Genetically Modified Organisms

What is EFSA’s role in the risk assessment of GMOs?

1. How does EFSA carry out GMO risk assessments?

EFSA carries out the risk assessment of GMOs in the European Union. EU Member States participate throughout the risk assessment process while EFSA’s GMO Panel is responsible for preparing and adopting the GMO risk assessments. Based on the GMO Panel’s risk assessment, EU Member States and the European Commission decide on GMO authorisation applications. Whilst EFSA provides a risk assessment, EU risk managers also take into account other considerations in deciding whether or not to authorize a GMO. EFSA has published a factsheet which explains EFSA’s risk assessment role within the EU legislative framework

Each application received by the EFSA GMO Panel is subject to a thorough review by EFSA’s GMO Panel which has 21 independent scientific experts. The Panel approaches each GMO risk assessment on a case-by-case basis. There is no presumption of safety for any GMO, as each GMO is unique and must be assessed individually to ensure that it poses no risk to human or animal health and the environment. The Panel follows the framework laid down in the EC Directive and Regulations which are reflected in EFSA’s guidance documents, such as the Guidance document for the risk assessment of genetically modified plants and derived food and feed.

2. What does EFSA consider in its risk assessments?
In GMO risk assessment, a comparative assessment is made between the GM crop plant and its conventional crop counterpart to determine if the GM plant, such as GM maize, is as safe as its conventional non-GM counterpart (i.e. maize from conventional breeding).

The majority of GMO applications cover the import and processing of GMOs and/or GM products derived from these. Applications for the cultivation of GMOs cover approximately 15 % of the applications under the EC Regulation 1829/2003 (for more information, see next question).

Each of the following elements is considered for all applications during the risk assessment process:

  • the molecular characterisation of the GM product, taking into account the characteristics of the donor and recipient organism;
  • the compositional, nutritional, and agronomic characteristics of the GM product; 
  • the potential toxicity and allergenicity of the GM product; 
  • the potential environmental impact following a deliberate release of the GM product and taking into account its intended uses either for import, processing or cultivation.

3. What type of applications does EFSA examine?
GMOs can be notified for the following uses: for import; for import and processing; for food, feed and industrial use and/or cultivation. Some GMO applications focus on the use of a product derived from a GM plant to be imported to the EU. The EFSA GMO Panel takes into account this scope and the intended uses of the GM product when performing the risk assessment.

The scope of a GMO application can cover one or more of the following categories (under Regulation 1829/2003):


  • GM plants for food use 
  • Food containing or consisting of GM plants 
  • Food produced from GM plants or containing ingredients produced from GM plants


  • GM plants for feed use 
  • Feed containing or consisting of GM plants 
  • Feed produced from GM plants

OR GM PLANTS FOR ENVIRONMENTAL RELEASE (under Part C of Directive 2001/18/EC) 

  • Import and processing of GM plants 
  • Seeds and plant propagating material for cultivation in Europe

If authorisation is granted by the European Commission and the Member States, the final authorisation for the GM product is restricted to the intended uses of that GM product notified by the applicant and evaluated by EFSA.

Monitoring plans also need to be in line with the specific intended uses of that GM product.

4. What type of data is involved?
As required by Regulation (EC) No 1829/2003, EFSA has published detailed guidance on the type of data that applicants are required to include in any GMO application, as well as the way it should be prepared and presented. EFSA developed this guidance in open consultation with stakeholders and interested parties. GMO applicants need to follow this guidance to enable EFSA’s GMO Panel to assess the safety and the environmental impact of a GMO.

EFSA has issued the following scientific documents:

The guidance documents set out what the GMO panel requires in terms of data and quality of data, including the tests to be carried out on aspects, such as molecular characterisation, toxicity, allergenicity and the environmental impact of the GMO.

In addition, the 21 members of the GMO Panel have a wide degree and breadth of experience in assessing GMOs and extensive knowledge of the latest scientific developments and information in the GMO area. Collectively the GMO Panel members have a significant knowledge of relevant studies and data in the GMO field.

5. Do the same tests have to be carried out on each GMO?
Owing to the individual nature and traits of each GMO, the type of tests needed to assess safety often vary according to the particular type of GMO being tested and the comparative assessment between the GMO and its non-GM counterpart. Through its guidance, EFSA’s GMO Panel applies a case-by-case approach treating each application as unique. Therefore, the guidance is not 100 % prescriptive to specific study protocols and does not stipulate a mandatory list of exactly which tests should be done and under which precise parameters.

