Biodegradable shot cups for 12 gauge?

Okay, recently I've gotten into reloading my own 12 gauge shells. Since I'm shooting on my own property, I'm being very careful about what I use, since I don't want to leave garbage or toxins laying around. Steel shot exclusively for the shotgun, and my targets are mostly clay pigeons. However, the shot cups are still a problem. I don't want to go back to something like paper or felt wads, which are a big step down from shot cups, and I'm not sure my reloading press could handle them anyway. But I'd like something that's biodegradable. Does anyone know if there is such a thing for 12 gauge? I'm imagining a typical shot cup/buffer, but maybe made out of cardboard instead of plastic.

I shoot skeet on my land and worry about the pigeon fragments (supposedly toxic to pigs) and the wads (plastic).

I don't reload but with there was a target load with non-toxic shot and biodegradable wads, I'd buy it.

yup

Here are two report, the first for domestic swine, the second for wild swine.

Hematologic studies in pigs fed clay pigeon targets.

Eating clay might not be healthy, but since I'm not giving it to any pigs, I'm not worried. What I worry most about is the lead shot, which is why I've switched to 100% steel. Right now, that means using BB size shot for my shells, which is less effective in a sporting clays situation, but then I'm shooting for practice, not competition. You can find 7 1/2 or 8 size steel shot online, either in ready to use shells or in bulk form for loading your own the way I do. It'll be more expensive than regular shot or shells, though. But with non-toxic shot, and the clay breaking down (eventually), my biggest remaining concern is the plastic wads.

As far as I know The White Flyer Biodegradable is the only commercially available NON-TOXIC clay pigeon.

Old-school clay pigeons are made from pitch. The toxic materials in clay pigeons are coal tar derivatives, such as cresols and phenols, which are protoplasmic poisons.

Poisoning of domestic swine by ingestion of clay targets is identified by severe hemorrhagic necrosis of the liver. Roofing tar and tar paper also have the same toxic ingredients and can cause the same toxicosis.

Poisonings of this type have been associated with domestic hogs in confinement or on pastures, but we are not aware of any cases diagnosed in wild swine. Use of clay pigeons on skeet and trap ranges has never been linked with problems in wildlife.

The distinctive liver lesions associated with clay pigeon toxicosis are readily recognized upon examination. The lack of reported cases in wildlife is evidence that if clay pigeon poisoning occurs, it is extremely rare.

It's a photo-degradable fiber shot cup, apparently. Problem is, they only seem to use them to manufacture their own shells, and not sell the wads as separate components (http://www.gamebore.com/page.php?id1=2&id2=5)

There's a British company called EcoWad (http://www.ecowad.com/Home.html) that's developed the material, but it doesn't actually make wads; its purpose is to sell the material to components manufacturers, who in turn use it to make wads. Nobody appears ot have takne them up on it yet.

And you could look into PolyWad's "GreenLite" series of shells (http://www.polywad.com/greenlite.html), though, like KentGamebore, they don't seem to sell the components separately. ETA: and they only do 20 and 28 gauge.