Is Your Cat Litter Hurting the Planet? The Environmental Impact of Kitty Litter

Cat litter is essential for cat owners to absorb urine and feces in litter boxes, helping keep homes clean and odor-free. However, most cat litter is made of clay, silica gel, or other synthetic materials that do not biodegrade easily and take hundreds or thousands of years to break down in landfills. With millions of cats in households across the country generating tons of litter on a daily basis, cat litter takes a heavy toll on the environment if not disposed of properly. This article provides an overview of the environmental impact of cat litter and tips for cat owners to reduce their litter footprint.

What Cat Litter is Made Of

Cat litter is typically made from a variety of natural and synthetic materials that can absorb moisture, trap smells, and make cleanup easy. The most common materials used are:


Clay is one of the most popular cat litter materials. Clay litters are made from bentonite, a naturally clumping clay that forms into solid clumps when wet. This allows solid waste to be easily scooped out and disposed of. Clay litter is very absorbent and effective at controlling odors. However, some cats dislike the texture of clay litter. Examples of clay litters include Tidy Cats and Dr. Elsey’s Ultra.

Clumping clay litters are generally safe for cats if ingested in small amounts as the clay is natural. However excessive consumption can cause blockages (Catster).

Silica Gel

Silica gel litters are made from silica dioxide sand that is hydrated with oxygen molecules. The porous structure of silica gel makes it extremely absorbent while remaining lightweight. Silica gel litters do not clump, instead allowing liquid to pass through and evaporate from the crystals. This leaves solid waste on top for easy cleaning. Silica gel litters produce less dust and may be preferable for cats with respiratory issues. However, they are not biodegradable like clay.

Crystalline silica dust from litter is dangerous if inhaled in high concentrations over time. However, reputable brands use amorphous silica gel which does not carry the same risks (Cloud Pet).

Clay Cat Litters

Clay cat litters are one of the most common types of cat litter. They are made from clay that is strip mined from the earth. The clay is then processed and baked into granules suitable for cat litter. While clay itself is a natural material, the strip mining process can damage landscapes and clay cat litter itself is not biodegradable. Once clay cat litter is discarded, it will sit in a landfill indefinitely. According to, the strip mining and lack of biodegradability of clay cat litters raises environmental concerns. Alternatives that are more eco-friendly may be preferred.

cat litter box with clay litter

Clumping Clay Litters

Most popular conventional clay litters are clumping varieties made with sodium bentonite clay. The clay forms clumps when wet, allowing easy scooping and removal of urine and feces. However, the sodium bentonite is strip mined from the earth and requires substantial processing with dangerous chemicals like sulfuric acid. The clumping action relies on the exchangeable sodium ions in the clay, which means the used litter has high sodium content.

When flushed or discarded in landfills, the sodium bentonite clay can release damaging levels of sodium into waterways and oceans. Excess sodium is highly problematic for marine life and freshwater ecosystems, harming the gills and bodies of fish and other aquatic animals ( The manufacturing process also contributes to deforestation, erosion, flooding, and general environmental degradation in mining areas.

Silica Gel Litters

Silica gel litters are made from silica dioxide sand, which is a non-renewable resource. However, they tend to be more environmentally friendly than traditional clay litters in some ways. Silica gel absorbs urine and controls odors very effectively. This means the litter needs to be changed less frequently than clay litter, resulting in less waste overall.

Additionally, silica gel litters produce less dust than clay litters. The granules are larger in size and don’t track outside the litter box as easily. Silica gel is also non-clumping. Rather than forming clumps, the granules absorb liquid until they reach saturation, then can simply be disposed of.

While silica sand needs to be mined, it is an abundant resource. Silica gel litters are estimated to last twice as long as traditional clay litter before needing to be replaced. So they ultimately use less litter material over time. This makes them one of the more eco-friendly disposable litter options.

Biodegradable Litters

Biodegradable litters are made from plant-based materials like wood, paper, or corn. Unlike clay litters, they can break down through natural processes and composting. According to The Green Pet Shop (, biodegradable litters are designed to be safe for the environment.

Most biodegradable cat litters are compostable as well. Compostable litters made from plant materials can fully decompose into organic matter like soil or fertilizer, usually within 90-120 days according to the experts at The Spruce Pets ( This makes biodegradable litters a more eco-friendly choice compared to clumping clay.