However, fixed test protocols are requested especially for scientific issues where harmonization in tests is possible and valid test methods are agreed upon by international risk assessment bodies – for instance on the testing of chemical substances. If the applicant proposes changes to these test protocols, it has to justify how these changes can serve the same purpose and deliver the necessary data.

Any study carried out on the GMO and submitted to EFSA in the risk assessment application must comply with the OECD principles of Good Laboratory Practice (GLP) where applicable and be accompanied by a formal statement of Quality Assurance. The data supplied is often prepared by independent private (contracted) laboratories on behalf of the applicant, operating according to international laboratory standards, such as GLP, Good Manufacturing Practice (GMP) and International Organisation for Standardisation (ISO).

6. What happens if the data provided is not sufficient or is incomplete?

When the data received from the applicant is insufficient for EFSA’s GMO Panel to make a full risk assessment, the applicant is required to provide the missing data before the GMO Panel proceeds with its evaluation. To date, this has happened in 95 % of the cases.

The 21 members of the GMO Panel have a wide degree and breadth of experience in assessing GMOs and extensive knowledge of the latest scientific developments and information in the GMO area. They effectively “pool” their knowledge on all the GMO scientific areas covered by the Panel. As detailed in the EFSA GMO factsheet, Member States are also actively invited to give scientific input to each individual application through the EFSAnet extranet on-line application which was specifically developed for Member States so that they could provide input and participate in the risk assessment process.

7. Why does EFSA not carry out its own studies?

Under present EU legislation, the GMO applicant has the responsibility to demonstrate the safety of the GM product in question and is obliged to present a full application prior to evaluation. This application must contain all of the necessary human/animal safety and environmental impact studies, according to the rules set by European legislation, to allow the European authorities to carry out a risk assessment. According to EU rules, the cost of these studies must be borne by the applicant which has a commercial interest in obtaining an approval. It is not foreseen that EFSA carries out such studies. For the GMOs that EFSA’s GMO Panel has evaluated thus far, when there have been any doubts about the data presented by the applicant, the Panel has required the applicant to provide further data or information before delivering its final risk assessment.

8. How long does it take for EFSA to carry out a GMO risk assessment?
Upon receipt of a new application EFSA has 6 weeks to check for completeness of the application dossier and, if complete, the application is declared valid.

Regulation (EC) No 1829/2003 stipulates that EFSA must endeavour to respect a time limit of 6 months to deliver its overall opinion on a valid application. One component of the overall opinion is the GMO Panel’s risk assessment opinion. Whenever EFSA seeks supplementary information from the applicant, this 6 months time limit is interrupted and the “stop watch” is stopped. When the additional information is considered sufficient, the “stop watch” is started again. Hence the total time period taken to carry out the risk assessment is variable and can range from 4 up to 24 months depending on the time requested by the applicant to submit the additional information.

In addition other issues can interrupt the legal time limit of 6 months, such as the need for additional information by the European Commission’s Joint Research Centre which is responsible for the validation of the detection method used by the applicant for the GMO.

After EFSA has published its risk assessment, other information, such as the Post-Market Environmental Monitoring Plan and Member State comments, is annexed so that EFSA can finalize its ”overall opinion”, according to the legislation. Following publication of the “overall opinion”, the European Commission has 3 months to submit a draft decision to the Standing Committee on the Food Chain and Animal Health made up of representatives of all EU Member states who have to vote on the GMO authorisation. The comitology procedure applies for GMO authorisations and its timeframe is variable.

An authorisation for a certain GMO product and its intended uses is given for a limited time of 10 years, after which period the applicant must apply for a renewal of Authorisation to continue to place the GM product on the EU market. This renewal is dependent on EFSA’s GMO Panel carrying out a risk assessment of the GMO after 10 years of being on the market.

