The density of a culture can lead to a risk of exposure to high concentrations of the GMM, particularly in downstream processing operations.

The standard operating procedures of individuals undertaking work with cultured GMMs such as centrifugation or sonication will have a significant impact on the effectiveness of any containment measures employed.

"contained use" shall mean any activity in which micro-organisms are genetically modified or in which such GMMs are cultured, stored, transported, destroyed, disposed of or used in any other way, and for which specific containment measures are used to limit their contact with the general population and the environment;

This Directive shall not apply to the storage, culture, transport, destruction, disposal or use of GMMs which have been placed on the market in accordance with Council Directive 90/220/EEC of 23 April 1990 on the deliberate release into the environment of genetically modified organisms (*) or pursuant to other Community legislation, which provides for a specific environmental risk assessment similar to that laid down in the said Directive, provided that the contained use is in accordance with the conditions, if any, of the consent for placing on the market.