Is it true that toilet bowls cannot be cleaned with bleach?

We recently had an old toilet replaced with a new one, and was told by the shop that use of bleach might nullify the manufacturer’s warranty. Is it true?

What part of the toilet?

If it is the cistern, I can see why cleaning it with bleach may impact on the warranty as bleach could impact on metals and rubbers within the cistern. It is possible to buy in cistern tablets or cleaning agents which have a bleaching agent. I suspect that this is what the shop was taking about. This is outlined in this warranty for a toilet available in Australia.

If it is the ceramic bowl, then bleach should no impact. Bowls are glazed and the coating will be resistant to the use of bleach. So much so, that many toilet cleaners contain bleach (sodium hypochlorite).

It is best to look at the warranty provided with the cistern/toilet to see what it says, and I would be very much surprised if the warranty was voided with using a bleaching/cleaning agent directly in the toilet.


The short answer is yes - and more. Read your toilet manufacturers T&C because most can refuse a warranty claim on a toilet for lots of things we all take for granted.

The warranties generally limit it to plastic parts (seats and flush mechanism).

Two representative snips re bleach and bleach containing products:

  • Never use cleaners containing abrasives, ammonia bleach, acids, waxes, alcohol or partsas they may damage the finish. Use of harsh cleaning agents may void warranty obligations.

  • DO NOT use bleach or products containing bleach (this will void your warranty)

Be aware that the in-tank toilet cleaners are included in most texts because they contain bleach. The issue is it can damage the surface, and possibly to low quality finishes.


Thank you Phil and phb.


I should have also said that if the ceramic glaze didn’t coat the whole of the porcelain bowl (a poor quality or poorly manufactured toilet), then bleach could enter the porcelain causing it to lose it strength over time. This is also likely water and other contents (esp. urine) would do likewise over time.

Any porcelain which did have missing glazing would stain easily, especially from water contaminants such as iron or from microbial growth.


Thanks again, but this is a Swiss product. It would be properly coated, I should hope.


Off at a tangent, but you just reminded me of the Vince from Shamwow advert from a decade or so ago: “…you know the Germans always make good stuff…”

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So would I, but noted for a recent new install.

If there is an upside the product boasts nano glaze technology for the cistern and bowl/pedestal. The warranty does include the porcelain subject to defects permitted by the Australian Standard as noted above.

Ref: Delta Back-to-Wall Toilet Suite – Fienza

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What about bleach that is going into a septic tank? I’m cautious about protecting the bacteria that do the work.

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It depends on the type of bleach. Chlorine bleaches are antibacterial and will kill your tank. I would not use anything unless it was clear that it was safe for septics.

As @syncretic said, don’t use chlorine bleach with a septic system. The bacteria the bleach kills include the ‘good’ ones in the septic tank.

Some other household cleaning products should be avoided, too. This article about what’s safe for septic tanks might be helpful: Cleaning products safe for septic systems |


Shannon Lush and Jennifer Fleming wrote a very good book on cleaning: “Spotless” - ABC books.

They recommend Bicarb, sponges, vinegar and a toilet brush. Sponges and vinegar for the cistern, lid and outside of the bowl; flush the toilet to wet the bowl, then apply bicarb liberally; then vinegar andf toilet brush. This old fashioned, cheap, effective approach is environmentally safe.

If that voids a warranty or damages the product, I’d suggest the warranty ought to be challenged under trade practices legislation or relevant state legislation as reasonable use.