9. What is EFSA’s role in the renewal of GMO authorisations?
GMO authorisations are granted by the European Commission and Member States for a period of 10 years. Applicants wishing to extend this period can apply for a renewal. EFSA’s GMO Panel evaluates renewal applications following a process similar to the one for new applications. Renewal applications need to include any new information that has become available during the authorisation period regarding safety for humans, animals and the environment. This includes a review of any peer-reviewed data on the GMO which could be relevant to its safety, a report on the areas and quantity of production, the main uses in Europe and information on human and animal exposure; updated information on allergenicity and toxicology; a report on the stability of the GM trait and detection methods, and a report on any unintended or unanticipated effects. Where cultivation is involved, applicants also have to submit reports on cultivation locations, areas, volumes, stewardship and other information on agricultural practices; the impact on agricultural surrounding environments; interactions that may take place with other plants, and an environmental monitoring report. Applicants have to provide justification if they do not submit any element of the data set required by EFSA. See the Guidance document for the renewal of authorisations of existing GMO products.

10. Can the public access these GMO applications?
All EFSA opinions and the summaries of the GMO application are published and made available on the EFSA website. In addition, according to EU rules, the public may request access to the full documentation submitted by applicants and third parties to EFSA. Normally, access is allowed to such documentation except where information is claimed to be confidential by the applicant. If the applicant claims confidentiality to parts of an application, it is up to the European Commission or a Member State to decide whether the claim for confidentiality is justified or not.

Who is involved in assessing GMOs?

11. How are the scientific experts of EFSA selected?
Independence and scientific excellence are the cornerstone of EFSA’s work and both are critical to building and maintaining public confidence in European risk assessment. EFSA seeks to select the best scientific experts in their scientific field for its Scientific Panels and Scientific Committee. Their biographies are publicly available on the EFSA website. See the decision of the Executive Director concerning the selection of members of the Scientific Committee, Scientific Panels and external experts

Members of EFSA’s Panels undertake to act independently. The independence of scientific experts and all those involved in the activities of EFSA is ensured by a mandatory Declaration of Commitment of independence and a Declaration of Interests (DoI). These declarations are made annually and are also publicly available on the EFSA website. In addition to these annual declarations, all experts involved in EFSA activities are required to declare at each meeting any interests which might be considered prejudicial to their independence in relation to the items on the agenda. EFSA recognizes that high quality of scientific expertise is by nature based on prior experience. Hence, having an interest does not necessarily mean having a conflict of interest. EFSA’s policy on DoIs is not to ban or sanction the holding of interests by individuals operating in the sphere of EFSA but to facilitate in a transparent and consistent manner the handling of situations where potential conflicts may arise.

EFSA monitors closely the Declarations of Interests of all its scientists and is vigilant so that members of all its Panels fully comply with the requirements of independence fundamental to their role. In addition to this, the opinion of the GMO Panel, made up of 21 members, is a collective position where the Panel works towards consensus, with the possibility to express minority views.

Minority views may be expressed and are recorded, together with the supporting argumentation, as is laid down in Article 19 of the EFSA Management Board decision concerning the establishment and operations of the Scientific Committee and Panels

12. How many people work on GMO risk assessment at EFSA?
EFSA’s GMO risk assessment work is carried out by the GMO Panel of scientific experts with experience in a wide range of GMO scientific disciplines: biochemistry, food and environmental food microbiology, soil microbiology, molecular biology, genetics, toxicology, animal pathology, immunology, biotechnology, food sciences, ecology, plant biology, agronomy, entomology and statistics. EFSA’s Founding Regulation foresees a maximum of 21 members for each of EFSA’s Scientific Panels. EFSA's GMO Panel is made up of 21 scientific experts who are responsible for evaluating the scientific information, discussing its content and deciding on the final risk assessment opinion. In order to facilitate and prepare their work, Panel members are assisted by:

  • Over 40 additional experts presently working with the GMO Panel with specialisation in areas, such as the environment, allergenicity and statistics. The Declarations of Interests (DoIs) of these experts are also published on the EFSA website. These experts usually co-operate with the GMO Panel as a member of a special Working Group, depending on the particular expertise needed to support the Panel in carrying out its activities. See EFSA's Expert database
  • An EFSA scientific secretariat presently consisting of 11 scientists and 4 support staff.
  • EFSA’s Scientific Co-operation and Assistance Directorate provides support to all Panels on specific scientific aspects, such as statistics and data collection.
  • EFSA’s Scientific Committee which includes the chairpersons of EFSA’s 10 Panels, including the Chair of the GMO Panel, provides guidance and opinions on horizontal risk assessment issues. For example on risk/benefit analysis and transparency.
  • When necessary, EFSA’s Advisory Forum which brings together national food safety authorities of all EU Member States is consulted on specific issues. On 13th November 2007, there was a meeting of the EFSA Advisory Forum on GMO risk assessment, organised in order to share and discuss details of respective national GMO risk assessment approaches, identify common approaches and possible diverging procedures among Member States or between Member States and EFSA on defined elements of GMO risk assessment, and to consider priorities for future risk assessment developments.

