Order Code RS20732
Updated January 10, 2001
CRS Report for Congress
Received through the CRS Web
StarLinkTM Corn Controversy: Background
Alejandro E. Segarra, Agricultural Policy Analyst, and
Jean M. Rawson, Agricultural Policy Specialist
Resources, Science, and Industry Division
StarLinkTM is a corn variety that has been genetically modified to contain an
insecticidal protein derived from a naturally occurring bacterium (Bacillus thuringiensis,
or Bt). The Environmental Protection Agency (EPA) approved the gene-spliced variety
of yellow corn in 1998 for use only as animal feed and set a zero-tolerance level for its
use in human food based on the fact that this particular Bt protein does not break down
easily in the human digestive system, is heat resistant, and could prove allergenic.
StarLink corn was detected in taco shells in mid-September 2000. The StarLink variety
constitutes between 0.4% to 0.5% of total U.S. corn production; however, a larger (and
unknown) amount of corn currently in market channels may be commingled with
StarLink corn. EPA is examining a request from Aventis, the manufacturer, to grant
StarLink a temporary emergency exemption from the zero-tolerance standard. Japan,
which imports 30% of total U.S. corn exports and does not permit StarLink to be
imported for any use, has asked U.S. government officials to make sure that no incoming
shipments contain StarLink-commingled corn. Several bills were introduced in the 106th
Congress to require labeling of foods containing genetically modified organisms (GMOs).
In addition, a bill was introduced at the end of the 106th Congress (S. 3184) to amend the
Federal Food, Drug and Cosmetic Act to require pre-market consultation and approval
for foods containing GMOs. This report will be updated as events warrant.
The presence of StarLinkTM corn in food has become the first test case of
contamination of the food supply by a genetically modified organism (GMO). Among the
issues this raises for Congress are: What steps might help alleviate the immediate problems
for farmers, grain elevators, exporters and trading partners? Are further changes in the
current statutory or regulatory framework needed to address the food and environmental
safety issues related to agricultural biotechnology? Can regulatory policies be changed in
such a way that support for innovation in crop and food technologies is not undermined?
Congressional Research Service ˜ The Library of Congress
StarLink TM & EPA: Regulatory Timeline
March 14, 1997. EPA issues an
experimental use permit (EUP) to Plant
Genetics Systems (PGS) to test corn seeds
containing the Cry9C protein in 3,305 acres
in 28 States.
August 8, 1997. EPA announces an
application from PGS to register the Cry9C
pesticide under FIFRA.
September 19, 1997. EPA announces that
PGS asked for a full exemption of a
tolerance for Cry9C residues in or on all
raw agricultural commodities under
November 26, 1997. EPA announces PGS’
request for a temporary “split” exemption of
a tolerance for residues for Cry9C in corn
for animal feed only under FFDCA.
April 10, 1998. EPA issues a final rule
establishing the temporary “split” tolerance
exemption for Cry9C.
May 22, 1998. EPA issues a final rule
granting a “split” tolerance exemption to
April 7, 1999. EPA announces that AgrEvo
USA had filed a petition to exempt from
tolerance residues of Cry9C in or on all raw
December 21, 1999. EPA asks for input
and comments on how to assess potential
allergenicity of Cry9C in establishing “a
reasonable certainty of no harm” before
considering AgrEvo’s request for a full
exemption from tolerance under FFDCA.
February 29, 2000. EPA’s Scientific
Advisory Panel (SAP) meets to consider
and define the issues and methods in
determining food allergenicity of Cry9C.
April 5, 2000. A National Academy of
Sciences (NAS) report states that Cry9C
raises concerns of allergenicity.
August 9, 2000. EPA announces new
review process for plant-pesticide
registrations, including Cry9C, in view of
October 31, 2000.
Aventis’ submission of additional data and
outlines review process.
December 5, 2000. EPA’s SAP found
This report examines the events that
led to the current situation and provides
an overview of its impacts.
What is StarLinkTM Corn?
