Appendix C - Hazardous Facility Screening Procedure FF, FH, and FF are adjustment Factors for the Fire/Explosion, Health, and Ecological Effect Groups, respectively. Adjusted Threshold The Adjusted Threshold (T) is calculated for each Effect Group by multiplying the Base Threshold by the relevant Adjustment Factor. For example: B x FF = T Adjusted Threshold for a substance in the Fire/Explosion Effect Group B x FH = T Adjusted Threshold for a substance in the Health Effect Group B x FE = T Adjusted Threshold for a substance in the Ecological Effect Group The Adjusted Threshold defines the amount of a substance generating no significant off-site effects when released, after taking account of site and substance consideration. Effects Ratio The Effects Ratio (R) represents the proposed quantity of hazardous substance divided by the Adjusted Threshold. Effects Ratios fulfil two important purposes. First, they define the hazardous facility threshold and determine the activities status within the Plan. The status is set by the highest value for R in any of the Effect Groups. Second, they assess the cumulative effects that may be created by several hazardous substances on the same site. By using a ratio it is possible to aggregate the assessment of effects from multiple substances on the same site. App C - 3