The Senate this week voted to approve a bill that would require foods with genetically modified ingredients to have those ingredients labeled, Reuters reports. It will now head to the House of Representatives, where it's expected to pass as well.

Food producers can include QR codes

As our sister site Vox explains, the bill has proved controversial for several reasons, on both sides of the GMO labeling debate. The first reason is one that's been brought up in the debate over labeling in general: the science suggests GMOs are safe to eat, and any bill is unnecessary, critics argue.

But the other reason is particular to the bill just passed. The bill requires food producers to include packaging that has information on GMO ingredients, but provides different ways to make that packing. The producers can include text or a symbol identifying GMO ingredients, or can include a QR code that links out to more information on those ingredients.

That last part has been a sticking point, even among politicians that are for the labels. Some label supporters — such as Senator Bernie Sanders — have claimed that the QR codes are an unnecessary hurdle for consumers.

The longstanding controversy over GMO labels turned more pressing earlier this month, when a Vermont law mandating labels for GMO foods went into effect.