Bt products are environmentally safe. In fact, the insecticidal Cry proteins expressed in Bt corn are also produced naturally in the environment by Bacillus thuringiensis, a bacterium found in soils throughout the world. These Cry proteins and their breakdown components are non-toxic to vertebrates, including humans.
Bt products also limit the need to use synthetic insecticides, thereby reducing environmental and human health concerns. Organic growers and foresters have used the Cry 1Ab protein as a natural foliar insecticide since the 1930s. Transgenic Bt products available today provide a built-in delivery system, as the proteins are expressed directly in the plant tissue and are protected from environmental factors that can influence the effectiveness of typical foliar insecticide applications.