Now food companies await implementation proposals and guidelines.
The federal law will preempt any state GMO labeling laws, such as the Vermont statute that had gone into effect July 1.
The measure allows companies and producers to use QR codes, 1-800 numbers, or a text label for food products that contain GMOs.
The law requires USDA to study any potential problems consumers face with the scan code within a year after use begins.
USDA, rather than the Food and Drug Administration (FDA), will develop the implementing regulations. The standards will not go into effect for up to three years,
A likely point of contention will be making a distinction between foods with GMOs and those made with GMOs during processing but that contain nearly no trace of them in the final product.
There already are turf battles building between USDA and FDA regarding the new law. FDA said the bill's narrow and ambiguous definition of "bioengineering," would "likely mean that many foods from GE sources will not be subject to this bill" and that it "may be difficult" for any GMO food to qualify for labeling under the bill.
The label requirement will not include food products created with CRISPR, a more precise gene-editing technology.
Foods coming from livestock like beef, milk, pork, poultry or eggs do not require a GMO label, even if the animal ate feed containing GM corn or soybeans.
The law says food products receiving these labels must contain "genetic material." According to FDA, that would seem to exempt products like oils, starches, and purified proteins even if they were sourced from GE crops.
The law also says that an item is only to be labeled as genetically modified if the modification could not have occurred through "conventional breeding." The FDA raised concerns that the lack of specificity in the language could open this term up to an overly generous reading.