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Is GMO-free production possible? Costs and methods of crop segregation

(Nov. 23, 2001 -- CropChoice news) -- The following is a fact sheet about segregation of transgenic from non-transgenic crops by Neil Sorenson of the Institute for Agriculture and Trade Policy.

Organic producers, who by definition must be GMO-free are taking many precautions to keep GMOs out of their products. Cross-pollination and commingling in elevators and transport systems make identity-preservation difficult. Customer demand, especially in export markets and corporate investment in varietal traits, however, are creating incentives for segregation.

Organic growers, with their de facto ban on genetically modified organisms, have taken many precautions to ensure the maintenance of virtually pure genetic strains. Admittedly, even for organic producers, some trace amounts of genetic contamination have been found, despite stringent requirements.

Will industry, grain handlers and producers be able to develop the necessary identity preservation systems to achieve reliably GMO-free products on a large scale?


Obtaining high seed purity levels for corn is difficult because cross-pollination of a seed-producing plant by the pollen of a plant of undesirable variety is very likely. Given the rapid contamination of cornfields, most conventional seed corn producers are no longer able to guarantee 100% seed purity. Current practices significantly underestimate the size of buffer zones necessary to ensure a GMO-free grain. The only practical way to meet very high GMO-free purity standards for corn would be to create very large isolation zones in which only non-genetically modified corn is grown for miles around. Setting up and administrating such an isolation zone, and enforcing compliance by neighboring farmers who may have economic incentives to grow GM corn, would present many organizational difficulties.

New elevators are being built with future segregation and identity preservation needs in mind, but the current grain handling system would need to be significantly modified to support identity preservation practices. Companies or cooperatives that own several different elevators may be able to clean and dedicate entire elevators exclusively to non-GM grains at some expense. Trucks and barges as well as manufacturing facilities will need to be cleaned or acquired new and kept clean to handle identity-preserved stock. Along every link of the food chain, separate pathways for distinct products will need to be maintained.


Cross-pollination can be prevented or minimized by using both physical and biological isolation. Physical isolation can make use of distance, as well as natural and man-made barriers, such as valleys or tree stands. Biological isolation is much more effective than physical isolation. Simply put, if the pollination date of an organic crop can be offset by 7-10 days relative to the pollination date of genetically engineered crops grown nearby, cross-pollination can be virtually prevented.


Assuming that farm labor can be hired during planting season for $15 dollars per hour, it would cost no more than $15 to sufficiently clean out a mechanical planter between GMO and non-GMO runs. It takes approximately 40 minutes to clean out an 8-row planter and 55 minutes for a 12-row planter to obtain a non-GMO purity level of 99.9%.


During harvest season, it would take two people approximately four hours to remove virtually every kernel of grain from a combine’s inner workings. Another harvesting procedure that obtains high levels of purity involves "flushing out" a combine by harvesting 60-70 bushels of non-GM grain after a simple 15 minute cleaning of the combine. The latter procedure costs .09 cents per bushel, and the former costs .60 cents a bushel.

Transporting the grain from the farm to the elevator has no additional costs for GMO free producers. Grain trucks are designed to easily dump and easily sweep clean, and therefore pose little risk of contamination.

At the Grain Elevator

An elevator could dedicate certain bins to be permanently used for storing non-GM grains, but this would offer the elevator less flexibility in the number and types of grains it could store within its existing storage bins. With the arrival of GMOs, there are virtually twice as many types of corn, so if an existing elevator wanted to segregate GMOs from non-GMOs, then it would cut in half its capacity to separate grains by high and low quality.

Grain elevators are not designed to be kept "kernel clean." It would be prohibitively expensive to achieve this degree of cleanliness in the pits, boots, conveyor belts, storage bins, distributors, and especially the legs of an elevator. The cost-effective procedure is for grain handlers to dedicate separate grain paths to non-GM and GM grains. Those elevators with multiple grain paths of dump puts, legs, storage bins, conveyor belts, and spouts will be able to practice segregation and identity preservation with lower costs than those without separated grain paths.

