TWN report on Starlink scandal



The discovery that a genetically engineered variety of corn which is not approved for human consumption has inadvertently made its way into human food products in the US and Japan has raised widespread alarm in those countries about testing, safety regulation, segregation, and labelling of genetically engineered foods. In September, an independent scientific laboratory found traces of StarLink corn in samples of taco shells being sold in US supermarkets. More than 300 brands of food products have since been recalled from supermarkets, grocery shelves, and restaurants throughout the US. More products are being recalled and tested even now since the extent of contamination is still unknown.

StarLink corn, created by Aventis CropScience, is not approved for human consumption by the US Environmental Protection Agency (EPA) because it contains the Cry9C protein, which has been classified as a potential allergen.

While hundreds of products have been recalled from US supermarkets and restaurants, the US continues to export corn that may be contaminated with StarLink to Asia, Latin America, and Europe. The US government has officially approved corn contaminated with StarLink for exports when its own regulatory authority is not convinced that StarLink is safe for human consumption. Once exported, StarLink will almost certainly enter into the food chain of the importing countries, which may not have been provided with sufficient information on the potential hazards of the corn. StarLink has already been detected in food products in Japan, the biggest buyer of US corn exports, where it is banned altogether. The US is now supposed to test all corn exports bound for Japan, but there no mandatory testing of US corn shipments to other countries around the world is required.

StarLink is no longer allowed to be planted in the US for agricultural purposes, and Aventis CropScience has begun to buy back all of this year’s StarLink corn from the farmers. Aventis is meanwhile trying to obtain a temporary approval for StarLink from the EPA for four years, the time it says it will take for all StarLink corn grown since 1998 to be purged from the food system.

More recently, it was discovered that the Cry9C protein in StarLink has turned up in another variety of corn. The protein was found in a corn hybrid produced in 1998. The US Department of Agriculture (USDA) attributes this either to cross pollination in the field or to mishandling of the seed during production and distribution.


StarLink is the trade name of a variety of genetically engineered yellow corn originated by Aventis CropScience, a subsidiary of European biopharmaceutical corporation Aventis SA. StarLink is genetically modified to contain Bacillus thuringienes (Bt), a plant pesticide resistant to the European corn borer pest. It is the only variety of corn that contains the Bt subspecies tolworthi Cry9C protein, which has been labelled by the EPA as a potential allergen.

Based on this evidence, the EPA ruled in 1998 that StarLink corn could only be used for animal feed and for industrial uses such as ethanol production, and not for human consumption. Aventis was to be responsible for informing corn farmers on appropriate identification and segregation procedures to keep StarLink separate from conventional crops, and prevent it from entering the food supply.

10,000 acres of StarLink corn were planted throughout the US in 1998, when the variety was first introduced. 250,000 acres were planted in 1999, and 350,000 acres were grown this year, mostly in Iowa and other Great Plains states.


Evidence that Cry9C is heat stable and resistant to degradation in gastric juice shows that StarLink may cause allergic reaction in some people. These two properties are among the most important indicators of allergenicity. At least 15 formal reports have been lodged in the US by people who claim to have suffered allergic reaction after eating corn products.

In other Bt corn varieties, the Cry protein is concentrated in the plant’s leaves and pollen. StarLink corn produces substantial amounts of Cry9C in kernels and roots as well as leaves. Cry9C levels in corn kernels is 10 to 400 times as high as that of Cry proteins in other Bt corn varieties. As there is no known history of human dietary exposure to the Cry9C protein, it is difficult to know its long-term effects on human health.

In addition, recent scientific evidence has shown that there are significant health hazards in Bt toxins in general (see Appendix 1).

StarLink is also resistant to glufosinat ammonium. It is thus insect resistant and herbicide resistant. However, no research has been conducted by the EPA to determine whether such a combination (multiple resistance) could have other unwanted and unintended side-effects.

