When ‘No GMO’ Labels Fail: What Testing of Corn Chips Revealed and How Non-GMO Claims Are Verified

In 2014, Consumer Reports bought more than 80 processed foods made with corn or soy from stores in the New York City and Seattle areas and sent them to an independent laboratory to test for genetically engineered ingredients. Most of the results were unremarkable. But one product stood out: a brand of tortilla chips sold in natural food stores with “No GMO” printed on the bag. Every one of the six bags tested contained a high proportion of genetically engineered corn.

The case led to a Federal Trade Commission investigation and remains one of the clearest documented examples of a non-GMO claim that did not hold up. More than a decade later, the lessons it offers about how food labels are verified, and when they are not, still apply to shoppers trying to make sense of the growing number of claims on grocery packaging.

What Consumer Reports Tested and Found

Consumer Reports purchased the products between April and July 2014, testing at least two samples of each product from different production lots. The foods included cereals, corn chips, snack bars, soy-based infant formulas, and other items made from the two most widely planted genetically engineered crops in the United States. The published results table sorted products by the claims on their packages.

The findings fell into clear groups. Products certified organic or verified by the Non-GMO Project met Consumer Reports’ standard for non-GMO. Products that made no claim about genetic engineering, including many major snack brands, almost all contained substantial amounts of GE corn or soy, which was expected given how dominant GE varieties were in U.S. agriculture.

The “natural” label was the most revealing. A Consumer Reports survey of 1,000 people found that more than 60 percent believed “natural” meant a product contained no GMOs. But virtually all the tested products that said “natural” without an organic or non-GMO claim contained a high percentage of GE ingredients. “Natural” had no legal definition relating to genetic engineering, and it still does not.

Products carrying unverified manufacturer claims such as “non-GMO” or “no GMO” mostly tested as accurate. The exception was Xochitl Totopos de Maiz corn chips. They were labeled “No GMO” but contained a high proportion of GE corn in all six samples tested. The company’s organic white corn chips, by contrast, met the non-GMO standard. A company spokesperson told Consumer Reports that the company and its supplier were “baffled” by the results.

The FTC Investigation

In October 2014, Consumer Reports asked the Federal Trade Commission to investigate. The FTC’s Division of Advertising Practices examined whether Xochitl’s “No GMO” claim for its non-organic corn chips, used from at least 2009 through 2014, was false or unsubstantiated. The FTC staff’s closing letter, dated July 10, 2015, is unusually detailed and worth reading for anyone interested in how label claims are evaluated.

According to the letter, the laboratory results showed on average more than 75 percent GE corn content across the six packages. The FTC staff reviewed the testing method, which compared intact GE corn DNA to all intact corn DNA to account for the DNA damage that occurs when corn is cooked into chips, and concluded the results were reliable. The method was designed so that samples with too little intact DNA would return an inconclusive result rather than a false positive.

The investigation also found that the company had not specifically requested non-GMO corn from its suppliers, nor asked for information about their testing or contamination controls, even though nearly all domestically produced corn at the time was genetically engineered. The chips were not verified by the Non-GMO Project or certified organic during that period. The FTC staff concluded that without such verification or supplier evidence, the company lacked a reasonable basis for its claim.

The FTC did not recommend enforcement action. The letter noted that the company had removed the “No GMO” claim from packaging and advertising soon after Consumer Reports contacted it, had begun requiring test results with corn deliveries, was conducting its own testing of ingredient lots, and had enrolled in the Non-GMO Project’s verification program. Because the chips have a short shelf life, the staff considered it unlikely that products with the old claim remained on shelves.

The case illustrates a point the FTC letter makes explicitly: third-party verification is not required in the United States for non-GMO claims. A company can print “non-GMO” on a package based on its own assessment. The legal requirement is that it have a reasonable basis for the claim, but no one checks that basis before the product reaches the shelf.

Why a “No GMO” Product Can Contain GMOs

It is tempting to read a case like this as deliberate deception. Sometimes that may be true. More often, contamination results from how corn is grown, stored, and moved.

