The RiskMerger tool for demonstrating risk ranking of hazards is a modular system based on ‘Risk Ranger’ system of Ross, T. and Sumner, J. (2002). It makes a semiquantitative assessment, based on expert opinion, with limited data. In contrast to the Ross-Sumner model, not only human health risks are considered, but political and economic risks as well. Therefore, the model elaborated cannot be seen as a pure health risk assessment, but as an evaluation tool with risk manager’s risk-based prioritisation.

The tool was originally coded in a spreadsheet; macros should be enabled. As spreadsheet macros can form a potential risk for your computer it was decided to port the spreadsheet code into an online version. For a copy of this tool, send a request from Mr.Jóźwiak; contact information is given at the bottom of this page.

For the online version you can click its icon .

Structure of the model

In general, the impact of a given hazard is multiplied with the exposure, and then the economic and political risks are added. These three risks are weighted against each other using weighing factors that are to be provided by the user. E.g. use 1, 1, 1 to express an equal weight for all risks. After that, a risk ranking score is calculated for each hazard-matrix pair. The value of the risk ranking score is between 1 and 100, the higher number means higher risk. The ranking score has no absolute meaning, but can be used for comparison with other scenarios.


The model doesn’t calculate with possible additional risk introduced by household food preparation, the consumption quantity, and the effect on the sensitive population (e.g. young, old, pregnant, ill, immunocompromised people or people on special diet). As those factors can only be estimated with a very high uncertainty, those are excluded from the model.

Contact infomation

This model is developed and maintained by

Mr. Ákos Jóźwiak DVM, PhD, hon. prof.
University of Veterinary Medicine
Digital Food Institute, Budapest