​Biosafety worldwide - Historical background

The definition of a GMM/GMO in European legislation

One of the key provisions of the Directives was the definition of a "genetically modified organism" (GMO), which was defined as follows: "An organism in which the genetic material has been altered in a way that does not occur naturally by mating and/or natural recombination" (Article 2 of Directive 90/220/EEC). Directive 90/219/EEC gives a similar definition for the term "genetically modified micro-organism".

The way through which the genetic material is altered to result in a GMM/GMO is specified in an Annex to the Directives via three lists of techniques (see box). Through this approach, the European Union therefore chose to regulate specifically the use of certain genetic modification techniques. Recombinant DNA is listed, as well as other techniques (injection, encapsulation, cell fusion) which at the time were considered to lead to a "non-natural" modification of the genetic material of the host cell.

In contrast, the European Union chose not to regulate the use of other techniques. These latter techniques fell into two categories:
- Firstly, techniques considered as not giving rise to genetic modification in the sense of the Directives (the resulting organisms are therefore not considered to be GMMs/GMOs). Natural transfer processes of genetic material such as conjugation, transduction, or transformation belong to this category;
- Secondly, techniques giving rise to GMMs/GMOs but which are excluded from the application of the Directive. This covers genetic modification techniques that have been traditionally used for various applications and of which it was considered at that time that there was a sufficient history of use in order to consider that the resulting organisms were of no known risk to public health or the environment. For example, GMMs and GMOs obtained by mutagenesis following exposure to ionising radiation or to mutagenic chemical agents were not covered by the Directives and therefore not subject to a risk assessment in the frame of the Directives.​

Genetic modification techniques

Directives 90/219/EEC and 90/220/EEC distinguished 3 categories of techniques in relation to the GMM/GMO definition.​​​

(1) Techniques of genetic modification leading to GMMs/GMOs covered by the Directives (non-exhaustive list):
- recombinant DNA techniques using vector systems (this wording was clarified during the revision of the Directives at the end of the 1990s, nucleic acid recombination techniques being defined as involving the formation of new combinations of genetic material by the insertion of nucleic acid molecules produced by whatever means outside an organism, into any virus, bacterial plasmid or other vector system and their incorporation into a host organism in which they do not naturally occur but in which they are capable of continued propagation);
- techniques involving the direct introduction into an organism of heritable material prepared outside the organism including micro-injection, macro-injection and micro-encapsulation;
- cell fusion (including protoplast fusion) or hybridization techniques where live cells with new combinations of heritable genetic material are formed through the fusion of two or more cells by means of methods that do not occur naturally.

(2) Techniques which are not considered to result in genetic modification, on condition that they do not involve the use of recombinant DNA molecules or GMOs:
- in vitro fertilization;
- conjugation, transduction, transformation or any other natural process;
- polyploidy induction.

(3) Techniques of genetic modification to be excluded from the Directives, on condition that they do not involve the use of GMOs as recipient or parental organisms:
- mutagenesis;
- cell fusion (including protoplast fusion) of plant cells where the resulting organisms can also be produced by traditional breeding methods.
In Directive 90/219/EEC only, the two following techniques are also excluded:
- the construction and use of somatic animal hybridoma cells (e.g. for the production of monoclonal antibodies);
- self-cloning of non-pathogenic naturally occurring micro-organisms which fulfil the criteria of Group I for recipient micro-organisms (the wording "self-cloning" was defined during the revision of the Directive 90/219/EEC in 1998, as consisting in the removal of nucleic acid sequences from a cell of an organism which may or may not be followed by reinsertion of all or part of that nucleic acid (or a synthetic equivalent) with or without prior enzymic or mechanical steps, into cells of the same species or into cells of phylogenetically closely related species which can exchange genetic material by natural physiological processes where the resulting micro-organism is unlikely to cause disease to humans, animals or plants).

As can be seen, the definition of GMM/GMO in the European Directives (and therefore the scope of these Directives) is based on the process of obtaining the organisms, focusing therefore on the methods used (genetic modification techniques) to obtain the GMM/GMO rather than the final product itself. At the same time, other countries such as Canada and the United States opted for different approaches, the characteristics of the organism (the product) or its use being the determining factor in justifying a risk assessment, rather than the technique used to develop the organism.

The GMM/GMO definition set in 1990 at a European level is still used today. However, this definition, and the list of techniques associated with it, remains the focus of intense discussions on a European level.​