Open main menu
A bag of litter and a basic litter box

A litter box, sometimes called a sandbox, litter tray, cat pan, or litter pan, is an indoor feces and urine collection box for cats, as well as rabbits, ferrets, miniature pigs, small dogs (such as Beagles and Chihuahuas), and other pets that instinctively or through training will make use of such a repository. They are provided for pets that are permitted free roam of a home but who cannot or do not always go outside to excrete their metabolic waste. Many owners of these animals prefer not to let them roam outside for fear that they might succumb to outdoor dangers, such as weather, wildlife, or traffic (indoor cats, on average, live ten years longer than outdoor cats).[1] A litter box makes it possible to shelter pets from these risks.

In the wild, cats naturally excrete in soft or sandy soil for easy burial. They use their paws in a backward sweeping motion to cover their feces. To stimulate this instinctive desire, a litter box's bottom is filled typically with an inch (2.5 cm) or more of cat litter. Litter box filler is a loose, granular material that absorbs moisture and odors such as ammonia. Some litter brands contain baking soda to absorb such odors. The litter material also satisfies a cat's instinctive desire to use an easily dug material. The most common material is clay, although recycled paper "pellets" and silica-based "crystal" variants are also used. Sometimes, when an owner wishes to stimulate the cat's natural instincts, natural dirt is used.

Types of litter box fillerEdit

In the US, cat litter is a $2 billion industry consuming five billion pounds (2.3 Mt) of mined clay annually.[2]

Non-clumping conventional litterEdit

The first commercially available cat litters in the United States was Kitty Litter, available in 1947 and marketed by Ed Lowe. This was the first large-scale use of clay (in the form of Fuller's earth) in litter boxes; previously sand was used. Clay litter is much more absorbent than sand and is manufactured into large grains or clumps of clay to make it less likely to be tracked from the litter box. The brand name Kitty Litter has become a genericized trademark, used by many to denote any type of cat litter. Today, cat litter can be obtained quite economically at a variety of retail stores. Conventional clay litter is indistinguishable from clay-based oil absorbent (used to clean oil spills); as the latter is far less expensive, it is often used as a substitute. Non-clumping cat litter is often made of zeolite, diatomite and sepiolite.

The cat-box that the litter is poured into can give off a strong odor. It is recommended that it is kept in an area in the home that is not often used, such as a basement or laundry room. There are special types of litter to cover or lessen the odor. They contain baking soda and/or odorized crystals. If kept in room with an intake vent, an air freshener may be added on the furnace filter to isolate the odor from the rest of the house.

Clumping litterEdit

Microscopic close-up of clumping cat litter, showing the fossilized remains of diatoms

Litter clumps were first developed in the UK in the 1950s by the Fuller's Earth Union (FEU), later to become a part of Laporte Industries Ltd. The type of clumping litter developed by the FEU was calcium bentonite,[citation needed] a less swelling and less sticky type than American bentonite. Subsequently in America, clumping bentonite was developed in 1984 by biochemist Thomas Nelson.[3] Most are made from granulated bentonite clay which clumps together when wet and forms a solid mass separate from the other litter in the box. This solid clumped material can be scooped out and disposed of without changing the entire contents of the litter box.

Clumping litter usually also contains quartz or diatomaceous earth (sometimes called diatomaceous silica, which causes it to be mistakenly confused with silica gel litter). Because of the clumping effect, the manufacturers usually instruct not to flush clumping litters down the toilet, because it could clog it.[4]

Clumping clay cat litters are natural products. Nevertheless, they may also contain naturally occurring crystalline silica, or silica dust, which in California is treated as a known carcinogen under Proposition 65.[5] Clay litter is also criticized by the more expensive manufacturers of non-clay litter as being commonly produced in a strip mine in an environmentally degrading process.[citation needed]

This sort of litter can be toxic to ferrets, leading to both respiratory and digestive problems.[6]

Biodegradable litterEdit

Biodegradable litters are made from various plant resources, including pine wood pellets, recycled newspaper, clumping sawdust, Brazilian cassava, corn, wheat, walnuts, barley, soy pulp[7] and dried orange peel.

Each year, more than two million tons of cat litter, or approximately 100,000 truckloads, ends up in landfills in the U.S. alone. Primarily this is not biodegradable or renewable and adds to the waste burden.[8] Some pet owners prefer biodegradable litters due to its friendliness to the environment. Biodegradable cat litter can also be eliminated completely by safely composting the used litter at home. Other cat owners can be attracted to the biodegradable litters because of their flushability or deodorizing properties.[9] Asthmatic cats may sometimes benefit from the reduced dust in some forms of biodegradable litter.

Biodegradable litter packaged specifically for cats tends to be more expensive than traditional clay litters, so cost is often not a positive factor in their selection, however, one of these, namely pine pellets can be purchased from regional feed stores that normally carry 40 lb (18 kg) bags for horse bedding at a significant cost reduction, often cheaper than the cheapest clumping litter. Most biodegradable litters last longer than the equivalent size of clay or clumping clay litters.[citation needed] Grain-based animal or poultry feed also provides an economical alternative to products marketed specifically as cat litter.[10] Also, most of these forms of litter are recycled from human usage and are thus reusing a waste product as opposed to drawing clay from mines.

Silica gel litterEdit

Silica "crystal" litter

Silica gel litter, often referred to as "crystal litter", is a porous granular form of silicon dioxide, has the highest absorbency of any litter, and has excellent moisture control and complete odor elimination for an extended period of time compared to other litters.

