Mexico’s attempts to rid the country of genetically modified corn from the U.S. could ultimately be put in the hands of a third-party dispute panel, and both sides are counting on science and common sense to prevail.

While there is no specific language in the U.S.-Mexico-Canada Agreement that says Mexico must allow its people to consume food made from genetically modified plants, there are provisions that prohibit a country from blocking trade without scientifically sound justification.

If the U.S. does eventually pursue a USMCA case – a process it has yet to begin by seeking technical consultations over the issue – the U.S. corn and biotech sectors are confident the Biden administration will have the winning hand.

“Unless Mexico knows something that isn’t known by scientific experts the world over, the authors of more than 1,700 studies – many of them independently funded — on the safety of ag biotechnology, and the U.S. FDA, then there is no scientific basis for the ban,” Lynne Finnerty, director of ag & environment communications for the Biotechnology Innovation Organization, told Agri-Pulse. “BIO is confident in the safety of ag biotech and so is the U.S. government, as evidenced by FDA’s Feed Your Mind campaign.”

Lynn Finnerty.jpegLynne Finnerty, BIO

And science, Agriculture Secretary Tom Vilsack says, is the foundation of his distress over Mexico’s second presidential decree that seeks to block the U.S. GM white corn from making its way into Mexican food. 

“The U.S. believes in and adheres to a science-based, rules-based trading system and remains committed to preventing disruptions to bilateral agricultural trade and economic harm to U.S. and Mexican producers,” Vilsack said. “We are carefully reviewing the details of the new decree and intend to work with USTR to ensure our science-based, rules-based commitment remains firm.”

But Mexico has the right to its own science, and the country will use it to defend its actions, says Tim Wise, a senior research fellow at Tufts University and a senior adviser for the Institute for Agriculture and Trade Policy, a Minnesota-based research and advocacy group.

“There’s plenty of science to justify precaution … on GM corn consumption,” said Wise. “It’s not up to Vilsack to determine what level of tolerance Mexico needs to accept or what constitutes sound science. USMCA doesn’t give the U.S. the right to make those determinations … It mandates that there’s transparency in decision-making and that it’s science-based – not which science.”

The Office of the U.S. Trade Representative recently demanded Mexico provide detailed scientific justification to back up its proposal to restrict the use and imports of GM corn. The Mexican response, which USTR received last week, hasn’t been made public.

While there are many scientific studies supporting the safety of genetically engineered crops, there are some studies that point the other direction, according to an analysis by Sheldon Krimsky, a professor at the School of Medicine at Tufts University, who died in April last year.

“Both skeptics and non-skeptics of GMOs purport to debunk the myths of their opponents,” he wrote.

The National Corn Growers Association is skeptical of scientific evidence Mexico is claiming to follow.

“Scientists at USDA, FDA, EPA as well as experts at USTR will be interested in seeing their scientific evidence,” says NCGA Director of Public Policy, Trade and Biotechnology Angus Kelly. “So are we.”

And as to the science backing the safety of genetically engineered corn, Kelly says: “We’re confident, but we don’t expect observers to take NCGA’s word for it. The major food safety agencies around the world have determined that, once granted approval through a long, expensive and thorough regulatory process, GM crops are safe for the people and the environment.”

But Mexico, in its latest presidential decree, is not just defending its actions on health concerns. President Andrés Manuel López Obrador also said he’s acting on a desire to save Mexico's “heritage” of domestically produced white corn, while also making sure that the country’s livestock producers have enough access to imported U.S. corn.

“This decree is historic for Mexico and for the world, since corn is the most important crop on the planet and its future depends on preserving the biocultural wealth of our country, which has its center of origin in Mexico and it was here where the millenary cultures domesticated it,” Mexico’s Ministry of Environment and Natural Resources said in a statement last week.

That goes far beyond just health concerns and would not be covered by any scientific rationale.

A ban that’s not a ban?

The first presidential decree out of Mexico threatening U.S. corn exports to the country was vague about what kind of GM corn would be affected by a ban that would go into effect in January 2024. The second decree, published on Feb. 13, made it clear that Mexico is now only insisting that the white, food-grade corn its tortilla makers use be non-GMO.

Sharon_Bomer_Lauritsen.jpgSharon Bomer Lauritsen, AgTrade Strategies

Mexico argues it is imposing no restriction on trade, because it's not banning the importation of GM white corn, only prohibiting Mexican food makers from using it.

Sharon Bomer Lauritsen, founder of AgTrade Strategies LLC and former assistant USTR for agricultural affairs and commodity policy, said Mexico's argument doesn't make sense.

Don’t miss a beat! It’s easy to sign up for a FREE month of Agri-Pulse news! For the latest on what’s happening in Washington, D.C. and around the country in agriculture, just click here.

“If the Mexican government is not going to allow the use of (genetically engineered white) corn, that clearly means that GE corn cannot be imported into Mexico for human consumption,” she said. “The (Mexican) companies are not going to import product that they cannot use.”

And then there are the Mexican livestock producers. They need U.S. feed corn because Mexico can't produce anywhere near the amount needed to support meat production in the country. Regardless of any health concerns about biotechnology, the López Obrador administration recognizes that.

The U.S. exported 15.4 million metric tons of corn to Mexico in 2022, according to USDA data. 

One reason Mexico should not import white corn from the U.S., says the Ministry of Environment, is that the country’s farmers can produce enough to make tortillas without imports.

“This does not represent any impact on trade or imports, among other reasons, because Mexico is self-sufficient in the production of white corn free of transgenics,” the ministry said. “It is a question of consolidating such sovereignty and food security in a central input in the culture of Mexicans.”

If the U.S. does use USMCA to challenge Mexico’s decree, it will be up to an independent panel to decide which country's arguments are right. 

“It’s a panel of experts that Mexico and the United States would ask to determine whether Mexico was meeting its obligations under USMCA,” says Bomer Lauritsen.

For more news, go to