For the first time ever, the US will have a national standard when it comes to labeling genetically modified ingredients. President Barack Obama signed into law a bill requiring manufacturers to declare on the label if a product contains genetically modified organisms (GMOs).

The legislation—S. 764, which passed in both the House and Senate in July—compels manufacturers to disclose if a product contains genetically modified ingredients through the use of a text label, symbol or electronic code readable by a smartphone such as a QR code. The bill supersedes the Vermont GMO labeling law, which went into effect July 1 and preempts other states from passing similar legislation.

Many in the food industry were critical of the Vermont law and supported mandatory labeling at the federal level in order to avoid a patchwork of state-by-state laws. The scientific community does not share a concern over the safety of consuming GMOs. However, some consumer groups and labeling advocates argue there is not enough information available about the long-term effects of GMOs and say people have a right to know what’s in their food.

The FDA has declared GMOs are safe to eat, and a large percentage of food products already contain GMOs, many of which are corn- or soy-based. USDA will have two years to write the rules.