Indicators & their characterization factors

Impact Assessment Categories & their Characterization Factors

This is a list of characterization models and factors to use for the default environmental impact categories. This page is updated on a regular basis based on the latest developments in LCA methodology and ensuring the market stability of EPDs. The latest update to the recommendations was made 2018-05-30 (POFP) and 2018-06-08 (Water Scarcity Footprint).

Global warming potential (kg CO2 eq.)

GWP100, CML 2001 baseline. Version: January 2016.

Please notice that four GWP indicators shall be declared, which differentiates greenhouse gases depending on their origin: GWP-fossil, GWP-biogenic, GWP-land use and land use change (luluc), and GWP-TOTAL (the sum of the other three GWP indicators). More information can be found in the General Programme Instructions.

Original reference
IPCC (2013)

1 kg carbon dioxide = 1 kg CO2 eq.
1 kg methane = 28* kg CO2 eq.
1 kg dinitrogen oxide = 265 kg CO2 eq.

*Please note that the original source, IPCC (2013), differentiates "Fossil methane" from methane.

Acidification potential (kg SO2 eq.)

AP, CML 2001 non-baseline (fate not included), Version: January 2016.

Please notice the use of non-baseline characterization factors for acidification potential.

Original reference
Hauschild & Wenzel (1998)

1 kg ammonia = 1.88 kg SO2 eq.
1 kg nitrogen dioxide = 0.7 kg SO2 eq.
1 kg sulphur dioxide = 1 kg SO2 eq.

Eutrophication potential (kg PO43- eq.)

EP, CML 2001 baseline (fate not included), Version: January 2016.

Original reference
Heijungs et al. (1992)

1 kg phosphate = 1 kg PO43- eq.
1 kg ammonia = 0.35 kg kg PO43- eq.
1 kg COD (to freshwater) = 0.022 kg kg PO43- eq.

Photochemical oxidant formation potential (kg NMVOC eq.)

POFP, LOTOS-EUROS as applied in ReCiPe 2008

Original reference
Van Zelm et al 2008, ReCiPe 2008

1 kg carbon monoxide = 0.046 kg NMVOC eq.
1 kg nitrogen oxides = 1 kg NMVOC eq.

Abiotic depletion potential – Elements (kg Sb eq.)

ADPelements, CML 2001, baseline

Original reference
Oers, et al (2002)

1 kg antimony = 1 kg Sb eq.
1 kg aluminium = 1.09 * 10^-9 Sb eq.

Abiotic depletion potential – Fossil fuels (MJ, net calorific value)

ADPfossil fuels, CML 2001, baseline

Original reference
Oers, et al (2002)

1 kg coal hard = 27.91 MJ
1 kg coal soft, lignite = 13.96 MJ

Water Scarcity Footprint (WSF) (m3 H2O eq)

AWARE Method: WULCA Recommendations on characterization model for WSF 2015, 2017. CF at country level can be download (Excel files) from:

Cut-off rules can have important implications on the results. WULCA applies as cut-off rule: the maximum value for CF is set to 100 when Demand ≥ Availability (AWARE100). But, it has been proposed also two other cut-off rules for the AWARE Methods:

  • Maximum CF of 10 (AWARE10)
  • Maximum CF of 1000 (AWARE1000)

Original reference
Boulay et al (2017)

AWARE method is based on 1/AMD(1), the inverse of the difference between water availability per area and demand per area(2). It quantifies the potential of water deprivation, to either humans or ecosystems, and serves in calculating the impact score of water consumption at midpoint in LCA or to calculate a water scarcity footprint as per ISO 14046. It is based on the available water remaining (AWARE) per unit of surface in a given watershed relative to the world average, after human and aquatic ecosystem demands have been met.

(1) 1/AMD: the inverse of Availability - Demand
(2) What is the potential to deprive another user (human or ecosystem) when consuming water in this area?

The resulting characterization factor (CF) ranges between 0.1 and 100, and can be used to calculate WSF as defined in the ISO standard 14046:2015. The local AWARE factor is meant to be multiplied with the local water consumption inventory.

582 m3 H2O consumed per ton of grapes produced in Mendoza, Argentina:
WSF = 582 m3H2O x 54.15 (CFAgriAWARE100) = 31,518 m3eq/ton grape

Further information

For construction product EPDs compliant with EN 15804, Table 3 in EN 15804 (“Parameters describing environmental impacts”) shall be applied in the PCR instead of the indicators listed above. Characterization factors are available in Annex C of the standard.

To find corresponding methods available in your LCA software, such as SimaPro, GaBi or openLCA, please see the documentation or contact your LCA software provider. To see the compliance of different versions of the CML-IA, see the version history available on their website.

The source and version of the characterization models and the factors used shall be reported in the EPD. Alternative regional life cycle impact assessment methods and characterization factors are allowed to be calculated and displayed in addition to the default list. If so, the EPD shall contain an explanation of the difference between the different sets of indicators, as they may appear to the reader to display duplicate information.

Additional indicators

To better characterize the environmental performance of a product category, a PCR may list further mandatory or voluntary indicators of potential impacts. Also indicators not listed in the PCR may be declared if environmentally relevant for the product. Examples of further environmental impact categories to declare are:

  • emission of ozone-depleting gases, and
  • land use and land use change.

Examples of reports that provide recommendations on impact categories and indicators are UNEP/SETAC Global Guidance for Life Cycle Impact Assessment Indicators and the ILCD Recommendations for Life cycle impact assessment in the European context.