Aflatoxin concern with chick feed litter?

Donna sends the following:

Just as an FYI about using chicken feed as cat litter.....I'm sure there's a lot of discussion about the "real" risks involved, but below is a section from a Petfinder Forum post at http://forums.petfinder.com/viewtopic.php?t=148000:

I posted about the use of corn feed about a month ago. We used it for about 2 months with no problems. Then all of a sudden all our cats started getting sick, one by one. We checked everything. While researching some things and talking to our vet, it dawned on us what could be wrong. Our corn litter. We bought a black light and tested the litter. Nothing. The next night we tested again and there it was, aflatoxin. The conditions were perfect, warm pee and untreated corn feed. Once we got rid of the corn feed and disenfected the pans and the surrounding areas the cats are now much better. Cheap litter for sure but it really wasn't worth a $2,000 vet bill. It's actually not almost the same thing. Regular chick feed untreated. World's Best Kitty Litter is corn feed that has been treated and sanitized in order for aflatoxins not to grow.

I've seen other reports about such problems, kind of like this one at http://www.litterbox-central.com/litter-box/smartscoop/topic2618.html:

Chicken feed tends to grow mold that contains aflatoxin, which causes liver damage in cats. If the mold is present or grows in the liter, your cat will ingest it after walking in the litter and cleaning her legs/paws. I know someone on another forum who tried this and all 3 of her cats ended up in the hospital with serious live disease, and they will never fully recover.

Well, poop and piddle, something always has to rain on my parade. But that's why we blog, isn't it, to get input from a community? So I went off to do some additional web research and found that "Aflatoxins are produced under certain conditions, which include temperatures from 55--104 °F (optimum 81--86 °F), and 17--18 percent and higher moisture content."

So conceivably, using this litter in my foyer cat box room (currently 35 degrees F, brrrrr...) during the winter would likely be safe, but in the summer when its 75 and very humid probably wouldn't be such a hot idea.

I'll need to go stick a thermometer in the cat facility cat boxes. I'm guess in the winter they also are pretty chilly, since they sit on the floor. And it is dry, dry, dry up there now--I even have humidifiers going to reduce the static shock in kitty fur.

Aflatoxin is definitely a concern. Certain levels are permitted in feed.

What is aflatoxin?
Aflatoxin is a mold (Aspergillus flavus) found in corn and cottonseed (but also peanuts, sorghum,soybeans and rice) that is carcinogenic. It is caused by moisture and temperature conditions both in thefield or storage, usually greater than 70 F. Toxic response depends on species, amount consumed, level of aflatoxin, age, sex, nutritional status and physiological state. The liver is the principal organ affected.(Merck Veterinary Manual, 8th Ed.)

What are the allowable levels in animal feeds?
Feeds with greater than 20 ppb aflatoxin are not allowed for dairy animals and are not recommended for young animals. Aflatoxin levels up to 100 ppb are permissible for adult animals and up to 50 ppb for wildlife. Aflatoxin levels up 200 ppb are suitable for finishing swine and up to 300 ppb for finishing steers.

The things we learn as we blog...