Rail and Water Transport

For rail transport, hopper cars are built to receive various types of bulk cargo, and are cleaned after each shipment as a matter of standard procedure, and thus genetic contamination is of little concern. However, shipping identity preserved grain via river barges can be both difficult and costly. Currently, cleaning a barge costs around $300, and can be a difficult and unreliable procedure. The risk varies depending on the type of commodity that had previously been transported. Shipping GMO-free grain by sea is not costlier or riskier than for conventional commodities. Current regulatory requirements ensure that ship holds are cleaned between every shipment.


It is possible to develop verifiable methods for guaranteeing the purity of non-GM seed, grains and processed foods. A Polymerase Chain Reaction is a laboratory process in which a particular DNA segment from a mixture of DNA chains is rapidly replicated, producing a large, readily analyzed sample of a piece of DNA; the process is sometimes called DNA amplification.

Currently, there are many qualitative Polymerase Chain Reaction or "PCR negative" claims being marketed internationally. A PCR negative test shows that a particular genetic component is not present. However, GMO-free claims relying on this test are often misleading and sometimes openly false, as the tests cited are for ingredients where GMOs cannot be reliably tested for or detected, like oils or highly processed ingredients. Only the more expensive and thorough quantitative PCR test can reliably detect the exact presence of foreign genetic material.

In order to detect the presence of herbicide resistant traits, the ELISA (Enzyme Linked Immunosorbant Assay) detects a specific protein that has been captured by an antibody formed for the protein. GMO-free seeds show distinct characteristics when placed on a medium that is moistened with the respective herbicide.

Generally, current procedures lack both uniformity and reliability, and testing methodologies for the literally hundreds experimental GMO varieties that are planted in fields around the U.S. and elsewhere are nonexistent. There is a great need for new testing products and internationally applied testing protocols that can guarantee the integrity of non-GMO products from start to finish.


The StarLink debacle – in which a variety of genetically engineered corn not approved for human consumption in the US was nonetheless mixed with the food supply, both domestic and exported, costing manufacturers up to $1 billion in economic losses – provides a glimpse of the damages that could accrue in the future. The traditional practice of "commingling" or mixing crop varieties during storage and shipment is likely to generate many more liability claims both in the US and internationally.

If the US Environmental Protection Agency continues to define GMOs as "substantially equivalent" to other crops and if open-field testing of unapproved varieties remains commonplace, contamination will become the norm. As testing methodologies advance, detection systems for new varieties will make compliance with international regulations and GMO-free certification systems increasingly more difficult.

Threshold Levels

Because of all the possible contamination points in the current grain handling system, agri-business is promoting "threshold levels" of contamination that would be considered acceptable and marketed as "GMO-free" nonetheless. The industry contends that the costs of identity preservation increase exponentially with each percentage decrease in what would be considered a tolerable level of foreign DNA in consumer products.

The European Union, for example, has proposed a threshold of 1% contamination, while Japan would tolerate up to 5%. Because accuracy is much less important with a higher threshold, the industry is opposing the EU proposal and seeking a higher standard globally.

GM Contamination and Trade

Proposed European Union regulations for labeling GM foods and GMO-free foods would require identity preservation or "traceability" – defined as "the ability to trace and follow a food, feed, food producing animal, or substance through all stages of production and distribution." Further, the European Commission states that food and feed business operators "shall have in place systems and procedures which allow for this information to be made available to the competent authorities on demand."

The EU threshold of 1% for food and feed without triggering labeling requirements allows for some contamination, but the regulation further stipulates that this presence of GMOs must be the result of "adventitious" or technically unavoidable pollination. Responsible parties must be able to demonstrate that steps were taken to avoid the presence of foreign genetic material. Thus, simply assuming a tolerance level of 1% will not satisfy EU regulations.

Each ingredient of any non-GMO-free product imported from the US into Europe, or the product itself if it consists just of one ingredient, will have to be labeled with the words 'genetically modified' or 'produced from genetically modified [name of organism] but not containing a genetically modified organism.'

