Since your cat’s litterbox is something he or she comes into contact with on a regular basis, it’s important to consider how safe the litter you’re using actually is. Each type of litter has its pros and cons. Clay litter contains silica, which can cause lung problems. Clumping litter can cause intestinal issues and blockages if your cat ingests it. Wheat, corn, pine, paper, or walnut shells cat litter: mostly safe, but could contain pesticides. Try to do some research to find out which litter is safest for you and your feline friend!