Safe non toxic litter for 4 week old kittens

I've been doing some reading on non clumping cat litter and have read that it's both toxic to cats and humans. I foster for a shelter so of course clay litter is cheap so that's what I'm given to care for my fosters. I use the non clumping clay only. I emailed the company World's Greatest Cat Litter and they told me their litter is not suitable for kittens under 4 months of age. Is there a safe non toxic litter that I can use for my 4 week old fosters. I decided that I will spend the money and buy it for my kittens. Any advice? Thank you!

Interesting.  I didnt knew there was unsuitable, poisonous clay litters.  I guess they do perfume it  or something.

The normal, baked clay non clumping litters should be OK.  I havent never heard anybody complaining.   they can be dusty, but poisonous?

clumping clay litters shouldnt be poisonous they too, if not perfumed or chemically treated.  but as we know, they are by other reasons unappropriate even dangerous for young kittens.

Lets see what people tells of other brands, or have long practical experience.

I wonder, if they who answered your mail, if they perhaps misunderstood something?   And gave the answer supposed for clumping litter, also for the non clumping litters?

I have noticed in other circumstances, the clerks minding the telephone are not always the brightest persons around.  Making it quite peculiar, there is this big company making this excellent product, but having such a weaks spots :

Its not seldom people in the distribution...

I'll go to the article I read and post it. It just made me nervous to read this, not just for my kittens but for my family. So I'm hoping it's just hogwash. I know you shouldn't believe everything you read, that's why I posted it here.

So for some reason I can't copy the links, but you can read lots of info on this subject through google. Even modern cat has an article of the dangers of clay litter.

As far as The World's Best Cat Litter I did make it very clear that the kittens were 4 weeks of age. I was under the impression that all their litters were all the same except for scent. The company for sure doesn't want to be liable, so I understand. I just wish that there was a safe Kitten litter. I sent Swheat Scoop an email last night, so we'll see what they say. I would like to stop using the non clumping clay if I can.