Corn is wind-pollinated. Pollen from genetically engineered corn can drift into neighboring non-GE fields and fertilize their plants, producing kernels that carry GE traits. The distance pollen travels depends on wind, timing, and field layout. Buffer zones and staggered planting reduce but do not eliminate cross-pollination.

Grain handling is shared. Harvesters, trucks, grain elevators, rail cars, and processing plants handle both GE and non-GE corn. Without careful cleaning and segregation, small amounts of one mix into the other.

Seed is not always pure. Even non-GE seed lots can contain a low percentage of GE seed due to cross-pollination in seed production fields.

Supply chains are long. A snack manufacturer typically buys masa flour or corn from a miller, who buys from grain handlers, who buy from many farms. Each link is an opportunity for mixing, and each depends on the documentation of the one before it.

Keeping GE content low requires a system called identity preservation: dedicated or thoroughly cleaned equipment, segregated storage, documentation at each step, and testing at key points. That system costs money, which is part of why non-GMO and organic ingredients carry a price premium. A company that simply buys ordinary commodity corn and labels the result “non-GMO” skips those costs, and in a market where roughly nine out of ten corn acres are genetically engineered, the result is predictable.

How GMO Testing Works

Testing for genetically engineered ingredients is more complicated than it sounds, especially for processed foods like chips.

PCR testing. The standard laboratory method is polymerase chain reaction (PCR), which detects specific DNA sequences associated with genetic engineering, such as common promoter sequences or the genes for particular traits. Quantitative real-time PCR can estimate what percentage of the DNA in a sample comes from GE varieties. It is highly sensitive and can detect GE content well below 1 percent in raw grain.

The processing problem. Heat, pressure, and chemical treatment break DNA into fragments. Tortilla chips are made from corn that has been nixtamalized (cooked in an alkaline solution of lime and water), ground into masa, formed, and fried. Each step degrades DNA. In highly refined ingredients such as corn syrup, corn oil, and cornstarch, so little intact DNA may remain that testing cannot determine the source at all. That is why the laboratory used by Consumer Reports compared intact GE DNA to total intact corn DNA, and why the FTC staff noted the method would produce inconclusive results rather than false positives when DNA was too degraded.

Protein strip tests. Lateral flow strip tests detect the proteins produced by GE traits, such as the insecticidal Bt proteins or the enzyme that confers herbicide tolerance. They are fast and inexpensive, and are widely used at grain elevators to screen incoming loads, but they work best on raw grain because processing destroys or alters proteins.

Process verification. Because testing finished products is difficult, credible non-GMO programs rely mostly on testing ingredients at high-risk points, typically raw grain and seed, and then documenting how those ingredients are kept separate as they move through the supply chain. Testing the final chip, as Consumer Reports did, is a check on that system rather than a substitute for it.

The Labels You’ll See in 2026

American shoppers now encounter at least five types of claims or disclosures related to genetic engineering. They mean different things and are backed by very different levels of verification.

Label	Who sets the rules	Independent verification?	What it means about GE content
USDA Organic	USDA National Organic Program	Yes, accredited certifiers; annual inspection	GE methods prohibited; process-based, with residue testing of some samples
Non-GMO Project Verified	Non-GMO Project (nonprofit)	Yes, third-party technical administrators	Testing of high-risk ingredients; 0.9% action threshold; supply chain review
“Non-GMO” / “No GMO” (unverified)	Manufacturer	No	Company must have a reasonable basis under FTC law; no standard definition
“Bioengineered” disclosure	USDA AMS (BE Disclosure Standard)	Recordkeeping; audits on complaint	Required when detectable modified genetic material is present above 5% (inadvertent); highly refined ingredients often exempt
“Natural”	No binding definition	No	Says nothing reliable about GE content

USDA Organic

Organic certification prohibits the use of genetic engineering as an “excluded method.” Certified operations must show that they do not plant GE seed, do not use GE ingredients, and take reasonable steps to prevent contact with GE material. Certifiers inspect operations at least annually and test a portion of products for prohibited substances. The organic standard is process-based: it focuses on how food is produced rather than setting a numeric GE threshold, so trace contamination from pollen drift does not automatically cause an operation to lose certification if it followed the rules.

