Recommendation: Strengthen the precautionary principle in the risk assessment of genetically modified organisms in the EU through exclusion criteria.

A contribution by Dr. Christoph Then

The precautionary principle, as enshrined in EU Directive 2001/18, can only work if effective measures can actually be taken to protect the environment and human health in cases where this appears necessary. Retrievability (i.e. controllability in time and space) is a crucial prerequisite for this.

“Member states shall ensure, in accordance with the precautionary principle, that all appropriate measures are taken to avoid adverse effects on human health and the environment which might arise from the deliberate release or placing on the market of GMO” (EU Directive 2001/18, Article 1). As soon as evidence emerges for an actual risk to humans and the environment, emergency measures must be taken: “Member states shall ensure that emergency measures, such as suspension or termination of the placing on the market, are taken in the event of a serious risk […]” (EU Directive 2001/18, Article 23). In addition, there is the provision from Article 13 of the directive that marketing authorization may only be granted for ten years. Thereafter, the approval must be reviewed again on the basis of monitoring. If the genetically modified organism loses its approval, it must be removed from the environment again.

The release or placing on the market of genetically modified organisms whose spread cannot be controlled is fundamentally in conflict with these provisions. If a GMO can no longer be retrieved from the environment, the enacting of the precautionary principle becomes impossible.

In this context, the GeneTip project, funded by the German Federal Ministry of Education and Research (BMBF), was the first research project in Germany to address the prospective technology assessment of gene drive organisms. [1]  One result of the project is the recommendation to introduce a new central mechanism for the risk assessment of GMO: the designation and definition of so-called reasons for concern (in simple terms, factually justified risks). Such reasons for concern are often identifiable at an early stage of research and development and could lead to the characterization of a GMO as “of particular concern”. To this end, the authors propose, among others, the following criteria for the identification of reasons for concern:

  • Impossibility of making reliable forecasts
  • Interventions in systems that are particularly critical for human health
  • Interference with ecological systems that are pre-stressed or have tipping points
  • Lack of technical maturity and reliability
  • Particularly wide reach, to the point of global and irreversible spread of GMO
  • The ability to spread in natural populations

According to the report of the GeneTip project, a characterization as a ‘GMO or construct of very high concern’ could lead to the same consequences as stipulated for substances regulated under  the EU chemicals legislation REACH and the EU pesticides legislation, respectively. Here, the estimation of the spatial-temporal complexity or controllability plays an important role.

The REACH regulation states that “experience at international level shows that substances with persistent, bioaccumulative and toxic properties or with very persistent and very bioaccumulative properties are of particular concern.”[2] Therefore, REACH established appropriate criteria to define persistent, bioaccumulative and toxic substances, as well as substances that are particularly bioaccumulative and persistent.

The EU regulation on the authorization of pesticides integrates these criteria for POP (persistent organic pollutant), PBT (persistent, bioaccumulative, toxic) and vPvB (very persistent, very bioaccumulative) into the decision-making process as exclusion criteria, which mean that authorization can generally be refused and the authorization process is not continued.[3] The decisive factor is not only the toxicity of a substance, but also its behavior and fate in the environment. If a substance is classified as vPvB, it cannot be approved under this EU regulation, even if long-term damage has not been proven.

According to the final report of GeneTip, such cut-off criteria could also be helpful in the approval of GMO and gene drive organisms. If genetically modified organisms escape spatiotemporal controllability because they can replicate in natural populations without effective control of their persistence and spread, a sufficiently reliable risk assessment would not be possible. The approval process cannot continue and a release of the GMO cannot be authorized.

The results of GeneTip were taken into account by the expert group (AHTEG) advising the Conference of the Parties to the UN Convention on Biological Diversity. Among other things, unforeseen effects that occur only after several generations are named as a specific challenge for risk assessment.[4] In contrast, the European Food Safety Authority (EFSA) largely ignores these challenges in its report submitted in November 2020.

Dr. Christoph Then is head of the Institute for Independent Impact Assessment in Biotechnology (TestBiotech) and co-author of the GeneTip project. Testbiotech is concerned with impact assessment in the field of biotechnology, calls for and promotes independent research, examines ethical as well as economic consequences, and tests risks to humans and the environment. Testbiotech provides industry-independent expertise and thus aims to strengthen the decision-making competence of society.







[1] 121 Gene Tip website (without year). Testbiotech e.V. Institute for Independent Impact Assessment of Biotechnology. BioTip pilot study: Gene Drives at Tipping Points – Precautionary Technology Assessment and Governance of New Approaches to Genetically Modified Animal and Plant Populations. Online: [last accessed Dec. 07, 2020].

[2] EUR-Lex Website (2006). Publications Office of the European Union. Regulation (EC) No 1907/2006 of the European Parliament and of the Council of 18 December 2006 concerning the Registration, Evaluation, Authorisation and Restriction of Chemicals (REACH), establishing a European Chemicals Agency, amending Directive 1999/45/EC and repealing Council Regulation (EEC) No 793/93 and Commission Regulation (EC) No 1488/94 as well as Council Directive 76/769/EEC and Commission Directives 91/155/EEC, 93/67/EEC, 93/105/EC and 2000/21/EC. Online: [last accessed: 07.12.2020]

[3]     EUR-Lex website (2009). Publications Office of the European Union. Regulation (EC) No 1107/2009 of the European Parliament and of the Council of 21 October 2009 concerning the placing of plant protection products on the market and repealing Council Directives 79/117/EEC and 91/414/EEC. Online: [last accessed Dec. 07, 2020].

[4] Convention on Biological Diversity. Ad Hoc Technical Expert Group on Risk Assessment (2020). Report of the Ad Hoc Technical Expert Group on Risk Assessment. CBD/CP/RA/AHTEG/2020/1/5. 15. April 2020, Montreal, Canada. Online: