Safety Testing of Transgenic Foods


Progress Working Group 1: Safety Testing of Transgenic Foods

The goal for WG1 defined at the First Plenary Meeting in Wageningen (May 12-13, 2000) is the establishment of guidelines on appropriate methodologies for the identification/evaluation of specific hazards of GM foods. Particular attention will be paid to the assessment of genetically modified crops with complex crop traits, such as crops with altered nutritional characteristics. The critical evaluation of assessment methodologies will be the basis for providing more detailed guidelines on safety testing strategies for different product categories.

At the Second Plenary Meeting in Copenhagen (October 13-14, 2000) a set of deliverables was defined, an action plan was drawn up, and miscellaneous other matters were addressed, including the need for co-ordination with work on methodologies for food safety assessment in progress.


Three background documents will be drafted that will serve as a basis for the main deliverables of WG1. First, a paper will be drafted outlining the use and the limits of the concept of substantial equivalence. The paper will be partly based on conclusions of the FAO/WHO consultation in June 2000, and will discuss whether and how substantial equivalence could be used as a tool for safety evaluation with regard to the biological and toxicological significance of unintended effects (in collaboration with WG2). Secondly, a paper will be drafted that provides definitions of terms such as hazard identification, hazard characterisation and risk assessment and that provides a description of approaches to the identification of hazards of GM foods. This document will also address which hazards should be considered most relevant to which product categories (i.e. herbicide-tolerant crops, crops with altered nutritional characteristics, etc.). Thirdly, a brief overview on currently used methodologies for safety testing will be provided and their adequacy for the different hazard evaluations will be discussed. This should give a preliminary view on how to organise a full safety evaluation study in a most coherent and complete approach optimising the different testings to be performed.

The main deliverable of the WG1 will be a document that provides an overview of potential and perceived hazards of GM crops and of methodologies for their identification and characterisation.

Currently used methodologies will be critically evaluated to determine their adequacy for assessment of GM crops with more complex traits. The state of the art of the development of novel technologies will also be reviewed, including a review of research conducted under the SAFOTEST project. Gaps where new or updated methodologies are required will be identified. The three background documents will be used for integration into the main document where appropriate.

The following structure was proposed for the main document:

For each potential or perceived hazard, the following aspects will be addressed:

  • Is it a real concern ? What is the probability that this type of hazard will manifest itself?
  • Does the concern relate to:
  • An introduced substance / protein?
  • The whole GM food?
  • All of the above?
  • What methodologies are available or under development to identify the hazard in question?
  • What confidence do we have that in the ability of those methodologies to predict the particular hazard?
  • Potential of the methods to characterise the hazard, in particular with respect to chronic effects.


Hazards fall into three categories microbiological hazards, nutritional hazards (e.g. imbalances) and toxicological hazards. A preliminary list of toxicological hazards was drawn up:

General Specific
  • Acute toxicity
  • Genetic toxicity
  • Sub acute toxicity
  • Allergenicity
  • Chronic toxicity
  • Immunotoxicology
  • Neurotoxicity
  • Gastrointestinal toxicity
  • Special organ toxicity
  • Endocrine toxicity / endocrine disruption
  • Reproductive and developmental toxicity
  • Carcinogenicity


Possible alteration of a biosynthetic/metabolic pathway and the need for tolerance studies were also mentioned.

It will need to be determined at the next meeting whether, if and how to use case studies in the document.

A document that provides an overview on available tools for the evaluation of potential hazards associated with GM crops will serve three main purposes. First, it serves as a guideline for industry and regulators on appropriate methodologies used in the risk assessment on a case-by-case basis. Secondly, recommendations will be provided on research priorities for the development of future methodologies for hazard identification and characterisation and risk assessment of GM crops. Thirdly, a simplified version of the document for broad dissemination will contribute to inform a broader audience on past present and future research on the development of tools for the safety assessment of GM crops. This will hopefully contribute to provide assurance that some immediate public concerns, such as on long-term effects of GM crops, are being addressed.