The Convention on Biological Diversity opens the possibility to negotiate a legally binding Biosafety Protocol to assess and minimize risks in the field of transboundary transfer, handling, and use of organisms modified by genetic engineering. Two principles— the Precautionary Principle and the Principle of Familiarity—guiding the risk assessment as basis of import decisions on such organisms are discussed. Developing and European industrialized countries favor the Precautionary Principle. The U.S., Australia, Japan, and some others call for the Principle of Familiarity. These (...) two principles exhibit opposite effects on scientific progress in general and on scientific methodology of risk assessment in particular. With the example of risk assessment by the U.S. company Monsanto discussed below, it could be illustrated that the Principle of Familiarity opens the way for superficial evaluations based on citing arbitrary references while the Precautionary Principle is an incentive for developing and applying sound methodology in experimental risk assessment. on the transboundary transfer of such LMOs, for example, on the international exchange of and trade with transgenic seeds, grains, animals, or bacteria. The negotiations are based on Articles 19.3 and 8(g) of the Convention on Biological Diversity, elaborated during the Earth Summit in Rio de Janeiro, Brazil, in 1992, and on Decision II/5 of the Second Conference of the Parties to this Convention in Jakarta, Indonesia, in 1995 (see the appendix; for more documents, see www.biodiv.org). Until the Fourth Conference of the Parties in 1998, 172 states ratified this convention. This conference decided to finish the Biosafety Protocol in February 1999. In 1998, transgenic crops were allowed to be planted in eight (75%) countries of the world. As the country with the largest acreage of transgenic crops and as the main trader of LMOs, the United States cannot become a member of the protocol until it has ratified the Convention on Biological Diversity. (shrink)