Descaling Washing Machine

Is Sugar Soap a descaler, and can I use it to descale my washing machine?

No — Sugar Soap is not a descaler, and it is not the right product for a washing machine. Selleys Original Sugar Soap is a professional-strength, high-performance formula developed for cleaning walls and ceilings before painting and wallpapering. It is an alkaline salts-based cleaner. It may remove some scale build-up, but Selleys finds that it leaves a residue on hard surfaces such as glass or stainless steel — which is exactly what the inside of a washing machine drum is made of.

Selleys' recommendation for this job is to look at the alternate Hillmark range. Hillmark Scalex Plus descales and removes detergent residue, limescale deposits and calcium build-up from washing machines. It comes in individual sachets, so you have the exact amount needed for one machine clean rather than measuring out of a bottle.

Before you use it, check with your washing machine's manufacturer. Selleys is emphatic about this: not all washing machines are the same, and it is better to be safe.

Why an alkaline cleaner does not shift scale

This is the useful part of the answer, because it explains a mismatch that catches people out with other cleaning jobs too.

Selleys Original Sugar Soap has a pH of about 11 — strongly alkaline — and it is built to cut grease and grime. Grease responds to alkali. Limescale and calcium are mineral deposits, and they are a different problem entirely, which is why Selleys sends you to a dedicated descaler rather than a general cleaner.

The residue issue is the second half of the problem. Sugar Soap's own data sheet carries the instruction to rinse it well from glass before the product dries, because a salts-based cleaner that dries on a hard surface leaves a salts deposit. In a washing machine you cannot easily inspect or hand-rinse the internal surfaces, so a cleaner that is known to leave residue on stainless steel is the wrong tool regardless of how well it might cut the grime.

What Sugar Soap is actually for

Property	Typical result
Formulation	Alkaline salts based, professional strength
Colour	Clear blue
pH	Approx. 11
Density	Approx. 1.13 g/mL
Pack size	750 mL, makes up to 30 litres
Dilution	½ cup into 5 litres of water

Figures are indicative data only and are not intended for the preparation of specifications.

Its published uses are walls and ceilings before painting, floors, kitchen surfaces and appliances, bathroom surfaces, laundry tiles and sinks, and general outdoor items. That includes the outside of a machine and the laundry tub around it — just not the descaling job inside the drum.

How to approach the descaling job

1. Check with your washing machine's manufacturer first. Confirm that a descaling product can be used safely in your machine. This is Selleys' explicit recommendation and it comes before anything else.
2. Use a product made for the job. Hillmark Scalex Plus is what Selleys nominates. The sachet format means you use the right dose for one machine clean.
3. Follow the descaler's own directions for dose, cycle and temperature. Those come from the descaler's pack, not from this page.
4. Make it a routine. If your machine can take it, Selleys suggests descaling and rejuvenating the machine every 3 months to keep it running at optimum performance and prolong its life.

A quarterly interval is not arbitrary. Scale accumulates continuously in hard-water areas, and it builds on heating elements and internal surfaces where it reduces efficiency long before it becomes visible. Treating it on a schedule is much easier than removing a heavy deposit later.

Limitations to note

• Sugar Soap leaves residue on hard surfaces such as glass and stainless steel, which is why it is unsuitable inside a machine.
• Wipe it off immediately from aluminium and brass surfaces. Relevant to laundry fittings and taps.
• Rinse it well from glass before the product dries.
• Never mix it with another cleaner. Selleys does not recommend adding any other product to Selleys Original Sugar Soap.
• Its safety directions warn that it causes serious eye irritation; avoid contact with skin and eyes and wash hands after use.

Safety: what the classification behind that warning actually says

The limitations above note that Sugar Soap's safety directions warn about eye contact. It is worth stating the classification behind that warning precisely, because it is stronger than the word "irritation" suggests.

Selleys Original Sugar Soap is classified as hazardous under Safe Work Australia GHS 7 with the signal word Danger, on one classification: serious eye damage, Category 1 — H318, causes serious eye damage. That is the only hazard class assigned. There is no skin, inhalation or flammability classification.

No hazard data is reproduced here for Hillmark Scalex Plus, which is not a Selleys product. Read its own pack.

What H318 means for the way this product is used

Category 1 is permanent damage, not stinging that passes. The distinction matters because sugar soap has a reputation as a mild, old-fashioned product. It is alkaline at roughly pH 11, and alkali injuries to the eye are more serious than acid ones: an alkali keeps penetrating the tissue rather than self-limiting, so the damage continues after the splash.

The dangerous moment is the one nobody wears glasses for. This is a 750 mL concentrate that makes up to 30 litres, measured half a cup at a time into five litres of water. Decanting and diluting is when the liquid is at full strength, tipped at chest height over a bucket, before anyone has thought about eye protection. By the time you are washing a wall down, the solution is dilute and the gloves are on. Put the glasses on before you open the bottle.

An H318 splash is a 15-minute flush, not a rinse. Irrigate with copious water for a full fifteen minutes with the eyelids held open, then ring the Poisons Information Centre. Blinking it out and carrying on is what turns a treatable exposure into a permanent injury.

The instruction never to mix it with another cleaner is a chemistry instruction. If you are moving from Sugar Soap to a dedicated descaler on the same surfaces, rinse thoroughly and let the surface clear between the two rather than working one over the other.

For the appliance exteriors and laundry surfaces this product is listed for, there are lower-hazard options in the same range: Instant Sugar Soap is ready to use with no decanting step and carries only H319 (serious eye irritation, Category 2A), and Sugar Soap Wipes (H315, H319) involve no liquid to splash at all.

Poisons Information Centre — 131 126 in Australia, 0800 764 766 in New Zealand.

Common questions

Will Sugar Soap remove any scale at all?

It may remove some scale build-up, but it is not a descaler, and it leaves residue on hard surfaces such as glass and stainless steel.

What should I use instead?

Selleys recommends Hillmark Scalex Plus, which descales and removes detergent residue, limescale deposits and calcium build-up from washing machines.

Do I need to check with the machine manufacturer?

Yes. Selleys highly recommends checking with your washing machine manufacturer before using a descaler, because not all machines are the same.

How often should I descale?

If your machine can take it, every 3 months, to keep it running at optimum performance and prolong its life.

Why does Scalex Plus come in sachets?

So you have the exact amount needed to clean your washing machine, rather than estimating a dose.

Can I use Sugar Soap on the outside of the machine?

Sugar Soap's listed uses include appliances and laundry surfaces such as tiles and sinks. Keep it off bare aluminium and brass, and rinse it from any glass before it dries.

What about lime and calcium on bathroom tiles?

Same mismatch, same answer — see removing lime and calcium from bathroom tiles.

And mineral or rust staining on concrete?

See removing fertiliser rust stains from concrete, which is another job that needs an acidic cleaner rather than an alkaline one.

What is Sugar Soap best at, then?

Cleaning walls and ceilings before painting and wallpapering, and cutting grease and grime generally. See preparing ceilings for painting and top 5 Sugar Soap hacks.