Search for silica and you land on serious health warnings. Those warnings are about a different material from the beads in a crystal litter box. One is quartz dust off a building site. The other is silica gel, the sachet in a shoebox. Getting the two mixed up is the whole reason this question keeps coming up.
OSHA covers respirable crystalline silica and nothing else: particles at least 100 times smaller than ordinary sand, released by cutting, sawing, grinding, drilling and crushing stone, concrete, brick and mortar. Its page does not discuss household products at all.
The split is not a marketing idea. CDC ATSDR, a federal public health agency, divides silica into two main groups, crystalline and amorphous, and says the most common crystalline type is quartz while amorphous forms turn up in food additives, toothpaste and cosmetics. On the amorphous form it says there are no known health effects at the levels found in the environment or in those commercial products, and that lab-animal work puts it below crystalline silica for harm. It says nothing about cat litter, so neither do we.
OSHA names silica gel as a synonym for amorphous silica and lists a separate carcinogenic classification for it: IARC-3, the lowest category, meaning it is not classifiable as carcinogenic to humans. That is an independent federal listing, not a brand's own claim about its own formula, and it lines up with what the ATSDR page above already says about amorphous silica.
We weigh airborne particulate during a standard pour for every litter we buy. PrettyLitter has not been through that test yet, so its dust figure on this site reads not measured, and we will not put a number on it until it has.
If you want a low-dust litter backed by a reading rather than a category assumption today, Ökocat Paper Pellet is the lowest we have recorded at 0.00mg per pour.
The warnings people find when they search for silica are about respirable crystalline silica, which OSHA describes as a workplace hazard from cutting and grinding stone and concrete. Crystal litter is sold as silica gel, which OSHA lists as a synonym for amorphous silica. Those are different materials.
We have not weighed it. PrettyLitter is the crystal litter in our catalog and its dust figure reads not measured, so we make no dust claim about it anywhere on this site.
Ask a vet, not a review site. Silica gel beads are not food, they absorb moisture, and a cat that eats litter of any kind is worth a phone call to the practice.
Beads are large enough to be mouthed by a curious kitten, which is the reason many households wait until a cat is older. It is a question for the vet who sees your kitten.
Activated carbon you add to the litter you already buy. We have used it in our own homes for years, and with dozens of friends and family. You can keep your existing base litter.
Read our Purrify guide to picking a litter for odor control.
This page separates two materials that share a name. Where a figure is missing we say so rather than estimating, and the brand claim about amorphous silica is labelled as a brand claim.