These combined scientific resources provide EFSA with a strong and flexible scientific capacity for dealing with the breadth of scientific issues which are typically addressed when assessing a GMO application for many different types of GMO, such as plants or microorganisms, and which are relevant when developing further risk assessment methods.

Does the European Food Safety Authority also assess environmental issues?

13. How does EFSA take account of long-term effects for human health and the environment?
The assessment of potential long-term effects is one of the fundamental pillars of the GMO regulatory framework (Directive 2001/18/EC and Regulation (EC) No 1829/2003) and is therefore a prime focus of risk assessment work performed by Member States and EFSA. Applicants of GMO applications are obliged to provide adequate data in their application to allow assessment of the potential long-term adverse effects of the GMO on both human/animal health and the environment.

EFSA’s GMO Panel evaluates the data provided by the applicant and provides a safety assessment opinion. The data provided by the applicant is based on extensive molecular characterisation, compositional analysis, and in silico, in vitro and in vivo testing in order to provide sufficient assurance on the safety of GM food/feed. Short-, mid- and long-term effects of a GM crop on non-target organisms, soil micro-organisms, bio-geochemical processes, or due to gene transfer, or due to consumption are considered and assessed by the GMO Panel. Following the results of these risk assessment steps, and when there are specific indications, additional long-term studies are considered in certain cases. Post market monitoring of GM foods/feed may also be considered.

When not identified during the Environmental Risk Assessment, potential long-term effects to ecosystems can be managed or further monitored by national authorities through the Post Market Environmental Monitoring (PMEM) activities, which are obligatory for each GM product.

In addition, EFSA continues to develop its environmental risk assessment approaches and during 2008-2009 will work on specific environmental mandates. The Directorate-General for the Environment of the European Commission has asked EFSA to further update the GMO Panel’s guidance document for the risk assessment of genetically modified plants and derived food and feed with regard to potential long-term environmental effects and the development of criteria for setting up field trials to assess environmental impact. EFSA has also begun a self-task activity on so-called “Non-target Organisms”. This will consist of further developing guidance for assessing potential adverse effects that GM plants might have on non-target organisms, such as insects (e.g. butterflies, beetles) not targeted by the specific insect-resistant trait expressed by the GM plant.

Some examples of data requirements on the applicant are:

  • Animal feeding trials with the whole GM plant are requested in cases where the above comparative assessment indicates substantial differences between the GM plant and its conventional counterpart. 90-day feeding studies in rats are accurate enough to predict the potential effects of compounds after chronic exposure. A special Working Group of the GMO Panel has scrutinized the results of animal studies used to test the potential short and long-term toxicity of GMOs. The majority of the experiments analyzed did not indicate clinical effects or abnormalities in organs or tissues of exposed animals. For further information, see EFSA’s report on animal feeding trials
  • In cases where indications from the subchronic study or other information on whole GM plant-derived food and feed suggest the potential for reproductive, developmental or chronic toxicity, the performance of such testing should be considered.
  • As a mandatory part of the application and according to the outcomes of the risk assessment, the applicants must also describe the post market environmental monitoring plan showing how the GM product shall be monitored in the environment (and in the food and feed chain) once allowed on the market. Such monitoring plans include annual and longer term reporting to the risk manager. Annual reports must include information on any possible adverse environmental impact or unanticipated adverse effects of GM products. These monitoring plans allow the risk manager to closely monitor the GM product after it comes onto the market, so that unanticipated effects can be detected during the first 10-year authorisation period and appropriate action taken, if needed.
  • After an initial 10-year authorisation period, each GM product must be re-evaluated by EFSA’s GMO Panel before the European Commission and Member States can consider its re-authorisation. During re-evaluation, the Panel takes into account all available information from post market monitoring plans.

