The Health Impact Assessment (HIA) under REACH includes a comprehensive narrative description of all the expected changes or impacts: 1) The human health endpoints affected both qualitatively and quantitatively; 2)The possible values used associated with human health end-points and the estimates of monetised impacts; 3) The significance of the impacts; 4) The certainty and confidence in the description of the impacts; 5) All relevant assumptions/decisions and estimated uncertainties relating to what has been included, measurements or data sources.

Link to guidance.