In my previous paper, I discussed the U.S. statute, the Toxic Substances Control Act (TSCA), which has the so-called "risk-based" structure. This time, I focused on the upper system which traversed statutes, for instance, a control by the Executive Office, and extracted the characteristics of the system. The most notable features were the regulatory peer-review and the concept of the "scientific integrity". I attempted to contrive the legal significance of the risk assessment, by analyzing the regulatory peer-review and the concept of the "scientific integrity". Moreover, I discussed the relationship between the risk assessment and the administrative discretion using the concepts in "Science, Technology and Society (STS)", for example, "science in operation". In conclusion, there was considerably limited discretion for the administrative agencies on risk assessment.