StarLink is a trademark for several
genetically modified corn hybrids
produced by Aventis Crop Science of
Research Triangle Park, N.C. (a
German-French life sciences consortium)
and distributed through several seed
companies. StarLink hybrids contain a
plant pesticide protein (Cry9C) derived
from a common soil microbe (Bacillus
thuringiensis, or Bt), which kills certain
destructive pests of corn such as the
European corn borer. StarLink also is
one of a handful of the currently
approved genetically modified (GM)
crop varieties that contains “stacked
more than one
commercially desirable transgenic trait at
StarLink contains: (1) the
insecticidal Bt Cry9C protein; and (2)
genes from the bacteria Streptomyces
hygroscopicus, which makes StarLink
tolerant to a commonly used broadspectrum herbicide.
Government Review and
Approval Process for StarLink
StarLink’s journey through the
regulatory review and approval process
was typical for a GM crop in the United
States.1 As with all crops bioengineered
The Coordinated Framework for Regulation of Biotechnology of 1986 establishes agency
responsibilities and regulatory policies for biotechnology products derived from existing statutes
[Federal Register, June 26, 1986 (51 FR 23302)]. An in-depth discussion of regulatory issues
to contain an insecticide, StarLink required
regulation under two different authorities:
(1) the Federal Insecticide, Fungicide, and
Rodenticide Act (FIFRA),2 which requires
EPA to register and label pesticides; and (2)
the Federal Food, Drug and Cosmetic Act
(FFDCA)3, which requires EPA to establish
a safe tolerance level for pesticides used on
(or genetically engineered into) foods, and
vests enforcement authority in the Food and
Drug Administration (FDA).
Testing for GMO’s has become
central to determining the presence of
StarLink corn. Two tests have been
Strip Test - confirms the presence or
absence of proteins (like the Cry9C
protein). The test costs $5-7 and is used
by grain elevators. Test can detect
Cry9C down to 1 in 400 kernels
(0.25%) and is used mainly for detection
of GMOs in raw commodities.
Although health safety tests had found
that Cry9C did not resemble any known
allergens, results from other tests did not
Polymerase Chain Reaction (PCR)
allow experts to completely rule out the
test- confirms the presence of genetic
material or DNA associated exclusively
potential for allergenicity. There were two
with StarLink genes. This is the test
particular concerns: one test showed that
used by environmental groups, and the
Cry9C protein could survive cooking or
FDA to detect StarLink. PCR test costs
processing, and another determined that
of dollars and can take several
Cry9C is hard to digest. When in 1997 the
days to complete. The test can detect
original patent holder asked EPA to allow
StarLink DNA down to 1 in 100,000
Cry9C corn to be registered for use only for
kernels, or less than 1 kernel in a bushel.
livestock feed and industrial purposes, EPA
exempted the plant-pesticide from the
requirement for a tolerance in animal feed,
thus granting it a so-called split registration. EPA required the company to take all actions
needed to prevent StarLink from getting into the human food chain. Giving split
registration is a common practice with conventional chemical pesticides, as each
registration (or tolerance) specifies the crops on which use is allowed.
In 1999, the AgrEvo USA seed company, the next owner of the StarLink patent,
asked EPA to set a tolerance for use in food products. EPA responded by asking for input
from industry and academia on methods to ascertain Cry9C’s potential for allergenicity and
by convening a Scientific Advisory Panel in early 2000 to review the issue. Meanwhile,
in April 2000 the National Academy of Sciences issued a separate report reiterating
in food biotechnology can be found in CRS Report RL30198, Food Biotechnology in the United
States: Science, Regulation, and Issues, by Donna Vogt & Mickey Parish.
FIFRA (7 USC 136 et seq.) regulates the distribution, sale and use of pesticides in the United
States. EPA defines registration as the formal listing of a pesticide before it can be sold and
distributed in intrastate or interstate commerce. To register a pesticide the burden of proof is
on the producer to demonstrate no “unreasonable” adverse effects on the environment.
FFDCA requires that the EPA establish a tolerance level for pesticide residues in raw
agricultural commodities (21 USC 346a). EPA may determine that a pesticide (e.g., Cry9C )
is safe and exempt from the requirement of a tolerance if it finds, with “reasonable
certainty”that aggregate exposure to residues will not cause harm.
concerns about Cry9C’s possible allergenicity and advising the EPA to improve the testing
on the human and environmental impacts of Bt crops.4
How Events Unfolded
On September 18, 2000, the Washington Post reported that tests ordered by a
coalition of groups opposed to biotechnology had found traces of genetic material from
StarLink in Kraft’s taco shells in grocery stores in Washington, D.C. Kraft voluntarily
recalled all taco shells from grocery stores 4 days later, after confirming the finding.
