Eco-indicator 99

Eco-indicator 99 is the successor of Eco-indicator 95. Both methods use the damage-oriented approach. The development of the Eco-indicator 99 methodology started with the design of the weighting procedure. Traditionally in LCA the emissions and resource extractions are expressed as 10 or more different impact categories, like acidification, ozone layer depletion, ecotoxicity and resource extraction. For a panel of experts or non-experts it is very difficult to give meaningful weighting factors for such a large number and rather abstract impact categories. It was concluded that the panel should not be asked to weight the impact categories but the different types of damage that are caused by these impact categories. The other improvement was to limit the number of items that are to be assessed. As a result the panel, consisting of 365 persons from a Swiss LCA interest group, was asked to assess the seriousness of three damage categories:

  • Damage to Human Health, expressed as the number of year life lost and the number of years lived disabled. These are combined as Disability Adjusted Life Years (DALYs), an index that is also used by the Worldbank and WHO.
  • Damage to Ecosystem Quality, express as the loss of species over an certain area, during a certain time
  • Damage to Resources, expressed as the surplus energy needed for future extractions of minerals and fossil fuels.

In order to be able to use the weights for the three damage categories a series of complex damage
models had to be developed. In the figure below these models are represented in a schematic way.



eco 99

In general, the factors used in SimaPro do not deviate from the ones in the (updated) report. In case the report contained synonyms of substance names already available in the substance list of the SimaPro database, the existing names in the database are used. A distinction is made for emissions to agricultural soil and industrial soil, indicated with respectively (agr.) or (ind.) behind substance names emitted to soil.



Characterisation is factors are calculated at end-point level (damage). The damage model for emissions
includes fate analysis, exposure, effects analysis and damage analysis. This model is applied for the following impact categories:

  • Carcinogens

Carcinogenic affects due to emissions of carcinogenic substances to air, water and soil. Damage is expressed in Disability adjusted Life Years (DALY) / kg emission.

  • Respiratory organics

Respiratory effects resulting from summer smog, due to emissions of organic substances to air, causing respiratory effects. Damage is expressed in Disability adjusted Life Years (DALY) / kg emission.

  • Respiratory inorganics

Respiratory effects resulting from winter smog caused by emissions of dust, sulphur and nitrogen
oxides to air. Damage is expressed in Disability adjusted Life Years (DALY) / kg emission.

  • Climate change

Damage, expressed in DALY/kg emission, resulting from an increase of diseases and death caused
by climate change.

  • Radiation

Damage, expressed in DALY/kg emission, resulting from radioactive radiation

  • Ozone layer

Damage, expressed in DALY/kg emission, due to increased UV radiation as a result of emission of
ozone depleting substances to air.

  • Ecotoxicity

Damage to ecosystem quality, as a result of emission of ecotoxic substances to air, water and soil.
Damage is expressed in Potentially Affected Fraction (PAF)*m2*year/kg emission.

Acidification/ Eutrophication

Damage to ecosystem quality, as a result of emission of acidifying substances to air. Damage is expressed in Potentially Disappeared Fraction (PDF)*m2*year/kg emission.

Land use

Land use (in manmade systems) has impact on species diversity. Based on field observations, a scale is developed expressing species diversity per type of land use. Species diversity depends on the type of land use and the size of the area. Both regional effects and local effects are taken into account in the impact category:

  • Land use

Damage as a result of either conversion of land or occupation of land. Damage is expressed in
Potentially Disappeared Fraction (PDF)*m2*year/m2 or m2a.

Resource depletion

Mankind will always extract the best resources first, leaving the lower quality resources for future
extraction. The damage of resources will be experienced by future generations, as they will have to use
more effort to extract remaining resources. This extra effort is expressed as “surplus energy”.

  • Minerals

Surplus energy per kg mineral or ore, as a result of decreasing ore grades.


  • Fossil fuels

Surplus energy per extracted MJ, kg or m3 fossil fuel, as a result of lower quality resources.


Of course it is very important to pay attention to the uncertainties in the methodology that is used to
calculate the indicators. Two types are distinguished:

  • Uncertainties about the correctness of the models used
  • Data uncertainties

Data uncertainties are specified for most damage factors as squared geometric standard deviation in
the original reports, but not in the method in SimaPro. It is not useful to express the uncertainties of
the model as a distribution. Uncertainties about the model are related to subjective choices in the
model. In order to deal with them we developed three different versions of the methodology, using the
archetypes specified in Cultural Theory. The three versions of Eco-indicator 99 are:

  • The egalitarian perspective
  • The hierarchist perspective
  • The individualist perspective



Normalisation is performed on damage category level. Normalisation data is calculated on European level, mostly based on 1993 as base years, with some updates for the most important emissions.


 Download the Methods Manual (PDF, 0.6 MB) for a concise overview of the methods in SimaPro.