Some[who?] praise its absorbency because 4–5 pounds (1.8–2.3 kg) can absorb liquid and odor for up to 30 days for one healthy normal weight cat.[citation needed] It is important to lightly stir the crystals daily while scooping the solid waste, otherwise urine can pool in the box. When crystal litter is saturated, at the end of 30 days or so, it begins to smell and is visibly saturated (the white crystals have turned slightly yellow). In comparison, over the same time period it may take 20–30 lb (9.1–13.6 kg)[citation needed][11] or more of clay or clumping litter, because it is necessary to replenish the litter that is removed when the clumped urine is scooped out. No replenishing is necessary with silica gel (crystal) litter.

PrettyLitter is a proprietary silica gel litter with health diagnostic features. Its litter changes color as a reaction to a cat's urine to indicate potential health issues. The litter turns blue in the presence of high alkaline urine (potentially an indication of a urinary tract infection), yellow for high acidic urine (potentially indicating metabolic acidosis or kidney tubular acidosis), or red in the presence of blood in the urine (which might indicate bladder inflammation, bladder stones, or a urinary tract infection).[12]


Today many different litter solutions exist ranging in price from a few dollars to more than one hundred dollars. Inexpensive models may simply be an open rectangular pan with a scoop, while more elaborate models may be covered, looking similar to pet carrying cages with open doorways, providing some allegedly desired privacy to the pet, keeping the litter out of sight, and possibly reducing litter tracking. To facilitate emptying and cleaning a litter box, liners may be used. Some have a handle so they can be moved easily. Some models incorporate a motor and combing device to automatically remove excrement from the litter. Other models are hidden inside household furniture, such as side tables to blend into the home.

Open litter pansEdit

An open litter pan is generally the most basic and least expensive design. They are commonly constructed out of plastic, however some disposable models exist, in the shape of a rectangular tray with outwardly sloped sides 3.9 to 5.9 inches (10 to 15 centimeters) high. Open litter pans allow for maximum ventilation which may increase cat comfort. Also, they show the waste most visibly which may encourage owners to scoop the box more frequently. Litter pans with low walls may not contain litter when a pet scratches or digs, and some animals who eliminate standing up may be able to urinate or defecate over the walls. Some designs include a detachable rim to help catch litter when the animal kicks to bury their waste.

Hooded litter boxesEdit

An enclosed litter box

A variety of covered litter boxes exist that are commonly available and moderately priced. Many are constructed out of plastic and feature a plastic hood or dome that covers the litter pan and litter. The pet enters through an opening in the cover. Pet owners lift the cover off the tray to scoop, clean and change the litter. Covered litter boxes may reduce the amount of litter that is tracked outside the box and may address issues of pets eliminating waste over the walls of a litter pan.

Top-entry litter boxesEdit

Top entry litter boxes have an opening on the top of the box and require the pet to climb on top of the box and into a hole to eliminate waste. While cats in good physical health, even kittens, have no problems accessing these boxes, they are generally not recommended for elderly or obese cats. Top-entry designs have the added benefit of deterring other pets or young children from the contents of the litter box. Some designs feature a grate on top which allows litter from a cat's paws to fall back into the box, reducing litter tracking.

Self-cleaning litter boxesEdit

A cat using an automated fully-plumbed self cleaning litterbox with reusable plastic granules, which has a cleaning cycle that includes: automated scooping, waste flushing to laundry drain, cold water granule wash, deodorization, followed by a heated drying of the litter granules.

Self-cleaning litter boxes employ technology that automates the litter box emptying procedure. Some models have electric combing mechanisms that automatically scoop the clumps out of the litter box into a sealed, disposable-bag-lined container after the animal has used it. These models use a pressure pad or an infrared light to determine when the cat has left the box and will comb the box after so many minutes have passed, to avoid disturbing the cat. Other designs take this further, and connect directly to a home's plumbing (faucet connection and drain) so they can wash, rinse and dry the permanent litter pellets automatically. Simpler designs exist as well; for example, some require the owner to manually shake the clumps into an easy-to-remove tray. Another variant has an enclosed sphere which rotates as it sifts out the clumps and deposits them in a drawer below the sphere. A new method involves incorporating sifting functionality within a sifting litter liner.[13] Some automated litterboxes incorporate the use of a two-belt system. The top belt has litter ready to use while the lower belt has a batch of litter ready "on hold" for when the cleaning process takes place. As the litter on the bottom belt is moved up to the top, is it evenly distributed across the width of the top belt.[14]

See alsoEdit


  1. ^ "Tufts University- Outdoor vs Indoor Cats".
  2. ^ Gross, Daniel (2 February 2015). "How Kitty Litter went from happy accident to $2 billion industry". The Washington Post. Retrieved 18 July 2017.
  3. ^ "Soaking Up the History of Cat Litter". Retrieved 4 November 2016.
  4. ^ "Cat Litter – To Scoop or Not to Scoop: The Clumping Clay Controversy". Retrieved 30 April 2015.
  5. ^ "1999 Prop 65 Regulatory Update". Retrieved 30 November 2008.
  6. ^ American Ferret Association. "Choosing litter for your ferret" (PDF).
  7. ^ "Cat Litter - Toiletry Goods Litter - Cat supplies - Pet Food & Supplies - Okara - 60items | Rakuten Global Market".
  8. ^ Judd Alexander, In Defense of Garbage, Praeger 1993.[full citation needed]
  9. ^ Hall, Dave (23 September 2006). "Tackling the carbon pawprint". The Guardian. London. Retrieved 30 November 2008.
  10. ^ "Cat litter box". Retrieved 3 July 2019.
  11. ^ Anne, Melodie. "Liquid Absorbing Properties of Cat Litter". Retrieved 2 August 2019.
  12. ^ Balas, Monique. "Health-monitoring cat litter can help detect common feline illnesses". Retrieved 11 June 2018.
  13. ^ "Updated list of different types of self cleaning litter boxes". Retrieved 2 March 2013.
  14. ^ "2-belt system". Retrieved 24 June 2018.

External linksEdit