StarLink also contains ampicillin resistance marker genes, and the cauliflower mosaic virus (CaMV) promoter. Scientific literature on the CaMV promoter has revealed that the CaMV promoter has a ‘recombination hotspot’ – where the DNA tends to break and join up with other DNA. This means that parts or all of the transgenic DNA is more likely than the plants own DNA to jump out of the genome and successfully transfer horizontally to unrelated species. The major consequences of the horizontal gene transfer of transgenic DNA are the spread of antibiotic resistance marker genes (present in StarLink) and the generation of new bacteria and new viruses that cause diseases from the many bacterial and viral genes used.


Below, we set out key events which took place in relation to the Starlink scandal:

US Environmental Protection Agency approves StarLink for animal feed but not for human food or export. The registration contained the following language: “It is a violation of federal law to use this product in a manner inconsistent with labelling. Keep out of lakes ponds or streams. Do not contaminate water by cleaning of equipment or disposal of wastes. All field corn containing the plant-pesticide that is sold or distributed by Aventis CropScience USA LP or a cooperator or licensee of Aventis, must be accompanied by informational material that contains the following… “Seeds expressing the Cry9C protein should be planted at a maximum of 40,000 seeds per acre on the site. Any seeds, plants or plant materials in the StarLink field, or within 660 feet of the field, should be used domestically for animal feed or non-food industrial purposes. None of the seeds, plants, or plant materials in the StarLink plot, or within 660 feet of the field, may be used for food uses or may enter international commerce.”

August 2000:
Genetically Engineered Food Alert [a coalition of US non-governmental organisation] submits seven boxes of Taco Bell taco shells (produced by Kraft Foods) purchased from food stores in the Washington, D.C. area to Genetic ID, an independent scientific laboratory, for testing. Genetic ID performs a Varietal IDSM test on the taco shells, specifically screening for StarLink, a genetically-engineered variety of corn not approved for human consumption.

The Genetic ID test reveals the presence of StarLink corn in the taco shells at a concentration of about 1%. The test is repeated three times and each test is run in duplicate. All duplicate tests confirm the presence of StarLink at 1% concentration. StarLink corn contains the Cry9C protein that may cause allergic reaction in humans and is not approved for human consumption by the EPA.

Aventis applies to plant StarLink in South Africa for research trials.

September 18:
Genetically Engineered Food Alert announces that, for the first time in US history, a genetically modified organism (GMO) which was not approved for human consumption had entered the food supply.

September 22:
Kraft Foods announces recalls on nearly 3 million Kraft taco shells from supermarkets.

September 29:
Aventis CropScience announces an agreement with three federal agencies to buy up all of this year’s StarLink crop to ensure it would not enter human food channels.

Aventis urges farmers to store StarLink corn until further notice, and questions them about the handling of the grain. It is discovered that not all farmers had signed required contracts obligating them to follow proper procedures to prevent StarLink from entering food channels.

The FDA posts a recall on over 300 brand-name corn products available at US supermarkets and groceries following the discovery that StarLink corn has made its way into the human food chain.

A Kellog Co. cereal plant in Memphis shuts down because it is unsure whether its corn flour supply is contaminated with StarLink.

October 6:
US corn exports are halted after the US Department of Agriculture states, in a letter to the grain industry, that, “StarLink corn may not be lawfully sold for use in human food or for export.”

October 12:
Stephen Johnson, Deputy Assistant Administrator for Pesticide Programs at the EPA, states: “At the strong urging of the EPA, Aventis is announcing today that they are cancelling the registration of StarLink corn. This means that StarLink corn can no longer be planted for any agricultural purpose. Today’s agreement will ensure that in the future no new StarLink corn will be grown and none will find its way into processed foods like taco shells.”

October 13:
Mission Foods, the largest manufacturer of tortilla chips in the US, recalls all of its tortillas, taco shells and snack chips. Azteca Milling, a Texas based flour mill which supplied corn flour to Kraft and Mission, recalls all of its flour made from yellow corn.

