Whole Foods Market Inc. (NASDAQ:WFM) has announced it will label all products containing genetically modified organisms, or GMOs, carried in its U.S. and Canadian stores by 2018.

Walter Robb, Whole Foods’ co-CEO, made the announcement alongside A.C. Gallo, the company's chief operating officer and president, during the Natural Products Expo West show in Anaheim, Calif., last month.

“We’re setting this bold deadline -- putting this stake in the ground, because the prevalence of GMOs in the food supply, as well as the lack of mandatory labeling, makes it increasingly difficult for retailers to source and sell and offer non-GMO products, and increasingly difficult for the consumer to find those choices,” Robb said at the show.

Concern over the consumption of GMOs has been a hot-button issue lately, particularly after the passing of the so-called Monsanto Protection Act, a provision of a six-month spending measure enacted March 26, which temporarily allows the agricultural-chemicals giant Monsanto Co. (NYSE:MON) to continue selling its GMO seeds in the U.S. even if they prove to cause health problems.

With its voluntary GMO labeling plan, Whole Foods said it hopes to draw attention to the fact that there are no laws in the U.S. or Canada that require such measures and that it aims to support such efforts at the federal and state levels.

Whole Foods said that the five-year time frame was necessary to give its suppliers time to adjust and that it would be working with them throughout the transition.

The supermarket chain added that while it is currently unable to verify whether or not every product it carries contains GMOs, it does offer some 3,300 non-GMO products that have been verified through the Non-GMO Project, a nonprofit organization that tests food products for GMOs.

The Non-GMO Project has questioned many of the food-safety claims made by GMO producers based on a “GMO Myths and Truths” report produced last June by Earth Open Source, a nonprofit research group that opposes the use of pesticides, artificial fertilizers and GMOs in agriculture.

“Based on the evidence presented in this report, there is no need to take risks with GM crops when effective, readily available, and sustainable solutions to the problems that GM technology is claimed to address already exist,” the report concluded in its executive summary.