Is Mineral Blue Safe?

I don't know if anyone here has ever heard of this stuff called Mineral Blue, but it's an orderless litter box additive that is supposed to help reduce the smell in the box. I've been using it & I think it does a preety good job, but I'm starting to wonder if it's OK for my cats. Basicly it's a super bright blue color & I noticed that it stains Jordan & Maggie's feet blue. I'm sure the same thing is happening to the other two it's just that they are grey & Maggie & Jordan have white feet. So I'm wondering if anyone knows anything about this stuff. I bought it from the Dr.'s Foster & Smith catalogue & thought it would be safe, but I don't like the fact that it's staining thier feet.

it is mainly menthol... I would keepo them away until talking to the vet..

OK, I went to the Dr.s F & S web site & here's a list of the ingrediants.

Ingredients: L-aspartic acid, zinc oxide, natural and synthetic zeolites, and Pigment Blue 15.

Anyone have any ideas or info? Or is there somewhere I could check if these are OK for cats?

try googling the ingrediants .... and calling the vet they have books to reference

After I thought about it I realized that I'm signed up for an on-line service with my vet's office. I don't even have to call I just send a message though the "Pet Portal" & the'll get back to me in 24 - 48 hours. I haven't added any to the boxes in a week so I'm not worried about immediate danger, but I won't use any more till I hear from them.