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One of the most commonly asked questions that we get at this website, is can you flush cat litter down a toilet? There are obvious benefits in doing this, and that is especially true if you also keep your cat litter box in the bathroom, or close to the bathroom. However, there are quite a few valid reasons why you should never consider doing this.

Clay based cat litter should NEVER be flushed down a toilet under any circumstances whatsoever, and it does not matter which type of clay cat litter you use. Most cat litter, and especially the clumping variety will block up waste pipes and cause you major plumbing problems. There are also huge health risks by flushing cat feces and urine into the main waste.

Those are the two main reasons why cat litter should not be flushed down a toilet. I will go into this in more detail in this article as that will help explain the importance of this to cat owners. As a general rule though cat litter should be disposed off in the normal trash, as it is also not suitable for recycling, nor should it ever be used as a general compost.

Some natural or biodegradable litters can be flushed, but even with these litter types some care has to be exercised, as I will explain later in this article.

I know that I have summarised above a number of individual problems with flushing cat litter, and in the remainder of this article I will break those problems down. Hopefully from that you will get a much better understanding of the problems of flushing cat litter down any type of waste pipe.

Health Risks by Flushing Cat Litter

This is the most important reason why any responsible cat owner should think carefully before flushing cat litter down the toilet. Cat poop may contain parasites, and may also contain dangerous substances which can impact on water treatment and sewage plants.

This may actually sound like a huge over statement so please allow me to explain.

All pet waste, and that of course includes cat waste is classified as a pollutant by the Environment Protection Agency. In particular, they refer to the viruses, bacteria and nutrients found in pet waste. Their reason for this is and I quote from their literature:

“These pollutants can harm fish and wildlife populations, kill native vegetation, foul drinking water, and make recreational areas unsafe and unpleasant.”

In addition to this some cats may be infected with a disease known as Toxoplasmosis. When that happens then cat waste will contain a parasite known as Toxoplasma gondii. If humans come into contact with a cat with Toxploasmosis, then most humans can fight this off as our immune systems are quite strong. Those with a lower immune system, such as a pregnant woman, may however become infected.

If it does happen to a human the symptoms can be similar to those that we get with a bad flu. That includes the typical aches, pains and a hot fever. Pregnant women should be extremely aware that this can cause some serious fetal development disorders, such as loss of eyesight, brain damage, premature birth and even still born death.

If you would like to find out more about pregnancy and handling cat litter, then please read this article.

For now though, let’s get back to flushing cat litter down a toilet. If cat waste is flushed down a normal household toilet, and the cat is carrying this parasite the waste is essentially being placed into the normal waste system. It will eventually get to a waste treatment plant. There are a lot of waste treatment plants that simply can not treat that kind of harsh parasite and pollutant.

Now in terms of measuring this risk it is important to put the risk into some perspective. The risk is considered to be small as few cat owners actually flush cat litter down a toilet. The number of cats with the parasite is also a small number. That means the risk is low to humans. Nevertheless it still remains a dangerous risk, especially for anyone with a reduced or weakened immune system.

In addition to this public waste systems have been upgraded and can now deal with this parasite. That said not all waste plants can. The bottom line is that it is recommended that cat owners should not flush cat poop down a toilet.

Cat Litter – Flushing & Plumbing Problems

As you may already know there are different types of cat litter available on the market. These include:

  • Clumping cat litter
  • Non-clumping cat litter
  • Silica Gel cat litter
  • Natural or biodegradable cat litter

I will explain the key differences in these, and then explain why some are more dangerous than others to flush down the toilet.

Flushing Clumping Clay Cat Litter

This is by quite a distance the most popular type of cat litter and is used by the vast majority of cat owners. This is a clay based litter that is designed to form hard clumps when it comes into contact with water or moisture. This is the worst type of litter that you could attempt to flush. You should never flush this litter type into your waste system.

That is because it swells and expands as it absorbs moisture. Flush this down a loo and over time it will form into a hard lump. Some of these clumping litters can actually swell to thousands of times their natural size.

That will cause a blockage in your waste pipes and can be quite a costly fix. Plumbing costs are never cheap, and trying to locate and fix the blockage will cost you a lot of time and money.

Flushing Non-Clumping Cat Litter

This type of litter is also a clay based litter. It doesn’t swell up though so not as dangerous as the one described above. Nonetheless it is made from clay and when flushed remnants of this will remain in the waste pipes. Over a longer period of time this will also build up, and could cause a blockage over time.

With a clumping litter the blockage in waste pipes will happen pretty quickly. With the non-clumping type the build up of litter will take longer, but it will eventually block.

Flushing Silica Gel Cat Litter

If you are not familiar with silica gels litters, these are made from silica and are usually in the form of round crystals. They look like round balls and are quite messy if they get spilled. Many cat owners are now starting to use those in preference to the clay based litters.

However like the clumping cat litter these are also designed to absorb moisture. Like the clumping litter they will swell and they can cause major blockage problems. Some of these crystal litters clump and some don’t. Either way they are not suitable to be flushed down a toilet.

What Cat Litter is Flushable?