October 25:
The No Genetically Modified Food Campaign in Japan [a coalition of Japanese non-governmental organisations] announce that traces of StarLink have been detected in Kyoritsu Shokuhin corn-flour baking-mix. The StarLink corn scare soon reaches Japanese Parliament. Concern spreads among Japanese importers over talk that StarLink corn was found in a 55,000-tonne shipment of US corn.

A delegation from the US government and the Grain Council travel to Japan to assure the Japanese government that US corn exports containing StarLink will not be sent to Japan, where StarLink is not approved for both human and animal consumption.

October 27:
The US lifts a ban on the export of corn tainted with StarLink, with the exception of shipments to Japan. The US Department of Agriculture allows US corn exports inadvertently commingled with traces of StarLink under certain conditions. The details of these conditions were unavailable.

October 30:
In Chicago, a lawsuit is filed by a man who claims to have suffered an allergic reaction due to eating Kraft Taco Bell.

October 31:
Aventis SA announces that StarLink has been grown on an experimental basis in other countries besides the US, but declined to name them, and that they are planning to develop StarLink in other corn-growing countries.

November 3:
After two weeks of talks, the USDA and Japanese officials reach an agreement that the US will conduct tests on corn shipments to Japan, beginning November 15. Testing will only be carried out on corn intended for human consumption and does not include the testing of animal feed or processed food.

November 13:
After a preliminary assessment on whether new scientific data submitted by Aventis in an attempt to prove that StarLink is safe for human consumption, the EPA announces that it is not convinced by the claim that StarLink poses no allergic risks to humans.

StarLink is discovered in Japan in US shipments of animal feed. 10 out of 15 corn samples taken from ships and conveyor belts are found to contain StarLink.

November 15:
Aventis SA announces that it will spin off its agrochemical business, Aventis CropScience, in order to focus on pharmaceuticals.

Corn buyers in South Korea, the second largest importer of corn in the world, want the US to pay the cost of ensuring that corn exports to South Korea are free from StarLink. Korea’s largest importer of corn for processing, Kocopia group, meets with the US Grains Council with the intention of making this reimbursement request to the US Department of Agriculture.

November 21:
Aventis CropScience announces that the Cry9C protein has turned up in another variety of corn. The protein was found in a corn hybrid produced in 1998. The USDA attributes this either to cross pollination in the field or to mishandling of the seed during production and distribution.

November 22:
El Salvador announces that it has prohibited the import and sale of some 75 products containing genetically engineered corn related to the StarLink brand.

November 28:
In a television interview, an Iowan farmer alleges that despite planting a buffer zone, his entire non-StarLink crop was still contaminated.

The American Seed Trade Association meets with the USDA to urge for a ‘tolerance’ level in seeds – that bags of seed could contain some amount of genetically engineered material and still be considered non-genetically engineered, so as not to disrupt world trade.

November 29:
A Reuters article reports that 44 Americans have complained of becoming ill after eating foods containing StarLink.


It is difficult to estimate how much corn in human food channels has been contaminated with the StarLink variety of genetically engineered corn. The StarLink scare reveals the failure of the US agricultural regulation system to identify and segregate crops grown from genetically engineered seeds from conventional grains, as well as the deficiencies of the food regulation system intended to keep unapproved, potentially harmful substances out of the food supply. It also has serious implications for countries that import US corn or corn products.

Many countries do not have a proper system to regulate genetically modified organisms and do not have clear policies on such crops and food products. Since US corn exporters are unsure of the restrictions of many importing countries, corn shipments to most countries are not being routinely tested for StarLink, with the exception of those intended for human food consumption in Japan.

Many US corn farmers say they were never told to keep StarLink corn separate from conventional grain, and were not required to sign contracts on proper handling procedures for the genetically engineered variety. StarLink corn kernels were mingled with non-StarLink corn in bins, silos and grain elevators, processed into flour at mills, and mixed with other corn flour at food factories.

