How to remove baby sick from limestone
- DifficultyModerate
- OutlookOften removable
- MaterialLimestone
- Reviewed7 September 2026
The short answer
Blot it up with kitchen roll rather than wiping, then wash with a little washing up liquid in warm water, which is the stone trade body's routine clean. Anything that has soaked in needs a poultice: bicarbonate of soda mixed with 3 percent hydrogen peroxide, covered and left for a day. Never use vinegar, lemon juice or a limescale remover on limestone, at any dilution.
If it has just happened
Blot it up with kitchen roll rather than wiping. Limestone is porous, so the clock starts immediately and how fast you get the liquid off decides how much soaks in.
Never combine hydrogen peroxide with vinegar
Mixing hydrogen peroxide and vinegar makes peracetic acid, which irritates skin, eyes and airways. Both appear in stone cleaning advice for different purposes, so keep them apart: use one, rinse the surface, let it dry, and only then use the other if you genuinely need to. The stone trade body gives the same warning about bleach and ammonia, which together produce a toxic gas.
Heat can set this stain permanently
Do not use hot water, a tumble dryer, an iron or a steam cleaner until the mark has gone. Heat fixes this type of stain into the fibres and makes it far harder to shift.
Test on a hidden area first
Try any cleaner on a hidden part of the material first, such as a seam, an offcut, inside a hem or under a piece of furniture. Wait for it to dry and check for colour change before treating the visible mark.
Cleaning the mark is not the same as disinfecting
If the sickness came with a stomach bug rather than an ordinary posset, the surface may carry norovirus, which spreads easily and survives on hard surfaces. UK public health guidance is to wear gloves, avoid shaking contaminated laundry, wash affected laundry separately with normal powder at 60 C where the care label allows it, and disinfect compatible hard surfaces with a bleach based product afterwards. Do that after the stain work, not instead of it, and only where the material tolerates it.
Keep every kind of drying heat away until the mark has gone
Baby sick is mostly milk protein. Heat coagulates protein and locks it into the material, which is why a mark that would have washed out can become permanent after one hot wash, one pass with an iron, a hairdryer or a spell on a radiator. Cool or warm treatment, air drying, and a proper look in daylight before anything warm goes near it.
What you will need
- Disposable gloves Sickness that came with a stomach bug is a hygiene job as well as a stain.
- A plastic spatula or a spoon Plastic, not metal. Metal scores stone and leaves a grey mark on pale surfaces.
- Kitchen roll and soft cloths For blotting rather than wiping, because wiping spreads a spill across more porous surface.
- Warm water and washing up liquid A little mild detergent in warm water is the routine clean the stone trade body specifies.
- Bicarbonate of soda The absorbent half of a poultice, and the safe way to lift a mark out of a porous stone.
Helpful but not essential
- Hydrogen peroxide, 3 percent The active half of a poultice. The stone trade body names peroxide for organic stains.
- Cling film and masking tape To stop a poultice drying out in the first few hours.
Fresh baby sick on limestone
Speed decides how much soaks in, and blotting decides how far it spreads.
Go carefully with warm water
Limestone tolerates warm water only within limits. Keep contact time short, work from the edge of the mark inwards and stop if the material changes.
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Blot, do not wipe
Press kitchen roll onto the spill and lift. Wiping spreads it across more stone, and porous stone absorbs everything it touches.
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Lift the solids with a plastic spatula
Plastic rather than metal, because metal scores stone and leaves a grey graphite-like mark on pale surfaces.
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Wash with mild detergent and warm water
A soft cloth with a little washing up liquid in warm water, which is the routine clean the stone trade body specifies. Rinse with clean water and dry with a soft cloth.
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Look at it again once it is properly dry
Stone looks darker while it is damp and can look clean when it is not. Give it a few hours, look in daylight, and only then decide whether anything has soaked in.
Dried baby sick on limestone
A poultice draws the mark back out of the stone. It takes a day and there is no faster version.
Go carefully with warm water
Limestone tolerates warm water only within limits. Keep contact time short, work from the edge of the mark inwards and stop if the material changes.
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Clean and dry the area first
Mild detergent and warm water, then let it dry completely. A poultice on a dirty or damp surface works on the dirt rather than on the stain.
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Mix the poultice
Mix bicarbonate of soda with 3 percent hydrogen peroxide into a paste about the consistency of thick yoghurt. The stone trade body names hydrogen peroxide for organic stains indoors, and baby sick is an organic stain. Do not add vinegar or any acid to it.
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Cover it and leave it
Spread the paste about half a centimetre thick over the mark and a little beyond it, cover with cling film taped at the edges, and leave it for a day. The film stops it drying out in the first few hours, which is when it does most of its work.
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Lift it off and let the stone dry
Take the film off, let the paste dry completely, then lift it with a plastic spatula and wash the area. Judge the result only when the stone is dry.
Old or set in baby sick on limestone
Repeats are normal. Knowing when to stop is the useful part.
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Repeat the poultice, fully dry in between
Stone specialists describe two or three applications on an older mark as normal rather than a sign that anything is wrong. Let the stone dry completely between them.
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Check whether it is a stain or damage
A stain is darker than the stone around it. Etching is duller rather than darker, and it is acid damage to the surface. No poultice touches etching.
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Look at it dry, in daylight
Damp stone is impossible to judge. Every decision here is made on dry stone by a window.