Under the Cartagena Protocol on Biosafety, all shipments of commingled grains will have to indicate they "may contain" GMOs and importing nations may refuse shipments of GM-foods providing they follow certain procedures. In coming years, more detailed requirements for documenting the presence of GMOs will be negotiated, as well as provisions for compensating the victims of harm caused by GMOs.

If implemented, these regulations may force North American exporters to implement real-time systems to trace the origin of their products back to the farm in order to meet international market demand for GMO-free products. While threshold levels of tolerable contamination would undercut the degree of care required, incentives for developing and maintaining segregated pathways for grain varieties are growing.

Practical Experience

General Mills has pioneered identity preservation practices, undertaken studies to determine the effectiveness of buffer zones and is taking a realistic look at prospects for contamination. The company is working directly with farmers and breeders to learn more about identity preservation, but have found that technological possibilities are way ahead of consumer knowledge.

General Mills has found that approaching the development of non-GM product lines from a perspective of zero tolerance is costly and nearly impossible, but there is a degree of "substantial difference" between types of traditional varieties and that the "performance variation between varieties is greater than believed."

Whole Foods, a natural foods chain, decided to market their store brands as GMO-free. They began by randomly testing products containing corn, soy, canola (rapeseed) or tomatoes. They eventually eliminated the use of corn syrup from all recipes and reformulated many products, at great cost to the company. Certain products had to be discontinued because of the difficulty in finding a manufacturer that would guarantee product integrity.


In the StarLink case, under pressure from the Attorneys General of 16 farm states, the company that engineered the product, Aventis CropScience, voluntarily accepted responsibility for compensating affected farmers, distributors and food manufacturers. But litigation resulting from other types of GMO controversies is mounting rapidly. Claims arising from genetic contamination, violation of technology-user agreements associated with patented GMOs, and regulatory liability are adding swiftly to the burden of the US court system. Until legislation is enacted imposing liability on the companies that make and sell GMOs, those farmers, companies and third party certification programs selling GMO-free products and services are bearing the burden of proof of their GMO-free claims, and being found liable and absorbing the economic costs for adventitious contamination of their products.


Genetically modified seeds, commodities and processed foods have been a source of controversy in international markets since their introduction. At present, the primary incentive for the production of identity preserved non-GMO products is to take advantage of export markets where GMOs have been prohibited or otherwise regulated.

Identity preservation involves seed testing and certification; production, transport and storage on and from the farm; receiving and handling at the elevator; the establishment or use of dedicated processing and storage and distribution facilities; supplier certification and monitoring; development of recognizable and standardized labeling systems; compliance monitoring; GM testing throughout the supply chain; and provisions for appropriately allocating liability in case of errors.

Identity preservation adds costs and complexity to the food system, and failure at any point could result in commingling of a product or mislabeling and related liability claims. But the biotechnology industry has invested deeply in the development of new GMO products. More than 28,000 field test sites have been authorized in the US through 2000, including more than 4,500 in that year alone. Of these, information about the genetic material being tested in two-thirds of the sites was considered "Confidential Business Information" not available to the public.

If the industry expects to successfully market GMO products in the future, investments in segregated pathways for identity preserved products seem to be an unavoidable cost of doing business now.


  • Cert ID Non-GMO Certification, Program Overview
  • David S. Bullock & Marion Desquilbet, "The Economics of Non-GMO Segregation and Identity Preservation."
  • "Knowing Where It's Going: Bringing Food to Market in the Age of Genetically Modified Crops," Minneapolis, MN, September 11, 2001.
  • The Non-GMO Source, August 2001.
  • The Organic Standard, September 2001.
  • Prairie Grains, "Segregating Grain in a Post StarLink World," May 2001.
  • St. Paul Pioneer Press, August 2, 2001.

By Neil Sorensen
Institute for Agriculture and Trade Policy
2105 First Avenue South
Minneapolis, Minnesota 55404
Tel: (612) 870-3412
Fax: (612) 870-4846
Email: nsorensen@iatp.org

IATP is one of the founding members of the Genetically Engineered Food Alert Campaign, a coalition of organizations concerned with the protection of consumer rights, public health and the environment. For more information, visit www.gefoodalert.org