Several other recalls by retailers have taken place subsequently, and in November the FDA
exercised its enforcement authority by recalling over 300 corn products.
On September 26, 2000, Aventis (the third and current owner of the StarLink patent)
instructed its seed distributors in the United States to stop sales of StarLink seed corn for
planting in 2001; shortly thereafter the company voluntarily agreed to cancel its EPA
registration of StarLink for feed and industrial use, thus taking the product off the market.
On October 25, Aventis submitted new safety information and asked EPA to grant a
time-limited approval of up to 4 years for the presence of the corn in human food.
According to Aventis, four years is how long it could take for all StarLink-contaminated
corn to clear food channels.
On September 29, Aventis agreed with the U.S. Department of Agriculture (USDA)
and EPA to purchase all of the 2000-crop year StarLink corn, offering farmers a 25-cent
premium over the price of corn on October 2, which was $1.9925/bushel. Under the
program, USDA will purchase the corn from the farmers and assure that it is distributed
into feed and industrial channels only. Aventis will reimburse USDA for the cost. Early
estimates of the cost to the company of implementing the buy-back program have ranged
between $60 to $100 million and involve close to 80 million bushels.
International repercussions concerning StarLink began on October 24, 2000, when
the Consumers Union of Japan found traces of the variety in snack foods and in animal
feed. Under Japanese regulations, StarLink is not approved for any use and there is a zero
tolerance threshold for StarLink in corn imports. Korea, the second largest market for
U.S. corn, also has recalled corn products after finding StarLink traces in imported taco
shells in early November. No immediate repercussions are expected in Europe, where
imports of U.S. corn are small (0.1% of U.S. exports.)
The Current Situation
StarLink down on the farm. According to Aventis, farmers planted StarLink on
248,000 acres in 26 states in 1999. In 2000, farmers planted the variety on 352,000 acres
in 29 states. These figures represent 0.32% and 0.44% of corn acreage in the United
States in 1999 and 2000, respectively. Production estimates for StarLink are 38 million
bushels (1999) and 54 million bushels (2000), which represent between 0.4% to 0.5% of
U.S. crop production. However, in accordance with EPA rules, an additional 30 to 40
million bushels of non-StarLink corn harvested from buffer acres must be included in total
National Research Council. April 2000. Genetically modified pest-protected plants: Science
and Regulation. National Academy Press. Washington, D.C. 260p.
production figures.5 As of late October, Aventis had located all but 1.2 million bushels of
the 2000 StarLink crop. The 1999 crop is so far along in the marketing chain that Aventis
cannot determine its whereabouts. At the farm level, most producers already have sold
their 1999 StarLink crop; they will be paid for the 2000 crop at the level set in the USDAAventis buy-back program (see above).
StarLink in the market. Aventis maintains that about 12% of the 2000 crop, 9.6
million bushels, could be illegally present in food products. Aventis is working to forestall
further contamination by designating specific elevators for delivery and distribution into
approved feed and industrial use outlets. However, the extent of commingling of StarLink
with non-StarLink corn in food channels is harder to pin down. Media reports vary and
high estimates abound because it does not take very much StarLink in a sample to result
in a positive finding (see box on Testing). For example, experts at Iowa State University
claim that a large proportion of corn in Iowa elevators may contain traces of StarLink.6
Most experts agree that factors such as the handling of the corn from buffer strips and the
possibility of StarLink pollen drifting into neighboring fields could elevate contamination
estimates substantially. In addition, there is suspicion that the prevalent StarLink
contamination in food currently on the shelves could be from the 1999 StarLink crop.7
According to USDA, 1.8 billion bushels from the 1999 season remain in elevators as
carryover. This represents close to 20% of that year’s crop.