Some farmers also claim they were unaware that a 660-foot (200-meter) buffer zone was required to prevent StarLink from cross-pollinating with other varieties of corn. All corn cross-pollinates, making it hard to determine how much non-StarLink corn has now been contaminated with StarLink genes.

Meanwhile, the Cry9C protein in StaLink has been discovered in another hybrid corn variety produced and distributed by Garst Seed Company, under licence from Aventis. This indicates that cross-pollination or horizontal gene transfer has probably occurred. Reports from farmers indicate that despite adhering to the buffer zone rule, contamination still occurred. The presence of the protein in another non-StarLink corn variety raises further questions about how much more corn has been contaminated with the potentially allergenic Cry9C protein.

Aventis has initiated a US$100 million buy-back program for all remaining StarLink corn from US farmers. According to Aventis, about 12 percent of this year’s StarLink crop, or 9.6 million bushels, has inadvertently ended up in food products for human consumption. These bushels had been delivered to more than 350 grain elevators throughout the US. Government and industry officials are uncertain how much of the corn has been properly segregated and identified.

More than 300 kinds of taco shells, tostadas and chips made with corn flour have been recalled by top US companies including Wal-Mart Stores Inc., Wendy’s fast-food restaurants, and grocery chains Safeway, Albertson’s Inc., Kroger Co., Kash-n-Karry, Food Lion and Vons. U.S. food manufacturers have been forced to launch costly and widespread testing of corn supplies to avoid contamination.

The USDA claims that the contaminated corn will not be used in the U.S. government’s food assistance programs for poor nations. Tim Galvin administrator of USDA’s Foreign Agricultural Service stated that, “all of the StarLink corn collected from farmers is to be strictly segregated and used only for domestic livestock feed or ethanol production”.

However, on October 27, the US government lifted export restrictions on corn tainted with StarLink, allowing untested shipments to be sold to Asia, Latin America, and Europe.

Meanwhile, Aventis is trying to seek a temporary approval for StarLink, which in effect would clear them of liability for any health complications that may arise from consuming the unapproved corn variety. The EPA is considering whether to give temporary approval for the use of StarLink in human food for four years. Aventis claims that it will take four years for all StarLink corn grown since 1998 to make its way through food plants, stores and consumer pantries.


In Japan, StarLink corn is not approved for either human or animal consumption. In October, the No Genetically Modified Food Campaign in Tokyo detected the genetically engineered grain in corn flour baking-mix manufactured by Kyoritsu Shokuhin, which uses raw corn imported from the US. In November, StarLink was found in US shipments of animal feed. Japan imports 4 million tonnes of corn for human consumption and 11 million tonnes for animal feed annually, making it the world’s leading importer of corn. Most of this corn is imported from the US, accounting for nearly one third of total US corn exports.

USDA and Japan have now signed an agreement that the US Department of Agriculture will test corn shipments bound for Japan starting November 15 to prevent StarLink corn from contaminating the food supply there. Testing will only be carried out on corn intended for human consumption. The agreement does not include corn for animal feed, or corn-based food products.

Corn samples will be removed from U.S. barges and railcars and tested for StarLink residue. If no StarLink corn is detected, the railcar or barge will be sealed and its contents sent on to Japan. The Japanese government will also conduct random tests to confirm the shipments are free of StarLink. However, spokespeople from Japanese trade houses have said that these latest US measures fall short of full assurances that corn imports from the US are safe and free of StarLink.

A strict new law goes into effect in Japan on April 1, 2001, that sets a zero tolerance for the import of unapproved agricultural products, under which importers can face severe fines and prison terms for importing unapproved varieties of corn into Japan.

Meanwhile, hundreds of products have also been recalled in South Korea, the world’s second largest importer of US corn. Corn buyers in South Korea want the US to pay for the cost of ensuring that corn exports to South Korea are free from StarLink.

