posted 15 years ago
Yes you are fine composting it.
The genes in BT crops and in RU crops came from soil bacteria that were also fine to compost. Yes the BT crop will kill any Lepodoptera (butterflies and moths, both rare in the compost pile) or Coleoptera (beetles, somewhat more common) that happen to eat it, however much of the organic produce that would normally go into a compost pile has already been sprayed with BT or some other organic pesticide that will have a similar effect.
As for the Roundup ready stuff, firstly I'd like to point out that a Teratogen (causes developmental problems in a fetus, most common source in human life is any member of the mustard family) and a Mutagen (alters the DNA) are entirely different things, So I think the source on that information is unreliable at best. The big problem with roundup ready crops is that they are often hosed down with roundup, this is less of a problem with most of the crops that humans get because they take the shells off the soybeans and the cotton and corn out of the husks. I would recommend against composting cotton straw from a RU crop. Once the Glyphosate enters the cell the RU gene actually breaks it down, that is how it works, so the inside of the plant is roundup free, if it weren't the plant would die.
Really the "unknown risk" off of using GM crops in your compost pile versus normal or organic crops is smaller than the "unknown risk" of composting a new weed that shows up in your garden.