This issue of the Journal of Industrial Microbiology contains a compilation of papers presented at the 1992 National Meeting of the Society for Industrial Microbiology in two symposia entitled 'Environmental Assessment of Recombinant DNA Fermentations'. It focuses on three areas of particular interest to industry using Escherichia coli K-12 strains to make recombinant proteins: (i) the current regulatory environment; (ii) plant design; (iii) results from five different companies all of whom are using or planning to use recombinant E. coli in commercial fermentations. The results from all five companies pursuing the questions of environmental fate and the potential for gene transfer in different studies reached the same conclusions. That is, recombinant E. coli K-12 strains and their plasmidless hosts were unable to survive in any environmental microcosm tested. Additionally, there was absolutely no evidence of gene transfer despite the use of highly sensitive techniques to measure such an event. It seems reasonable to conclude that E. coli K-12 strains with recombinant, non-conjugating, poorly mobilizable plasmids do not represent environmental hazards in the event of an accidental release of such microorganisms into the environment.