We oppose mandatory labeling of GM food because we believe such a label would convey to consumers that food made from farmers’ crops grown with our seeds is less safe or nutritious than or different from conventional or organic food. A 2013 study conducted by an MIT professor indicated that this indeed would be the case [see "Policy and Inference: The Case of Product Labeling"].
We support consumers' right to know about the food that they are choosing, but in the absence of any food-safety concern, and as believers in GM technology who have seen its benefits accrue to farmers and communities around the world (check out "GMOs and the Future of Agriculture"), we believe claims regarding the presence or absence of GM ingredients are best left to voluntary, market-based labels that traditionally are used by competitors to promote one type of product over another.
With regard to safety, we are not asking for you to take our word for it, but we ask you to consider the hundreds of independent studies demonstrating that GM food does not raise any new concerns about the food we eat (check out independent studies at Biofortified). In addition, scientific and regulatory authorities around the world have determined that GMOfoods on the market are as safe and nutritious as their non-GM counterparts [see FDA information here].
A few studies have asserted that such a risk exists, but each of these studies has been found not to be credible by the global scientific community. With regard to the rat studies you are referring to, stay tuned. We have experts addressing that question. Numerous independent scientists wrote letters of rebuttal and protest to the journal Food and Chemical Toxicology regarding those studies. These may be accessed at here.