14. How does EFSA assess potential impact on biodiversity?
Around 15 % of GMO applications under Regulation (EC) No 1829/2003 are for cultivation and need to be evaluated for their potential impact on biodiversity. The term biodiversity is broad and covers many different aspects.

14.1 Does the genetic modification in a plant change the impact on biodiversity?
EFSA’s GMO Panel checks whether the genetic modification can affect a plant’s impact on biodiversity. Concerns about the effects of GMOs on biological diversity through the deliberate release into the environment of GM crops (i.e. for field-testing or commercial growing) have been anticipated and addressed by Directive 2001/18/EC. These concerns are mainly related to: (1) the potential spread of the GM crop outside the field (for example through invasiveness or enhanced competition), (2) the potential transfer of the inserted gene (and its trait) to other organisms, for example by pollen, (3) the potential impacts on non-target species (i.e. species which are not considered to be a pest to the crop, such as specific insects or birds), and (4) the potential impacts on soil bacteria or soil composition. All these aspects must, as foreseen in EU GMO legislation, be considered during the risk assessment of applications intended for cultivation in the EU.

The GMO Panel also evaluates these elements when considering the potential consequences of seed spillage during transport for applications for GMO import and processing. Applicants are obliged to provide the necessary data to evaluate these aspects which are thoroughly analyzed and taken into consideration before conclusions on the safety of GM crops are made.

14.2. What is the baseline for assessing the impact on biodiversity?
The potential changes of the genetic modification on the impact of the plant on the environment is assessed. A comparative risk assessment is performed, comparing the GM crop plant with its conventional counterpart crop. As a consequence, the risk assessment can give conclusions whether or not the GM plant (e.g. GM maize) is as safe as its conventional non-GM counterpart (e.g. maize from conventional breeding from which the GM maize is derived).

Issues related to the intensification of agriculture and agricultural practices (such as the average farm size in Europe, the cultivars that are used, monocultures) fall outside the remit of EFSA as these are not related to the safety of GM plants.

15. What about the issue of coexistence with conventional crops?
Coexistence aims at ensuring that all crop productions develop side-by-side, without excluding any agricultural options. The coexistence of GM and non-GM plants is envisaged through coexistence measures laid down by the European Commission and implemented by each Member State. The underlying principles of coexistence are of economic nature (free choice of the farmer, free choice of consumers) and are not related as such to the safety of the genetic modification. Aspects related to coexistence therefore fall outside the risk assessment remit of EFSA and are the responsibility of Member States.

16. How does EFSA deal with the Cartagena Protocol on Biosafety, under the convention of Biological Diversity?
The Cartagena Protocol was created in 2000 to protect biodiversity from any potential harm posed by genetically modified (GM) organisms. The objective of this first Protocol is to contribute to the safe transfer, handling and use of living modified organisms (LMOs) -- such as genetically engineered plants, animals, and microbes -- that cross international borders. This Biosafety Protocol is also intended to avoid adverse effects on the conservation and sustainable use of biodiversity. This is to be ensured in the framework of continuous world food trade.

In EU legislation concerning GMOs, the Cartagena Protocol has been taken into account: by law the applicants are required to provide all the data cited in this Protocol as important to assure compliance to the protocol. EFSA publishes this information as part of the overall opinion for the risk managers.

What about new developments, uncertainties and other challenging issues?

17. How does EFSA keep its risk assessments at the forefront of science?
In addition to carrying out product-specific risk assessments based on GMO applications, EFSA’s GMO Panel also initiates its own work (“self-tasking activities”) in order to stay at the forefront of new scientific developments and to further develop GMO risk assessment approaches.

For example, EFSA has provided five guidance documents describing in detail the studies and information applicants need to provide for:

  • 1. GM plants and derived food and feed
  • 2. GM microorganisms and their derived products intended for food and feed use
  • 3. Renewal of authorisations of existing GMO products
  • 4. GM plants containing stacked transformation events
  • 5. Post-Market Environmental Monitoring (PMEM)

These guidance documents are updated as science evolves and the work of other self-task activities is finished. For example, the plant guidance document will be updated to take into account new content from the recently finished work on animal feeding trials. At present, EFSA is carrying out self-task work on topics such as guidance for the risk assessment of GM plants developed for non-food/feed purposes (e.g. phytoremediation, production of medicinal products etc); guidance for the assessment of environmental impact and, in particular, potential impacts of GMO plants on non-target organisms; allergenicity assessment of GM plants; and statistics in comparative assessment of GMOs.

