The final component of the risk assessment is the risk characterization. The risk characterization integrates the information from the exposure and toxicity analysis to derive a quantitative estimate of human health risk.
This is normally accomplished by calculating an exposure ratio called a Hazard Quotient (HQ) for threshold contaminants or an Incremental Life-time Cancer Risk (ILCR) for non-threshold contaminants.
If unacceptable risks are predicted at the risk characterization stage, the risk assessment process is repeated using additional data, refined assumptions and more complex equations and/or risk management measures are taken.
