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Herculex® RW Safety Assessment Summary

Throughout the development of products derived through biotechnology, DuPont meets the highest standards to ensure product quality and safety for farmers and consumers. On the basis of rigorous testing, regulatory agencies concluded that Herculex RW (HXRW; event DAS-59122-7) is as safe as conventional corn. HXRW has received full food, feed and environmental approval by the United States. Work to ensure our products will have appropriate regulatory approvals with other countries continues.

Before a biotech product can be introduced to the market, approval from appropriate governmental agencies is required. Following criteria established by the agencies, DuPont conducts extensive tests on its biotech products. For the approval of HXRW, extensive safety data was provided by Pioneer and Dow AgroSciences LLC to the U.S. Department of Agriculture (USDA), Environmental Protection Agency (EPA), Food and Drug Administration (FDA) and the regulatory systems of other countries. Data on the genes and proteins used to develop the trait, crop characteristics, food and feed composition and potential environmental impacts were compiled over several years and from multiple environments.

The following tests were conducted on HXRW:

Molecular Analysis

Plant genetic material (DNA) from HXRW was analyzed to determine the functional integrity of the introduced genes that confer insect and herbicide resistance (cry34/35 and pat genes). The molecular analysis proved functional integrity by showing that the DNA insert that confers resistance occurred as a simple integration into the plant genome.

Trait Stability

Trait stability and agronomic performance were monitored over multiple generations and environments. Plants of every generation were resistant to the herbicide and to infestation of target insects. Measured agronomic parameters were all within the range of values obtained for conventional corn hybrids.

Trait Specificity

Laboratory, greenhouse and field efficacy studies have demonstrated that Cry34/35 proteins are effective in controlling the larval stages of western, northern and Mexican corn rootworm. Substantial testing has been conducted on non-target organisms including mammals (e.g. rats, mice), birds, fish, earthworms and non-target arthropods (e.g. springtails, ladybird beetles, monarch butterflies, honeybees).  No adverse effects have been observed at environmentally relevant concentrations of the Cry34/35 proteins.

Toxicity and Allergenicity

All proteins used in corn to generate the HXRW trait (Cry34/35 and PAT) are present in soil bacteria. These bacteria are not considered to be pathogens for humans or animals.

The percentage of proteins that are allergenic is very small. Only about 200 of the hundreds of thousands of proteins humans consume in food have been identified as allergens. Cry34, Cry35, and PAT proteins were checked for characteristics typical of known allergenic proteins.  Based on studies that evaluated the source of the trait; amino acid sequence similarity with known allergens; prevalence in food; and biochemical properties of the protein, including in vitro digestibility in simulated gastric fluid (SGF), heat lability, and glycosylation, it was concluded that Cr34, Cry35, and PAT are not likely to be allergens.

While most proteins are not toxic, those that cause adverse effects appear to mediate toxicity act through acute mechanisms of action. No evidence of toxicity was observed in mice following acute exposure to the Cry34 or Cry35 proteins alone or in combination or the PAT protein at exposure levels equivalent to many thousand times the estimated dietary intake of humans.

The lack of adverse effects of HXRW was further supported by a subchronic (90-day) feeding study in rats and a 42-day feeding study in broiler chickens. No adverse effects or diet-related differences were observed in animals consuming HXRW grain compared to animals consuming diets formulated with conventional grain

Substantial Equivalence

The FDA reviews information showing that a biotech crop is equivalent to a non-biotech counterpart that has a history of safe food use. This is known as "substantial equivalence."  » More [.pdf]

Compositional analysis and nutritional assessment of HXRW was conducted by comparing the levels of nutrients including fats, proteins, fiber, minerals, and vitamins in HXRW corn with levels in near isoline and other corn lines.


Herculex Insect Protection technology by Dow AgroSciences and Pioneer Hi-Bred. ®Herculex is a registered trademark of Dow AgroSciences LLC.