There is no long-term safety testing of genetically engineered food. Short-term animal feeding trials are conducted in some cases. The research is mostly done by the biotech companies themselves. No evidence from human trials for either toxicity or allergy testing is required. No independent checks of the company’s claims are required.
"Monsanto should not have to vouchsafe the safety of biotech food. Our interest is in selling as much of it as possible." Phil Angell, Director of corporate communications, Monsanto Corporation