Non-GMO Project Verified

The Non-GMO Project, a nonprofit founded in 2007, runs the most widely used third-party non-GMO verification program in North America, recognizable by its butterfly logo. Its standard classifies ingredients by risk. High-risk crops, such as corn, soy, canola, sugar beets, and cotton, must be tested, and the program uses an action threshold of 0.9 percent GE content, the same number used in EU labeling law. The FTC letter cited this threshold when describing the program. Products must also go through a review of their supply chain and segregation practices.

Unverified “Non-GMO” claims

A company can put “non-GMO” on its label on its own authority. The FTC Act requires that advertising claims be truthful and substantiated, and the FDA has issued guidance on voluntary labeling indicating whether foods have or have not been derived from genetically engineered plants. But there is no pre-approval, no standard threshold, and no routine inspection. The Consumer Reports data suggest most such claims were accurate in 2014, but the Xochitl case shows what can happen when they are not.

The federal “bioengineered” disclosure

Since January 2022, food manufacturers have been required to comply with the National Bioengineered Food Disclosure Standard, administered by USDA’s Agricultural Marketing Service. Foods containing detectable modified genetic material must be disclosed as “bioengineered” through on-package text, a symbol, a QR code, or a text-message option. The standard allows up to 5 percent inadvertent presence of bioengineered material per ingredient without triggering disclosure, and ingredients that are so highly refined that modified DNA cannot be detected, such as many oils and sugars, generally do not require disclosure. The standard has been criticized by consumer groups for the QR code option and for the refined-ingredient exemption, and it was the subject of litigation in Natural Grocers v. Rollins in the Ninth Circuit.

The BE disclosure answers a different question than non-GMO labels. It tells you when a product must disclose that it contains bioengineered food above a threshold. It does not tell you that a product without the disclosure is free of GE-derived ingredients.

“Natural”

The FDA has never adopted a binding definition of “natural” for food labels. Its longstanding informal policy says only that nothing artificial or synthetic has been added that would not normally be expected in the food. That policy does not address genetic engineering, pesticide use, or processing methods. As the 2014 testing showed, “natural” is not a reliable indicator of anything related to GMOs.

How Other Countries Draw the Line

Labeling thresholds for genetically engineered content vary widely around the world, which is one reason “non-GMO” can mean different things in different markets. The European Union requires labeling of foods containing more than 0.9 percent authorized GE material per ingredient, provided the presence is adventitious or technically unavoidable. Australia and New Zealand use a 1 percent threshold. South Korea uses 3 percent. Japan and the United States set their mandatory disclosure thresholds at 5 percent. Japan also tightened its rules in April 2023 so that a “non-GMO” claim may be used only when GE material is not detected; products that are segregated but still contain trace amounts must use different wording.

The Mexico Connection: Corn, Tortillas, and a Trade Fight

Tortilla chips carry an extra layer of meaning because corn itself carries one. Mexico is the birthplace of maize, domesticated from a wild grass called teosinte roughly 9,000 years ago, and it remains home to dozens of native corn landraces grown by small farmers. Many Mexicans view protecting those varieties from cross-pollination with GE corn as a matter of cultural heritage and food sovereignty.

That view has become national policy. Mexico had long prohibited commercial planting of GE corn, and in 2020 and 2023 its government issued decrees that restricted GE corn in tortillas and dough and signaled a phase-out of GE corn imports for human consumption. The United States, which sells Mexico roughly $5 billion worth of corn each year, most of it genetically engineered and destined for animal feed, challenged the measures under the U.S.-Mexico-Canada Agreement.

