Not according to this article.
To date the industry has always argued that if these toxins were eaten by animals or humans they would be destroyed in the gut and pass out of the body, thus causing no harm.
Whether there are harmful levels, and a contention that the toxins are destroyed in the gut are two different arguments.
And here is the real argument, whether or not there should be mandatory labeling of GM food products. Of course, companies using and selling GM foods oppose such labeling. Consumer groups favor it, and people who want to know what is in the food they are eating also favor it, but our bought and paid for Congress has not yet enacted laws requiring labeling of GM foods. And there are other labeling laws other industries oppose successfully.
http://www.ext.colostate.edu/pubs/foodnut/09371.html