Genetically-engineered seeds account for more than 80% of U.S. corn, soybean and cotton plantings.

Genetically-engineered seeds continue to be popular with farmers, now accounting for more than 80% of U.S. corn, soybean and cotton plantings while spreading to many — but not all — other countries. Genetically-engineered foods and food ingredients, however, continue to face an unsettled world.

Within the United States, competing bills are lining up on the federal level in an effort to make state-by-state initiatives superfluous. Senator Barbara Boxer of California and Representative Peter DeFazio of Oregon in February introduced their Genetically Engineered Food Right-to-Know Act of 2015. The bill would require labeling of retail foods with bioengineered ingredients. As the bill’s title indicates, the principal argument is that “consumers have a right to know what is in the foods they eat.” The bill has 13 Senate and 22 House co-sponsors and is endorsed by 120 private-sector businesses or advocacy groups.

Support for a different approach

Major food companies support a different approach, represented by Representative Mike Pompeo of Kansas’ Safe and Accurate Food Labeling Act, also recently introduced. Mr. Pompeo would require pre-market notification to the U.S. Food and Drug Administration (F.D.A.) of any bioengineered organism or ingredient. The F.D.A. would have a limited time to accept or reject it as safe for people and animals. If safe, the product goes to market without labeling, except where it is “materially different” from its conventional counterpart and presents a risk to health, safety or deception of consumers. It also would require the U.S. Department of Agriculture to regulate non-G.M.O. labeling in a process modeled after the U.S.D.A.’s National Organic Program. Users of a non-G.M.O. label would be prohibited from stating “either expressly or by implication” that their goods are safer than bioengineered ones.

Within the European Union, its stringent labeling and traceability requirements for genetically-modified organisms remain in place, but new legislation recently was enacted that breaks a longstanding deadlock over approvals of bioengineered seeds for European cultivation. The new policy allows national governments to ban planting of a bioengineered variety even after it has been approved by the European Commission. The likely result will be a patchwork pattern of biotech plantings across Europe. A larger concern is that this application of the E.U.’s “subsidiarity” principle could eventually carry over to imported food and feed items.

Science versus “Rights”

The science on the safety of G.M.O.s is pretty clear. The national scientific academies that have considered the issue agree that bioengineered foods are as safe as their conventional counterparts. A recent Pew Research study found that 88% of scientists say that it is “safe to eat genetically modified foods.” This is essentially the same percentage of scientists who say that “childhood vaccines should be required” (86%) or that “climate change is mostly due to human activity” (87%). Yet, as with childhood vaccines and climate change, scientific consensus does not settle the matter.

So, the “right-to-know” argument is likely to continue to be put forward, and it bears closer inspection. Proponents of this right do not specify how many consumers demand it, or why. Both are important because the answers shape who should bear the costs of disclosure and how the right should be recognized.

The costs of disclosure center less on the labeling cost per se than on what constitutes an amount that should be disclosed. To meet a zero or near-zero threshold for disclosure would require an identity-preservation system from farm to consumer. That is very costly, and the model for “certified organic” might be the best one in such a case. This would place the costs of compliance on non-G.M.O. providers and consumers, which is where they fall under voluntary “non-G.M.O.” labeling regimes.

Since there are no safety risks requiring such a low threshold and since many — maybe most — consumers do not want to pay extra for disclosure, advocates of a right to know should consider accepting more commercially realistic thresholds. The current U.S. marketing system could likely provide consumer choice between bioengineered and non-bioengineered foods at a 10% threshold, especially if mixing and blending measures are available to meet it. This would not ensure non-exposure, but it would minimize exposure to bioengineered ingredients for those who want it. The costs would be much smaller than under identity preservation, which would reduce industry resistance to mandatory labels. It might also open the door to wider consumer acceptance of G.M.O.s over time.

Mr. Pompeo’s bill does speak to one “right to know” that likely commands general support. Most of the public probably does want to be reassured that F.D.A. safety regulators agree that a bioengineered product is safe as science defines that conclusion. Currently, providers alert the F.D.A. to new product offerings but are not required to do so, and the F.D.A. is not required to agree affirmatively that the product is safe. Mr. Pompeo’s bill would put those assurances into law.

It may be that the best way to stabilize the currently unsettled G.M.O. world is to define more precisely a “right to know” what and why. For those who want totally “non-G.M.O.” in spite of scientific consensus around biotech’s safety, they may have to shoulder the extra costs of identity preservation needed to provide such assurance. For those who want greater choice in the marketplace in a way that balances costs and concerns, a mandatory label may be possible but only with commercially realistic thresholds and remedies. And for those who merely want to know that regulatory science finds a product safe, Mr. Pompeo’s bill would do it.