If you have read this article so far, you will know that flushing a clumping clay litter will be very detrimental to your plumbing. Aside from that you will also be aware that there can be serious health risks in doing that as well. Now some manufacturers claim that they make litter that can be flushed.

There are self-flushing litter toilets which are expensive. They use what are called washable granules. The granules sit in the bottom of the cat toilet and get washed rather than get flushed. This is not actually a clay or silica gel litter. The manufacturers of these call them washable granules, which have the same look and feel of litter.

The washable granules are made of plastic. However some buyers do complain that some of these can get flushed down the toilet when the self-flushing cat litter is in operation. So that means there is a risk of your waste pipe getting blocked from a build up of these plastic granules.

There are also many cat owners who also state that it is safe to flush natural or biodegradable litter. I would challenge that strongly. There are two reasons why I would do that:

  1. There is still the health risk from an infected cat of Toxoplasmosis
  2. There is still a risk of blockage of the pipes over time.

I have explained this in more detail just below. Many natural or biodegradable litters are strongly advertised as being flushable. These types of litters are made from materials like corn husks, coconut husks, wheat, recycled paper, wood shavings etc. Some of these clump and some do not.

Check out the video below where you will see that the only thing you should put down your toilet is human waste and toilet paper. If you want to see what so called “flushable litter” does, then you will find that experiment at around the 4 minute mark. Spoiler Alert (It doesn’t flush away)

Is Flushable Cat Litter Really Flushable?

You have seen my answer to this just above. In my opinion no cat litter should be flushed if it contains cat poop. That is because of the risk of getting infected cat poop into the main human waste system.

When it comes to the actual litter itself, then in my opinion, none of them are 100% completely safe to flush.

Self Flushing Litter Boxes

The granules used in the self-flushing litter boxes are supposed to stay in the toilet and to be fair most of these do. They are not supposed to be able to flush away. The reality is that quite a number of the people who own this type of litter say that can happen. Now it can happen to a greater or less degree. Either way you are pushing plastic granules into your waste. There is no evidence one way or another if this can actually clog pipes.

I would imagine in the short term the risk would be very low. However in the medium to long term, the risk simply has to increase.

Clay & Crystal Litters

The very clear answer here is that these two types of litter should never be flushed as they will block waste pipes.

Natural or Biodegradable Litters

Many manufacturers advertise these natural litters in two ways. They state they can be flushed and they also state they can be used for compost. Yes they can do that though not if there is poop in them. If the poop has been removed then they can be used in compost heaps.

When it comes to flushing the risk is left to you. For me anyway, any natural cat litter that clumps, will in my opinion also clump in your waste pipe. It is not something that I would risk doing myself.

What to do if you Flush Cat Litter?

The first thing you should do is hope that it doesn’t start to clog. If the amount was not huge then you may be lucky enough to get away with it. Nevertheless, it would be a good idea to get a plunger, use that and see if it gets out any of the litter. If it does you can then remove it, though that will certainly not be a pleasant task.

If the litter has clumped further down the pipes you may need something like drain rods to try and get it out. More often than not though you will have to call a plumber and pay the hefty price.

Can You Flush Cat Poop in a Septic System?

You will not be that surprised to know that you can’t flush cat litter in a septic toilet system either. The same basic rules apply and cat litters will clog up the pipes in septic systems as well as in ordinary waste management systems. Now again the manufacturers of natural litters state they are septic friendly.

There are a few septic system types including the basic gravity, pressurized and proprietary systems. No matter which septic system you have, they all use pipes of some kind for the waste disposal. If these get blocked that can certainly be an expensive fix.

Some septic systems also use pumps and again cat litter can block those pump inlets and outlets. The advice from every septic system manufacturer is to never flush wipes, garbage, feminine hygiene products, cat litter, cat waste, bleach, strong cleaning products, paint, unused medicine, and water softeners.

That is because all of these can quickly and easily block your septic system.

How to Unclog Cat Litter from a Toilet?

This can be a very difficult task for a couple of reasons.  The first big problem is trying to find the actual blockage. Locating the actual blockage can be both frustrating and very time consuming. In some cases the pipe can be blocked under the ground and in the worst scenario, may require a lot of digging to locate.

The second problem is that once you do find it, it needs to be unblocked and I assure you that is one of the most unpleasant things you will ever have to do. It truly stinks and I would always recommend paying a professional to do this, even though it will cost a lot of money.

If a toilet does get clogged the first thing to try is a plunger. If that fails then try a commercial drain unblocker and see if that works. If not you will have to call a plumber.

How To Dispose of Cat Poop

The only proper and safe way to dispose of cat waste is to put it into a plastic bag and then into your main waste bin. Yes that will go to a landfill site which I know is not that good for the environment. However the alternatives to this are certainly more dangerous.

  • You can never use cat waste to make compost or as a fertilizer for your garden. (Some natural cat litters can) If you want to know why, then check out my article on cat litter and composting. 
  • Cat litters definitely cannot be recycled
  • It can’t be flushed for the reasons explained in this article

That means the only way to get rid of it is to scoop it, bag it and dump it. This is currently the safest way to dispose of cat litter safely.

Useful Resources

United States Environmental Protection Agency

Toxoplasmosis Explained at Wiki