I can't seem to find anything consistent with people and cats being able to breathe. All of them advertize that they are 99% dust-free. Search any of their reviews on the Internet and you will find that these claims are, uh, inconsistent with user experience. I'm using a cedar, pine and something else (basically sawdust) type at the moment. I may be allergic and the cats don't seem to like it either. It clumped in the past, but it isn't clumping at all now. Before, I used clay and that was even worse. It totally coated my bathroom floor and moldings, and Amelia's eye weeped and ran constantly.
I feel like buying plain sandbags. I'm fairly fed up. I looked up sand and fuller's earth, which should work, and found that that was the original Kitty Litter brand. Apparently this brand became Tidy Cats. Whether they still sell anything with fuller's earth, I can't find out for sure, but I tend to doubt it. Interesting though. I knew I should have trained Amelia to use the toilet!