There are many types of cat litter on the market, clay, “scoopable’, and clumping sand make up most of the brands. The problem with these is that the clumping ones use a chemical that is a bonding agent that is like cement and actually expands and should not be flushed as it can cause plumbing problems, not to mention if you have an animals that eats feces, this clumping litter can be harmful to the animal’s digestive system by causing blockages when the litter swells.
The clay litter contains Crystalline Silica that is carcinogenic when the dust is breathed in causing Silicosis. It is also non-biodegradable. Many clumping litters contain sodium bentonite which is the agent that bonds the litter. If it is in the brand you buy, it is hard on plumbing and can cause problems if animals eat any of it. Ant they cannot be composted.
The best and safest cat litters to use are plant-based litters. Plant-based litters are compressed pine, newspaper, corn cob, and one that many people do not think of, Wood Stove Pellet Fuel. Plant-based litters are biodegradable, safe for the environment, and there is little dust to worry about. It may take some time for your cat to become used to this change, but they will and like it.
The wood stove pellet fuel is inexpensive, easily found in a local hardware, or online. This is the same fuel that is used in some models of barbeques. It breaks down into sawdust and is lighter to handle than most clay or scoopable litters, with a good deal less mess. It is also easy to tell when to change it, and it does hold down the smell in the litter box.
An animal rescue used it for multiple cats and it worked well for them. This is just something to think about