This relates to the potential for suffering disease or injury that will be tolerated by an individual, group, or society in exchange for the benefits of using a substance or process that will cause such disease or injury.

Acceptability of risk depends on scientific data, social, economic, and political factors, and on the perceived benefits arising from a chemical or process that creates the risk(s) in question.

From the BioTech Dictionary at http://biotech.icmb.utexas.edu/. For further information see the BioTech homenode.