Characterisation Method Name: 
HF impact on NEX 
Version: 
1999 
Date Completed: 
1999 
Principal Method Name: 
EPS: acidification pathway and aerosol transformation pathway 
Method Description: 
NEX is Normalised EXtinction of species. Model 1, acidification pathway The characterisation factor is determined by an equivalency method using SO2 as a reference. Equivalency factor Due to its lower molecular weight 1 kg of hydrogen fluoride will give (64/2)/20 = 1.6 times as much protons as one kg of sulphur dioxide. Calculation of pathway specific characterisation factor The acidification pathway specific characterisation factor of SO2 for NEX is 1.18E14 per kg SO2. The characterisation factor of HF for NEX will thus be 1.6 * 1.18E14 = 1.89E14 per kg HF. Model 2, aerosol transformation pathway The characterisation factor is determined by an equivalency method using PM10 as a reference. Equivalency factor The same equivalency factor is used as in "HF impact on severe morbidity", i.e. 1.8 kg ‘effective’ PM10/kg HF. Calculation of pathway specific characterisation factor The characterisation factor of PM10 for NEX is 1.08E13 per kg PM10. The characterisation factor of HF for NEX will thus be 1.80*(1.08E13 ) = 1.94E13 per kg HF. Calculation of characterisation factor The added characterisation factor of HF for NEX considering both pathways is thus 1.92E10 + 1.08E13 = 1.92E10 per kg HF. 
Literature Reference: 
Steen B (1999b): A systematic approach to environmental priority strategies in product development (EPS). Version 2000 – Models and data of the default method CPM report Chalmers University of Technology Sweden 
Methodological Range: 
The system is global and the time period is 1990. The spatial system borders are wide enough to contain all of the modelled impact quantity (NEX on a global or local level). The response time for the modelled quantity is normally in the order of several years to decades, depending on the reproduction cycles of the NEX and on the volumes and alkalinity of the inland waters at risk for acidification. This means that present observed impacts are mainly caused by emissions several years ago. Despite this the characterisation factor of HF for NEX will be modelled as if everything happened within 1990. The magnitude of the error, which may be introduced through this, is discussed and estimated later. 
Notes: 
Characterisation Parameter  Category Indicator  Impact Indication Principle  Aspect  Substance  Quantity  Unit  Notes  
CFactor  NEX  EPS/2000 

HF  1.92E10  NEX/kg  2 pathways 