Types of Cat Litter, When and How to Switch

Anyone who lives with a companion cat can attest to the myriad of cat litter options these days. Yet, many cat caregivers default to the brand they know their cats will use. That’s usually the brand they have purchased for years. Indeed, switching cat litters can create a cascade of issues like a cat doing his “business” outside the box (called litter box aversion).

However, several of the newer cat litters are more eco-friendly and made from renewable resources. If you have the time and patience, we encourage you to give these a try. In fact, transitioning might not be as hard as one would suspect. We’ll give you tips on switching, but first let’s go over the current cat litter options on the market.


Clay cat litter is possibly the best selling on the market. You have two types of clay cat litter: clumping and non-clumping. Bentonite clay forms into clumps when a cat urinates. Non-clumping clay cat litter is made from clays other than bentonite.

Unfortunately, clays of any kind are not very eco-friendly:

  • Strip mined
  • Heavy – Transportation costs – and thus gas usage – are exponentially high since the clays are so dense. Plus, there are multiple steps along the way to get to your home. The clays go from the mine, to the production facility, to the warehouse, to the store and then to your home.
  • Production – The clays have to be mixed with other materials and involve many machines. It is an energy-intensive process.
  • Not biodegradable – Even if your household waste eventually ends up in an aerobic landfill, the clay-based litters will still not break down.
  • Swelling – Clumping clay can swell up to 15 times its original size once a cat defecates or urinates on it. This takes up room in the landfill.
  • Air pollution – Can release dust
  • Non-renewable resource

Silica Gel Crystals

You know the little packets of silica that say “do not eat”? According to poison control, silica gel is chemically inert and is considered to be non-toxic. The issue is that it could be a choking hazard. Then again, when a cat ingests them over time from paw licking, it could pose a problem.

Anyway, the silica crystals used in these types of cat litters are similar to the silica in packets. In general, silica is used for moisture control, is absorbent, controls odor and is dust-free.

More Eco-Friendly Cat Litters

Bear in mind that if your cat or anyone in your household has a food, inhalant or contact sensitivity to any of these types of materials, it would be best to avoid them.

  • Corn – We love that it is a renewable resource, but corn dust contains aflatoxins (fungi). So, you might want to try this one last.
  • Grass – Low dust
  • Pine
  • Recycled paper – Dust-free. You can also make your own!
  • Recycled wood
  • Walnut shells
  • Wheat – Low dust

Other Cat Litter Considerations

Activated Charcoal

Activated charcoal helps reduce fecal odor. Before buying a cat litter with activated charcoal, know the source of the charcoal. Sources can be bone char, coconut shells, peat, petroleum coke, coal, olive pits or sawdust. We would avoid the cat litters mixed with activated charcoal derived from petroleum coke or coal.

Baking Soda

Baking soda is also added to many brands to reduce odor. One study demonstrated that cats preferred activated charcoal.

Fake, Synthetic Fragrance Smells

Several studies show that many cats do not prefer the synthetic fragrances. All these do is really make cat poop smell like cat poop covered in fake flower scents. Another issue is that we do not know the long-term health effects on cats. In humans, though, we know that these synthetic chemicals can have a detrimental effect on endocrine, immune and respiratory health.


An experiment tested three types of cat litter – clay, scoopable, and recycled newspaper – for the bacterial concentrations on cat paws. Recycled newspaper had the highest total number of colony forming units (1619), followed by scoopable (1342), and then clay (1005). While the results were not significantly different between the three, the researchers said that people with compromised immune systems may want to take the results into consideration when choosing a cat litter.

How to Transition Cats

We asked the friends of our Facebook page about their kitty litter usage and if they had switched. The answers covered the gamut from they tried but the cats weren’t having it, to transitioned slowly, to just made the switch with no problems.

Cat behaviorist, Pam Johnson-Bennett, recommends transitioning gradually. She points out that cats are creatures of habit. We admit, they can be picky (and adorable, of course)!

Pam says you need to give your cat time to adjust to the change. So, she suggests that you mix a small amount of the new litter in with the current one every day for several days. This changeover should typically take place over three to five days.

We think it would be great if you can transition to a more eco-friendly cat litter. We do know that the ultimate decision maker is your companion cat and we hope he is on board the eco-train with us!


Becker, Karen. “Cat Litter Box Mistakes That Owners Unknowingly Make” Bark and Whiskers, 23 Mar. 2015, https://www.barkandwhiskers.com/2015-03-23-nl-common-types-cat-litter/.

Johnson-Bennett, Pam. “Changing Cat Litter Box Brands.” Cat Behavior Associates, 20 Feb. 2019, http://www.catbehaviorassociates.com/how-to-change-brands-of-litter/.

Neilson, Jacqueline. “The Latest Scoop on Litter.” 360. 01 Mar. 2009, https://www.dvm360.com/view/latest-scoop-litter.

Scheer, Roddy, and Doug Moss. “What Are the Most Ecofriendly Cat Litter Products on the Market?” Scientific American, http://www.scientificamerican.com/article/green-friendly-cat-litter-options/.

Wolf, Wesley. A Comparison of the Number of Bacterial CFUs Found on Cats’ Paws. American Junior Academy of Sciences, 13 Feb. 2015, http://aaas.confex.com/aaas/2015/webprogram/Paper15229.html.

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