Pettex “Super Sieved” cat litter is made from pure grey fullers earth, which was formed millions of years ago in natural sedimentary deposits. This type of clay is often referred to as heavyweight or grey, and is renowned for its ability to neutralize odors without the need for chemical additives or fragrances. Every granule has a capacity to hold up to 125% its own weight in moisture and is also effective at reacting with and neutralizing ammonia. This litter absorbs liquids instantly, making it much less likely for liquids to spread and soak the whole tray. When soiled, the litter forms a solid lump, which can easily be removed with a scoop, leaving the tray with fresh, clean litter. By removing only the soiled litter, this product is incredibly economical. Pettex “Super Sieved” cat litter is also guaranteed to be harmless to both animals and humans, giving you the assurance that it can be used with complete confidence.