In December 2024, a USMCA dispute panel ruled that Mexico’s restrictions were not based on scientific risk assessment and violated the trade agreement. Mexico repealed its import restrictions on GE corn for human, livestock, and industrial use. But the government of President Claudia Sheinbaum then pursued a constitutional amendment. In early 2025, Mexico’s Congress approved a reform banning the planting of GE corn in the country and declaring native corn an element of national identity. The lower house passed it 409 to 69. The amendment allows imports to continue but requires that other uses of GE corn be evaluated for risks to biosafety, health, and Mexico’s biocultural heritage.

For American consumers, the practical effect is limited: tortilla chips sold in the United States are overwhelmingly made from U.S.-grown corn. But the dispute underscores that the question of genetically engineered corn is not only about individual food choice; it is also about agricultural systems, trade, and who decides what grows where.

What the Science Says About Safety

A fair account of non-GMO labeling has to include what major scientific reviews have concluded about eating GE foods. The most comprehensive U.S. review, published by the National Academies of Sciences, Engineering, and Medicine in 2016, examined hundreds of studies and found no substantiated evidence that foods from GE crops were less safe to eat than foods from conventionally bred crops. The committee also noted that its conclusions applied to the crops then on the market, and that new traits should be assessed individually.

That conclusion does not settle every concern people have about genetic engineering. Many shoppers who choose non-GMO products are not primarily worried about the DNA itself. Their reasons include:

Herbicide use. Most GE corn and soy are engineered to tolerate herbicides such as glyphosate or glufosinate, which has allowed farmers to spray them directly over crops. Some consumers choose non-GMO products to reduce potential exposure to those herbicide residues, although non-GMO conventional crops can also be treated with herbicides, just in different ways.

Farming systems. Herbicide-tolerant crops contributed to the spread of herbicide-resistant weeds, and insect-resistant traits have faced growing insect resistance. Some consumers see non-GMO or organic purchasing as support for different agricultural approaches.

Corporate concentration. A handful of companies control most of the global commercial seed market, and GE seeds are patented. For some buyers, avoiding GE ingredients is a statement about market power rather than food safety.

The right to know. Many people simply want accurate information about how their food is produced, regardless of safety conclusions. That was the central argument behind state labeling campaigns in the 2010s.

Whatever the motivation, a label is only useful if it is accurate. The Xochitl case matters not because of what it reveals about GE corn, but because of what it reveals about label claims that no one is required to check.

Timeline: GE Food Labeling in the United States

The rules governing GE-related claims developed piecemeal over three decades, which helps explain why the current system mixes mandatory disclosure, voluntary claims, and private certification.

Year	Development
1992	FDA policy statement treats most foods from new plant varieties, including GE plants, like their conventional counterparts; no special labeling required.
1996	First large-scale commercial plantings of GE corn and soybeans in the U.S.
2000–2002	USDA National Organic Program standards take effect, prohibiting genetic engineering in certified organic food.
2007	Non-GMO Project founded; third-party verification program launches soon after.
2014	Consumer Reports tests 80+ corn and soy products; asks FTC to investigate a “No GMO” chip claim.
2015	FTC closes Xochitl investigation (July). FDA issues final guidance on voluntary labeling of foods derived or not derived from GE plants (November).
2016	Vermont’s mandatory GE labeling law takes effect (July 1); Congress passes national bioengineered disclosure law weeks later, preempting state laws.
2018	USDA publishes the final National Bioengineered Food Disclosure Standard.
2022	Mandatory compliance with BE disclosure begins January 1.
2024–2025	USMCA panel rules against Mexico’s GE corn restrictions; Mexico enacts constitutional ban on planting GE corn. BE standard challenged in the Ninth Circuit.

Two features of this history stand out. First, the federal government has never required independent verification of voluntary non-GMO claims; it has left that role to private certifiers and, after the fact, to the FTC and consumer lawsuits. Second, the mandatory disclosure that does exist was designed with a relatively high threshold and broad exemptions, reflecting a compromise between labeling advocates and the food industry. Both features mean that consumers who care about GE content have to do some of the verification work themselves by recognizing which labels carry real assurance.

