[nkurz]

Wouldn't one argue that a better way to explain it would be to specify nonorganic kitty litter since that would clear up any confusion whether written or spoken?

I don't know. Spoken, "a nonorganic" doesn't strike me as clearly better than "an inorganic" at differentiating from "an organic". Perhaps if you knew in advance the qualififications of the intended recipient, but in a safety specification like this, you may not know much about who will be (mis)interpreting the directive. Specifying "an inorganic zeolite sorbent" in the context of nuclear waste may make it more likely that someone who isn't sure about the meaning of one of those terms will seek clarification. By contrast, I'd worry that specifying "nonorganic kitty litter" would increase the chances that someone will just ignore the essential qualifier.

Worse, the word "organic" is overloaded, and means different things to the general public than to chemists. Juxtaposing the chemical meaning with the vernacular "kitty litter" increases the likelihood that someone will misinterpret, especially when "nonorganic" is more commonly associated with marketing and "inorganic" with chemistry. In cases like this where a seemingly innocuous detail is actually of critical importance, it needs to be emphasis and redundancy. The oft-quoted rule of "omit needless words" is more applicable to fiction and journalism than to safety specifications. For something as crucially important as this, I probably would suggest something like "a chemically inorganic sorbent, such as a 'kitty litter' made from zeolite clay".