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Then call a stone restorer
They can hone and repolish an area, which is a different set of tools rather than a stronger bottle. On a floor, a worktop or a fireplace, a patch that does not match is worse than the mark, so this is a judgement worth paying for.
What not to use on limestone
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Scouring powder, cream cleaner and wire wool
The stone trade body warns that scouring powders and creams contain abrasives that scratch stone. On a polished or honed surface that shows as a permanent dull patch, which is worse than the stain.
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Wiping a fresh spill rather than blotting it
Wiping spreads liquid across more porous surface, and every extra square centimetre it touches is more stone for it to soak into.
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Mixing bleach and ammonia, or peroxide and vinegar
The stone trade body warns specifically that bleach and ammonia must never be mixed. Peroxide with an acid makes peracetic acid. Both combinations appear in stone cleaning advice for different purposes, so keep them apart.
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A steam cleaner
Steam forces moisture into a porous stone and into the joints, and heat sets milk protein at the same time.
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Vinegar, lemon juice, limescale remover and acidic bathroom sprays
Acid dissolves the surface rather than marking it, leaving a dull etched patch that no cleaner removes because the polished layer has gone. Dilution and speed do not change this.
White compared with coloured limestone
Hydrogen peroxide is the chemical the stone trade specifies for organic stains and it lightens as well as cleans. On white and pale limestone that is invisible. On darker or heavily veined limestone it can leave a lighter patch, so test on an offcut or a hidden edge and let the test dry completely before treating anything visible. The plain bicarbonate and water poultice is the slower alternative that carries no bleaching risk.
Products that genuinely help here
Try the household route above first. These are worth buying only when it is not enough.
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Optional product
Pure Safe hydrogen peroxide 3 percent solution, 500 ml
The active half of a poultice
Baby sick is an organic stain, and hydrogen peroxide is what the stone trade body names for organic stains in stone. There is no household substitute for it in a poultice, and the bicarbonate of soda that makes up the other half is already in most kitchens.
Worth knowing. Never combine it with vinegar or any acid, which makes peracetic acid. Buy it fresh, because it weakens in the bottle.
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If the mark is still there
A poultice normally needs repeating. The stone trade body describes leaving one on for a day or two, and stone specialists treat two or three applications on an older mark as normal rather than as a sign that something is wrong.
Between applications, let the stone dry fully. Damp limestone looks darker and it is impossible to judge progress on it. Look at it dry, in daylight, and only then mix another batch.
If three full poultices have not moved it, stop. Also check what you actually have: if the area is dull rather than dark, that is etching from an acid at some point, not a stain, and no poultice will touch it.
When to stop and call someone
Call a stone restorer rather than continuing if three poultices have not shifted the mark, if the surface is dull or rough as well as marked, which is etching rather than staining, or if the limestone is a floor, a worktop or a fireplace where a patch that does not match would be worse than the stain.
Why baby sick behaves this way on limestone
Limestone is calcium carbonate and it is porous. Both facts drive everything here.
Porous means it soaks in
A milk mark does not sit on the surface, it goes into the stone. Wiping the top clean leaves the mark below, which is why a spill that looked dealt with reappears as a shadow the next day. A poultice reverses that: a wet absorbent paste on top draws the liquid in the stone up into itself as it dries, bringing the stain with it. That is slow by nature and cannot be rushed.
Calcareous means acid is out
Vinegar, lemon juice, limescale removers and acidic bathroom sprays all react with the surface, dissolving a microscopic layer and leaving a dull mark called etching. That is not a stain and it does not clean off, because there is nothing on the stone to remove.
Why peroxide
Baby sick is organic, and hydrogen peroxide is what the stone trade specifies for organic stains. It is not an acid in any practical sense, so it does not etch.
Why nothing hot
Milk protein sets with heat, and warm stone dries a poultice out before it has done its work.
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Sources
What we checked and when. Where a manufacturer instruction disagrees with anything here, follow the manufacturer.
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Care and cleaning of natural stone, Natural Stone Institute
trade body
Stone trade body guidance that calcareous stone such as limestone and travertine is sensitive to acid so only mild non acidic cleaners are used, that acidic cleaners are still not advised on granite, slate or sandstone because they can hold acid sensitive minerals, that scouring powders scratch stone, that the routine clean is a neutral cleaner or mild washing up liquid in warm water, that organic stains are treated with hydrogen peroxide, and that ammonia and bleach are never mixed.
Checked 7 September 2026
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Sick happens: how to get vomit out of carpet, National Carpet Cleaners Association
trade body
UK carpet cleaning trade body method for vomit: scrape solids with a blunt spatula or spoon, apply equal parts white vinegar and water, blot gently working towards the middle of the mark rather than outwards, never scrub because that drives the vomit deeper and damages the carpet, use only a small amount of warm water on a dried mark, and expect rehydrating it to release the smell again so ventilate.
Checked 7 September 2026
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How to remove baby formula stains, Purex Stain Lab
manufacturer
Manufacturer guidance identifying breast milk, formula and baby spit-up as protein stains, explaining the role of enzymes, and warning that the mark should be checked before any drying heat because heat sets what remains.
Checked 7 September 2026
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Norovirus: what to do and how to stop the spread, UK Health Security Agency
authority
UK public health guidance establishing that illness related vomit can carry norovirus, that contaminated laundry should be washed with normal powder at 60 C where the care label permits, and that compatible hard surfaces should be disinfected with a bleach based product.
Checked 7 September 2026