What Changed After 2014

The years around the Consumer Reports testing were a turning point for non-GMO labeling in the United States. In 2014, General Mills announced that original Cheerios would be made without GE ingredients, one of the first major mainstream brands to make the change. State ballot initiatives and legislative battles over mandatory GE labeling were at their peak, culminating in Vermont’s labeling law taking effect in July 2016, only to be preempted weeks later when Congress passed the national bioengineered disclosure law.

Third-party verification grew rapidly in the same period. Manufacturers that had relied on their own “non-GMO” statements increasingly sought Non-GMO Project verification, partly because retailers began to require it and partly because cases like Xochitl’s showed the reputational risk of an unverified claim. Xochitl itself enrolled in the program as part of its response to the FTC.

The regulatory landscape also shifted. The national BE disclosure standard became mandatory in 2022. New gene editing techniques, which can alter a plant’s own DNA without inserting genes from another species, raised new questions about what counts as “genetically engineered” for labeling purposes. Under the USDA’s BE rules, many gene-edited foods that contain no detectable foreign DNA may not require disclosure, while the Non-GMO Project treats most gene editing as a GMO technique. Shoppers can expect those definitional differences to matter more in the coming years as gene-edited crops reach the market.

What a Credible Non-GMO Claim Requires

The FTC letter effectively lists the ingredients of a claim that can be substantiated. Companies that make non-GMO claims responsibly, whether or not they pursue third-party verification, typically rely on several layers of evidence.

Specified sourcing. The company contracts specifically for non-GMO or identity-preserved grain, rather than buying commodity corn and assuming the best. Contracts spell out that GE varieties may not be used and that the grain must be segregated.

Supplier documentation. Growers and millers provide affidavits about the seed planted, along with certificates of analysis showing test results for each lot or delivery.

Incoming testing. The manufacturer tests representative samples of incoming raw ingredients with PCR or strip tests, focusing on high-risk crops.

Segregation and traceability. Non-GMO ingredients are stored and processed separately, or equipment is cleaned between runs, and lot numbers allow any batch to be traced back to its source.

Periodic finished-product checks. Although processing makes finished-product testing harder, periodic checks catch failures upstream, which is exactly what the Consumer Reports test did from the outside.

Independent verification. Enrolling in a program such as the Non-GMO Project adds an outside reviewer who confirms that the above steps are in place.

According to the FTC letter, Xochitl’s pre-2014 approach lacked most of these elements. Its post-2014 approach added nearly all of them. For consumers, the presence of a third-party seal is the easiest shortcut to knowing that a company has done this work.

A Shopper’s Guide to GE-Related Labels

For people who want to avoid genetically engineered ingredients, the evidence from testing and enforcement points to a few straightforward rules.

Trust third-party seals over self-declared claims. The USDA Organic seal and the Non-GMO Project Verified butterfly are both backed by independent verification. In Consumer Reports’ testing, both performed reliably.

Treat unverified “non-GMO” claims as generally, but not always, reliable. Most were accurate in 2014 testing. If a product matters to you and carries only a manufacturer’s claim, look for supporting information on the company’s website, such as supplier testing or a statement about identity-preserved sourcing.

Ignore “natural” for GE purposes. It carries no information about genetic engineering.

Understand what the BE disclosure does and does not tell you. A bioengineered disclosure means detectable GE material above the threshold. The absence of one does not mean the product is free of GE-derived ingredients, especially highly refined ones like oils and sugars.

Focus on high-risk ingredients. In the U.S. market, the ingredients most likely to be derived from GE crops are corn, soybeans, canola, sugar beets (the source of much “sugar” on labels), and cotton (cottonseed oil). Products without these ingredients are unlikely to contain GE material regardless of labeling. Other commercially available GE crops include certain varieties of papaya, summer squash, potatoes, apples, and alfalfa.

