RISC is human health risk assessment software tool for performing human health risk assessments for contaminated sites. Fate and transport models are available to estimate receptor point concentrations in indoor and outdoor air and groundwater. A unique feature of RISC5 is its ability to perform a backward risk calculation as well as the conventional forward risk calculation. The backward risk calculation in RISC5 refers to calculating a cleanup level for an input value of risk. RISC can be used to estimate the potential for adverse human health impacts (both carcinogenic and non-carcinogenic) from up to nine exposure pathways. Additional pathways and other non-human health impacts may be considered in future revisions of RISC.
In 1993, BP made a business decision in the U.S. to develop a standardized approach for conducting soil and groundwater risk assessments across all ‘downstream’ activities (service stations through refineries). The rationale was that the company needed to ensure that the latest thinking on fate and transport, exposure, statistical analyses and toxicological criteria were adopted and applied uniformly across its businesses. It would also help ensure that BP spoke with a consistent voice when approaching regulators and the community on this vital issue. Eventually it became clear that a software package containing embedded fate and transport models with intuitive user inputs offered the most convenient and flexible means of implementing this objective. This would enable the process to be readily standardized, communicated and transferred, while still allowing a risk application to be individually tailored to the regulatory regime of the particular business or country. By developing the code in-house, BP would also be able to rapidly adopt new algorithms or approaches (e.g. indoor air models), thus keeping the process evergreen. RISC (previously referred to as BP RISC) Versions 1.0 and 2.0 of the code were released in January, 1994 and August, 1995, respectively, with the former pre-dating the publication of the ASTM standard Risk-Based Corrective Action Applied at Petroleum Release Sites, commonly known as RBCA . Version 3.0, released in September, 1997, was a major upgrade that allowed back-calculations to be performed, i.e. soil and groundwater clean-up targets to be calculated for an input value of acceptable risk.