The US Nuclear Regulatory Commission uses quantitative radiogenic cancer risk information in a number of official areas. In this article, the authors describe two specific areas where quantitative cancer risk information is used: (1) the system of radiation protection for workers and the public, and (2) the performance of value-impact analysis (i.e., cost–benefit analysis) in the review of imposing new regulations on the industry. The authors write that two main factors have led to a change in the recommended occupational dose limit. First, the International Commission on Radiological Protection (ICRP) moved away from comparisons with safe industries, instead basing its assessment on cancer risk resulting from a lifetime of radiation exposure. The second factor is that additional epidemiological data have accumulated since 1977 and, combined with changes in the methods used to analyze this data, have resulted in a reassessment of the risk-per-unit radiation dose. The ICRP now recommends an annual occupational dose limit of .020 sievert. There was no corresponding change in the recommended dose limit for members of the public. Currently, the NRC is evaluating these changes and considering revising its regulations accordingly. Nonetheless, the authors write, dose limits play a very small role in modern radiation protection practices, the emphasis being on optimizing situations involving radiation exposure, with the result that most licensed facilities operate at annual doses to workers and members of the public that are well below any applicable limit.