18. What about uncertainties and assumptions?
It is a general fact that for any new food/feed product, as for any conventional food/feed products, zero risk does not exist, as there is always some uncertainty. It is up to EFSA to investigate and to report on any uncertainties in its risk assessments so that risk managers can consider these in  their decision-making. Scientific assumptions are frequently used across the full spectrum of risk assessment. In assessing risks, all of EFSA’s Scientific Panels, at some time, will have used scientific tests to extrapolate potential effects in humans. A series of scientific assumptions of different risk scenarios is usually needed in order to quantify or qualify those potential risks.

19. Why has EFSA only issued favourable opinions on GMOs?
EFSA’s GMO Panel scrutinises each application according to extensive criteria laid down in EFSA’s GMO guidance documents. To date, GMO applications received by EFSA have been of a generally high scientific standard. Nevertheless, in 95 % of the cases, the GMO Panel has asked the applicant to supply more information in order to be able to carry out a full risk assessment. EU legislation foresees that EFSA can go back to applicants to request additional information or additional studies, when necessary. When this occurs the “clock is stopped” and EFSA is obliged to allow the applicant the opportunity to come back with more information. Applicants can then come back with additional information or studies, as requested by EFSA, so that EFSA’s GMO Panel can continue and finalize its evaluation. In a few cases, applications have been withdrawn by applicants.

EFSA does not authorise GMOs. EFSA provides science-based risk assessments to the European Commission and EU Member States who take these into account, along with other factors, when deciding on the authorization of GMOs.

20. Why does EFSA keep getting asked to look again at its risk assessments?
The European Commission and Member States can call on EFSA's expertise when they require scientific advice on food safety issues. They can do this regarding issues that EFSA has already examined, by asking EFSA to evaluate new scientific data or to further develop certain scientific aspects of its previous opinions. This has happened with a number of GMO applications where the Commission and/or Member States have asked EFSA to look again at certain aspects of its scientific advice. EFSA can also be asked to review its previous advice on a GMO if a Member State invokes legal safeguard measures to prohibit its cultivation or use on their territory. Under the European GMO legal framework, Member States may invoke the safeguard clause if justified by relevant scientific evidence. EFSA can be called on by the European Commission to assess this scientific evidence in relation to a GMO it has already evaluated.

21. What is EFSA’s position on the use of antibiotic resistance marker genes in some GM plants?
Marker genes encoding resistance to specific antibiotics may be used in genetic modification to help identify GM cells among the untransformed cells.

In June 2009 EFSA published a consolidated overview on the use of antibiotic resistant marker genes in GM plants, including a joint scientific opinion by the GMO and BIOHAZ Panels. The Panels concluded that, according to information currently available, adverse effects on human health and the environment resulting from the transfer of the two antibiotic resistance marker genes, nptII and aadA, from GM plants to bacteria, associated with use of GM plants, are unlikely. Uncertainties in this opinion are due to limitations related, among others, to sampling and detection, as well as challenges in estimating exposure levels and the inability to assign transferable resistance genes to a defined source. Two members of the BIOHAZ Panel expressed minority opinions concerning the possibility of adverse effects of antibiotic resistance marker genes on human health and the environment.

In another opinion, the GMO Panel reviewed its previous assessments of individual GM plants containing ARMG taking into account the findings and conclusions of the joint opinion of the GMO and BIOHAZ Panels. The GMO Panel concluded that its previous risk assessments on the use of the nptII marker gene in GM plants are consistent with the risk assessment strategy described in the joint opinion and that no new scientific evidence has become available that would prompt it to change its previous opinions on these GM plants.

Following the adoption of the joint opinion of the GMO and BIOHAZ Panels, EFSA asked the panels to consider whether the minority opinions required any clarification of the joint opinion or additional scientific work. The Panel chairs responded that the minority opinions had been extensively considered during the preparation of the joint opinion and no further clarification or scientific work were needed at this time.

[1] EFSA’s GMO Panel may accept non GLP studies provided full assurance is provided that the quality of the study is of an equivalent standard.