APPENDIX 1: Bacillus thuringiensis and its toxins as biopesticides

Prof. Joe Cummins, University of Western Ontario
(Professor Joe Cummins produced the following report on Bt toxins for the Institute of Science in Society, UK)

Biopesticides are microbes or natural chemicals produced by organisms that are used to control disease causing organisms (pests) such as insects or bacteria. In the United States the Environmental Protection Agency (EPA) regulates plant pesticides used directly or as a part of genetically modified (GM) crops. Bacillus thuringiensis (Bt) and its toxins are far and away the most significant biopesticides. Bacillus thuringeinsis is a common spore forming bacterium. Certain of its varieties produce toxins that are effective in controlling specific insect pests ,as well each variety may produce a number of toxins of varying toxicity and specificity. Normally GM crops are modified with a single toxin gene from among a number available to deal with a particular insect pest, frequently the toxin genes are synthetic copies of the bacterial gene. The toxin proteins bind to the cell membrane at particular target site and create pores that enhance water uptake into the cell, ultimately causing that cell to burst. The toxins used with GM crops are selected so that insect cells are attacked while mammalian cell are not. In bacterial biopesticides some toxins do bind to mammalian cells but overt toxicity to mammals is prevented by the acid environment of the gut (the insect gut is normally alkaline).

Bacillus thuringiensis spores are normally applied to crops as a biopesticide, such spores are known to cause allergy in farm workers (Bernstein, I, Bernstein, J, Miller, M, Tiewzieva, S, Bernstein, D, Lummus, Z, Selgrade, M, Doerfler, D and Seligy, V “Immune responses in farm workers after exposure to Bacillus thuringiensis pesticides” 1999 Environ Health Perspect 107,575-82). The spores are normally washed off crops prior to marketing so do not pose a threat to consumers. The toxins in GM crops are a part of the cells of the crop and cannot be washed out to the crop.

Psuedomonas flourescens genetically modified with toxin gene from Bt toxins are marketed as encapsulated Bt toxin. Such products have been marketed to organic producers without acknowledging that the products are genetically modified.

The EPA listing and reviews of Bt pesticides and toxins are listed on the EPA website:
Bacillus thuringiensis Cry1IA(c) & Cry I(c) delta-endotoxin in killed Pseudomonas fluorescens (006457)
Bacillus thuringiensis Cry1A(b) delta-endotoxin and the genetic material necessary for its production in corn (006430)
Bacillus thuringiensis Cry1A(b) in corn from PV CIB4431 (006458)
Bacillus thuringiensis Cry1A(c) delta-endotoxin and the genetic material necessary for its production in cotton (006445)
Bacillus thuringiensis Cry1F protein and the genetic material necessary for its production (plasmid insert PHI8999) in corn plants (pending)
Bacillus thuringiensis Cry3A delta-endotoxin and the genetic material necessary for its production in potato (006432)
Bacillus thuringiensis Cry3Bb protein and the genetic material necessary for its production (Vector ZMIR14L) in corn plants (pending)
Bacillus thuringiensis K Cry1A(b) delta-endotoxin and the genetic material necessary for its production in corn produced by HD-1 gene from PV pZ01502 (006444)
Bacillus thuringiensis K Cry1A(c) delta-endotoxin and the genetic material necessary for its production in corn (006463) 4/00
Bacillus thuringiensis K Cry1C in killed Pseudomonas fluorescens (006462)
Bacillus thuringiensis subsp. aizawai (006403)
Bacillus thuringiensis subsp. aizawai GC-91 (006426)
Bacillus thuringiensis subsp. israelensis (006401)
Bacillus thuringiensis subsp. israelensis EG2215 (006476)
Bacillus thuringiensis subsp. kurstaki (006402)
Bacillus thuringiensis subsp. kurstaki BMP123 (006407)
Bacillus thuringiensis subsp. kurstaki delta-endotoxin in killed Pseudomonas fluorescens (006409)
Bacillus thuringiensis subsp. kurstaki EG2348 (006424)
Bacillus thuringiensis subsp. kurstaki EG2371 (006423)
Bacillus thuringiensis subsp. kurstaki EG2424 (006422)
Bacillus thuringiensis subsp. kurstaki EG7673 Coleoptera Toxin (006447)
Bacillus thuringiensis subsp. kurstaki EG7673 Lepidoptera Toxin (006448)
Bacillus thuringiensis subsp. kurstaki EG7826 (006459)
Bacillus thuringiensis subsp. kurstaki EG7841 (006453)
Bacillus thuringiensis subsp. kurstaki M200 (006452)
Bacillus thuringiensis subsp San Diego delta-endotoxin in killed Pseudomonas fluorescens (006410)
Bacillus thuringiensis subsp. tenebrionis (006405)
Bacillus thuringiensis subsp tolworthi Cry9C delta-endotoxin and the genetic material necessary for its production in corn fm PV pRVA9909 (006466)