Buying Tortilla Chips Specifically

For tortilla chips, a few additional points apply. Chips are made from corn, the crop with the highest GE adoption in the U.S. alongside soybeans and cotton, and are fried in oil that may come from corn, soy, canola, or cottonseed. That means both the grain and the oil are potential sources of GE ingredients.

Organic tortilla chips or Non-GMO Project Verified chips address both. Chips made from blue, white, or heirloom corn are not automatically non-GMO; color alone says nothing about whether the corn was genetically engineered, though specialty and heirloom varieties are less commonly GE. Chips fried in avocado, olive, sunflower, or safflower oil avoid the major GE oil crops.

Beyond GE status, tortilla chips vary considerably in sodium, often from about 80 to more than 200 milligrams per one-ounce serving, and in the type of oil used. Checking the Nutrition Facts panel for sodium and serving size is as useful as checking for a non-GMO seal.

Frequently Asked Questions

Can a product labeled “non-GMO” contain GMOs?

Yes, especially if the claim is not independently verified. Even verified products may contain trace amounts below program thresholds, such as the 0.9 percent action threshold used by the Non-GMO Project, due to unavoidable cross-pollination or handling.

Is “organic” the same as “non-GMO”?

Organic standards prohibit genetic engineering, so certified organic products are produced without GE ingredients. But non-GMO does not mean organic; a non-GMO product can be grown with synthetic pesticides and fertilizers that organic rules prohibit.

What happened to the tortilla chip company in the Consumer Reports case?

According to the FTC’s July 2015 closing letter, the company removed its “No GMO” claim, began requiring and conducting GE testing of its corn, and enrolled in the Non-GMO Project’s verification program. The FTC staff decided not to recommend enforcement action.

Do “bioengineered” labels tell me if a product has GMOs?

They tell you when detectable modified genetic material is present above the federal threshold. They do not cover many highly refined ingredients, and the disclosure can take the form of a QR code rather than text on the package.

Are GMO foods unsafe?

The 2016 National Academies review found no substantiated evidence that GE foods then on the market were less safe to eat than conventional foods. People choose non-GMO products for a variety of reasons, including concerns about herbicide use, farming practices, corporate concentration, and personal preference.

The Bottom Line

The 2014 tortilla chip case is a small story with a large lesson: a claim on a package is only as reliable as the system behind it. In that case, a company made a specific, checkable claim without having taken the steps needed to support it, and independent testing caught the gap. The reforms that followed at that company, sourcing verification, ingredient testing, and third-party certification, are the same elements that make any label credible. For shoppers, the practical response is not to distrust every label, but to know which ones are independently verified, which are self-declared, and which, like “natural,” carry no meaning about genetic engineering at all.

References

1. Federal Trade Commission, Division of Advertising Practices. Closing letter re: Xochitl, Inc., FTC File No. 152-3012. July 10, 2015. ftc.gov
2. Consumer Reports. GMO corn and soy test results table (products purchased April–July 2014). October 2014. hagstromreport.com
3. WABC-TV. Consumer Reports: Many processed foods labeled ‘natural’ contain GMOs. October 2014. abc7ny.com
4. Common Dreams. GMOs Are Everywhere and Should Be Labeled, Study Finds. October 7, 2014. commondreams.org
5. USDA Economic Research Service. Adoption of Genetically Engineered Crops in the United States. ers.usda.gov
6. USDA Agricultural Marketing Service. National Bioengineered Food Disclosure Standard. ams.usda.gov
7. USDA Agricultural Marketing Service. National Organic Program. ams.usda.gov
8. Non-GMO Project. Product Verification. nongmoproject.org
9. National Academies of Sciences, Engineering, and Medicine. Genetically Engineered Crops: Experiences and Prospects. 2016. nap.nationalacademies.org
10. Seed World. Mexico Approves Constitutional Ban on Planting Genetically Modified Corn. March 24, 2025. seedworld.com

Last updated: September 26, 2026