StarLink exports. In early November 2000, USDA and Japan’s Health Ministry
implemented a plan to assure that no commingled corn is shipped to Japan. The plan
provides that USDA will test for the presence of StarLink at domestic shipping locations,
again on barges and railcars, and finally at export points. The protocol pertains to corn
imports for food and feed use. Meanwhile, in response to a request from USDA and the
U.S. grain industry, the Japanese Agriculture Ministry has agreed to review the safety of
StarLink corn as an animal feed. The United States sold 600 million bushels of corn to
Japan in 1999 with an estimated value of $1.45 billion. Sales to Japan represent 30% of
U.S. corn exports. Late in 2000, USDA reports showed that corn sales to Japan were
decreasing, but an agreement between the government of Japan and USDA in December
promised to reverse the trend. Under the agreement, Japanese inspectors monitor tests of
corn feed shipments and certify them as StarLink-free.
Liability. The most frequently asked question is who is responsible for StarLink’s
illegal appearance in food products. EPA officials have said that Aventis, as a condition
for its license, had the responsibility to ensure that the corn did not get into the human
The 2000 StarLink Bt Grower Agreement states that: “In accepting StarLink corn, grower
agrees to direct the harvested grain and grain grown within 660 feet of the StarLink grain
towards domestic feed (e.g. animal feed) and/or non-food industrial purposes. Grower agrees
not to use this grain for food use or allow it to enter grain export channels.”
Personal Communication with Dr. Charles Hurburgh, Professor at the Department of
Agricultural & Biosystems Engineering. Iowa State University. November 2, 2000.
Associated Press. November 3, 2000. Corn recall expands to stores, restaurants across
country. Washington Post p.A5.
food supply. Aventis has said that it required farmers who grew StarLink to sign
agreements to use the corn only for animal feed or industrial use and to treat non-StarLink
corn harvested from buffer strips as part of the StarLink crop. In addition, Aventis has
claimed that seed bags carried a label detailing these requirements. Many agree that the
issue of liability is likely to be under judicial review for a long time, as farmers, elevators,
processors, and others seek redress from losses that have been estimated in the hundreds
of millions of dollars.8
Split Approvals for GM Crops by EPA. Critics have questioned EPA’s decision
to grant StarLink approval for animal feed and not for human food. Some are asking EPA
to withhold approval of biotechnology crops until they have clearance to be used in food.
These critics point to the StarLink incident as an example of how the “split” approval
policy has gone wrong and threatens the confidence of consumers and foreign markets.9
Others have argued that split registrations for GM varieties should be permitted on a caseby-case basis – for example, for those containing edible vaccines or for industrial-use-only
cultivars, and where segregation from food varieties can be better ensured.
Mandatory Pre-Market Approval and Review. This incident has raised serious
questions about the adequacy of the current system, especially in the areas of monitoring
and enforcement. Some are calling for requiring a fully validated testing procedure for
identifying DNA in crops and finished goods as a precondition to approval by EPA.
Others are calling for a mandatory review of each new GM variety before it reaches the
market by panels composed of state and federal agencies, industry, exporters, academia
and other interest groups. Critics of these proposals argue that it would become
increasingly difficult to register or introduce biotechnology innovations under such a
system, and that the increasing genetic complexity of second and third generation GM
crops would make testing for individual traits an expensive proposition.
Several bills were introduced in the 106th Congress which addressed the issue of
mandatory labeling of GM foods.10 In response specifically to the StarLink events that
began in September 2000, Senator Durbin introduced a bill late in the 106th Congress that
would have amended the Federal Food, Drug and Cosmetic Act to require pre-market
consultation and approval for GM foods (S. 3184). The bill proposed to codify the existing
system of voluntary consultations with the Secretary of Health and Human Services, giving
FDA the authority to regulate genetically engineered food and to require public
participation in the decisions. Bill provisions would have also authorized FDA to test
products on the market to determine whether unapproved genetically engineered materials
K.T. Arasu, Reuters News Service. “Anger in Iowa over gene-altered corn controversy.”
November 2, 2000.
See Kraft Foods (September 22, 2000) Official Statement; Grocery Manufacturers of
America. (September 22, 2000) Press Release; National Corn Growers Association.
(September 29, 2000) “Hot of the Cob: Grains Council, NCGA Respond to Corn Concerns in
Bills include H.R. 3377 (Kucinich) and S. 2080 (Boxer). For overview see CRS Report
RS20507, Labeling of Genetically Modified Food, by Donna Vogt & Brian Jackson.