That water hardness reduces detergency through the interaction of calcium and magnesium ions with surfactants, and that builders and chelants address it. (background and mechanism only)
Kirk-Othmer Encyclopedia of Chemical Technology
John Wiley & Sons · Reference work
Relied on for: That soaps are salts of fatty acids and that their calcium and magnesium salts are of low solubility. (background and mechanism only)