Verantwoord innoveren

Synthetic biology
Adaptive Risk Assessment
GMO safety

ATOX13 February 2019

Lack of adverse effects in subchronic and chronic toxicity/carcinogenicity studies on the glyphosate-resistant genetically modified maize NK603 in Wistar Han RCC rats

Pablo Steinberg, Hilko van der Voet, Paul W. Goedhart, Gijs Kleter, Esther J. Kok, Maria Pla, Anna Nadal, Dagmar Zeljenková, Radka Aláčová, Júlia Babincová, Eva Rollerová, Soňa Jaďuďová, Anton Kebis, Elena Szabova, Jana Tulinská, Aurélia Líšková, Melinda Takácsová, Miroslava Lehotská Mikušová, Zora Krivošíková, Armin Spök, Monica Racovita, Huib de Vriend, Roger Alison, Clare Alison, Wolfgang Baumgärtner, Kathrin Becker, Charlotte Lempp, Marion Schmicke, Dieter Schrenk, Annette Pöting, Joachim Schiemann, Ralf Wilhelm



In 2012, a controversial study on the long-term toxicity of a Roundup herbicide and the glyphosate-tolerant genetically modified (GM) maize NK603 was published. Thereafter, the European Commission (EC) asked the European Food Safety Authority (EFSA) to provide supplementary guidance on key elements to be considered for a 2-year carcinogenicity trial in rats with whole food/feed if requested in the course of a GMO risk assessment. In this context, the EC-funded G-TwYST research consortium performed two 90-day feeding trials, one with GM maize inclusion rates of 11 and 33% and one with inclusion rates of up to 50%, as well as a combined chronic toxicity/carcinogenicity study with inclusion rates of 11 and 33% by taking into account OECD Guidelines for the testing of chemicals and EFSA recommendations on the safety testing of whole-food/feed in laboratory animals. In all three trials, the NK603 maize, untreated and treated once with Roundup during its cultivation, and the conventional counterpart were tested. The G-TwYST consortium evaluated all significant differences identified between the test groups and the control group, considering equivalences, whether the effects were dose-related and/or accompanied by changes in related parameters including histopathological findings. It is concluded that no adverse effects related to the feeding of the NK603 maize cultivated with or without Roundup for up to two years were observed. Based on the outcome of the subchronic and combined chronic toxicity/carcinogenicity studies, recommendations on the scientific justification and added value of long-term feeding trials in the GM plant risk assessment process are presented.


The open source paper is available online at


​​ Kantoor:
+31 (0)343 51 47 61
+31 (0)6 238 68 017

Diederichslaan 25
3971 PA Driebergen