Some popular biodegradable cat litter options include wheat, pine, corn, and walnut shell litters. Biodegradable litter brands like Swheat Scoop, Feline Pine, and World’s Best Cat Litter can reduce plastic waste from traditional clay litters. However, some biodegradable litters may still contain silica dust or fragrances, so check labels carefully.

Disposing of Used Cat Litter

The most common way to dispose of used cat litter is by placing it in plastic bags and throwing it in the trash to be taken to landfills. However, this contributes to plastic pollution as the bags do not readily break down. Even litter that is biodegradable can take a very long time to decompose in the anaerobic conditions of a landfill [1].

person disposing of used cat litter

Some people flush used clay litter down the toilet, but this can clog plumbing over time as the clay clumps together. Flushing litter also adds more waste to water treatment systems. Silica gel litter should never be flushed [2].

A better solution is to compost biodegradable litters at home or through a municipal green waste collection program. Look for litters made of materials like corn, wheat, pine, or other plant-based products. Scoop out solid wastes before composting. Compostable litter bags are also available. For other types of litter, reusable containers or biodegradable bags reduce waste [3].

Reducing Your Cat’s Litter Impact

There are several ways cat owners can reduce the environmental impact of their cat’s litter:

Switch to a natural, biodegradable litter made from materials like wood, paper, or plant fibers. Popular options include wheat litter, pine litter, and corn litter. These break down naturally over time. Just be aware that some cats don’t like the texture or smell of natural litters (1).

Look for compostable litters made from renewable materials like bamboo or grass seeds. Some can be flushed or composted at home. Compostable litters include World’s Best Cat Litter and Swheat Scoop (2).

Reduce waste by choosing a clumping litter rather than non-clumping. Clumping litters allow you to scoop out solid waste without dumping the entire box. Reusable litter systems like Litter Robot also cut down on waste.

Consider litter alternatives like pellet systems that separate waste and reuse litter material. The CatGenie litter box hooks up to your plumbing to wash away waste and reuse litter pellets (3).

Buy in bulk sizes or subscribe to litter delivery services to reduce packaging waste from small bags. Opt for recyclable packaging when possible.

Properly dispose of used litter by sealing it tightly before placing in the trash. Some communities accept cat litter for composting. Never flush clay or clumping litters, as they can clog pipes.

Considering Alternatives

There are some alternatives to traditional clay and silica gel litters that can reduce the environmental impact of cat waste. Some options to consider include:

biodegradable pellet cat litter

Pellet Litters

Pellet litters are made from biodegradable materials like pine, wheat, or newspaper. The pellets break down when exposed to liquid, forming a solid clump that can be scooped out. Brands like Feline Pine and Swheat Scoop make pellet litters that are compostable and use less non-renewable resources than clay.

Robotic Litter Boxes

Robotic or self-cleaning litter boxes automatically separate waste after your cat uses them, reducing the amount of litter used. They work by rotating an internal tray or conveyor belt to filter out solid waste into a compartment that can be discarded. Popular models include the Litter Robot and PetSafe ScoopFree.

Silica Gel Crystals

Silica gel crystals are a relatively new type of litter made from sand. They are highly absorbent, lightweight, and produce less dust. The crystals can be flushed down the toilet, avoiding landfill waste. Brands like PrettyLitter feature renewable, sustainable sources of silica.

Using an environmentally friendly litter material that is compostable, biodegradable or recyclable can make cat waste disposal much more sustainable.


In conclusion, the environmental impact of cat litter depends on the type of litter and how it is disposed of. Traditional clay litter is mined and strip-mined clay can harm habitats. Clumping clay litter also contains bentonite clay that does not break down. Silica gel litters consist of plastic beads that persist in landfills. While biodegradable litters aim to be eco-friendly, many still contain some non-biodegradable materials.

The key ways to reduce the environmental footprint of cat litter include:

  • Opt for plant-based natural litters like pine or wheat that can biodegrade
  • Look for litters made from recycled materials
  • Dispose of litter properly by sealing bags and not flushing litter
  • Use litter sparingly and remove solids regularly
  • Consider DIY litter options like pellet stoves pellets

With some mindfulness of materials and disposal, cat litter can be managed to minimize environmental harm. The ideal solution is a natural, biodegradable litter produced sustainably.

cat using eco-friendly litter box

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