Editing Litter box (section)

====Clay====
[[File:Fig.1.SEM-image of cat litter.jpg|thumb|Microscopic close-up of clumping cat litter, showing the fossilized remains of [[diatom]]s]]
Litter clumps were first developed by using [[calcium bentonite]] clay. This was manufactured in the UK in the 1950s by the Fuller's Earth Union (FEU), which later became a part of Laporte Industries Ltd. Subsequently in America, clumping bentonite was developed in 1984 by biochemist Thomas Nelson.<ref>{{cite news |url= http://www.biscaynetimes.com/index.php?option=com_content&view=article&id=2147:soaking-up-the-history-of-cat-litter&catid=82:pet-talk&Itemid=247 |title=Soaking Up the History of Cat Litter |work=Biscayne Times |access-date=4 November 2016}}</ref> Most are made from granulated [[Bentonite|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.<ref name="cats">{{cite web |url= http://cats.about.com/cs/litterbox/a/clumpingclay.htm |title=Cat Litter – To Scoop or Not to Scoop: The Clumping Clay Controversy |access-date=30 April 2015}}</ref>

Clumping clay cat litters are natural products. Some may also contain naturally occurring [[crystalline silica]], or silica dust, which in California is treated as a known carcinogen under [[California Proposition 65 (1986)|Proposition 65]].<ref name="prop65">{{cite web |url= http://www.calprop65.com/99regs.html |title=1999 Prop 65 Regulatory Update |access-date=30 November 2008 |archive-url=https://archive.today/19991023135307/http://www.calprop65.com/99regs.html |archive-date=23 October 1999 |url-status=dead}}</ref> Clay litter is also criticized by the manufacturers of non-clay litter because the components of clay litter are commonly obtained from a [[strip mine]] in an environmentally degrading process.<ref>{{cite web |last=Donge |first=Lily |url=https://groundswell.org/kitty-litter-not-6-cheap-ways-to-reduce-your-pets-environmental-impact/ |title=Kitty, Litter Not! 6 Cheap Ways to Reduce Your Pet's Environmental Impact |publisher=Groundswell |date=22 October 2009 |access-date=4 April 2020}}</ref>
<ref>{{cite web |url= https://fullpaw.com/environmental-impact-of-cat-litter/ |title=The Environmental Impact of Cat Litter |website=FullPaw.com |date=20 June 2023 |access-date=20 June 2023}}</ref>

This sort of litter can be toxic to [[ferret]]s, leading to both respiratory and digestive problems.<ref>{{cite web |url= https://www.ferret.org/pdfs/education/bestlitter.pdf |title=Choosing litter for your ferret |date=2015 |work=Ferret.org |publisher=American Ferret Association}}</ref>