In general the EPA reviews of the Bt and toxins biopesticides roundly ignored the finding that Bt was allergenic to farm workers. The EPA review of the Bt toxin Cry 9 is found at:
“The results of intraperitoneal injection of corn powder extracts into BN rats indicate that both the control and transgenic corn powders are able to induce IgE or reaginic antibody responses by the PCA assay. The use of corn powder immunogen decreases the rate of the immune response to the Cry9C protein compared to the bacterial preparation. However, the lowest responding dose for Cry9C was similar for the two preparations (between 0.1and 0.4 µg Cry9C). The control challenge test with the heterologous antigen of control corn powder or transgenic corn powder in the day 42 sera samples indicated that there was significant reactivity from the corn portion of the extracts themselves in the PCA assay. It is unclear, given this background reactivity, how conclusions can be made about the reactivity of the Cry9C protein alone. The PCA results from oral sensitization with ovalbumin II, control corn extract, bacterial Cry9C and transgenic corn (apparently supplemented with bacterial Cry9C) indicated that an IgE or reaginic antibody response was elicited in naïve Sprague-Dawley rats. Ovalbumin sensitized serum produced a low frequency of responders and a weak dose response between the 5.0 and 50.0 mg/kg dose levels on days 28 through 42. The control corn also produced a positive oral sensitization response but this was only examined at the 50 mg/kg dose. Oral dosing with bacterial Cry9C gave a positive PCA response as did the Cry9C amended transgenic corn extract. The frequency of response to bacterial Cry9C began to diminish in day 42 sera. The Cry9C amended transgenic corn had a higher frequency of responders and the frequency remained high on day 42 PCA response. Western blot analysis indicated that Cry9C protein bands could be recognized in the rat sera from both exposure routes.”

These results are an allergic (IgE) response was associated with Cry9 in corn powder. Considering that the Cry 9 containing corn was fed to millions of farm animals and probably as many humans eating corn products contaminated with corn designated only for human use, any evidence of IgE response to Cry9 corn should be made public, and not be allowed to be buried by bureaucrats protecting the interests of multinational corporations.

Finally a list of biopesticides approved by the US EPA for human consumption follows:

Plant-Pesticide Protein
Approved Dietary Use
40 CFR Citation

Watermelon Mosaic Virus-2 Coat Protein
All Food Commodities

Zucchini Yellow Mosaic Virus Coat Protein
All Food Commodities

Potato Virus Y Coat Protein
All Food Commodities

Papaya Ringspot Virus Coat Protein
All Food Commodities

Cucumber Mosaic Virus Coat Protein
All Food Commodities

Potato Leaf Roll Virus Replicase Gene
All Food Commodities

Bacillus thuringiensis Cry3A Protein

Bacillus thuringiensis Cry1Ac Protein
All Plant Raw Agricultural Commodities

Bacillus thuringiensis Cry1Ab Protein
All Plant Raw Agricultural Commodities

Bacillus thuringiensis Cry9C Protein
See: FR Notice
Corn Used for Feed; As Well As Meat, Poultry, Milk, or Eggs Resulting From
Animals Fed Such Feed

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