How to estimate the eco-costs of a product with an EPD
The IdematLightLCA app provides the opportunity to make quick
estimates of the eco-costs of a product with an EPD. The procedure is quite
straight foreward: select all midpoint lines (climate change, acidification,
eutofication, photochemical oxidants) as well as the NRPM and the RPEM from
the 'EPD midpoints' category, and add in the LCA input screen (under processes)
all quantities A1+A2+A3 of the EPD.
For a cradle-to-gate calculation of metal products, the amount of metals (kg) must be added as well (applying the 'depletion.....' lines in the 'EPD midpoints' category), to calculate the eco-costs of resource depletion.
The EPD quantities of A4 trough C4, if available, might be added as well (under use phase), although these numbers seem less relevant because of case specific variations.
To account for the negative numbers (credits) in block D, if available, select all 'EoL....' lines from the 'EPD midpoint' category, and add the credits from de EPD as positive numbers in the LCA input screen (under use phase). Note that the sum of the emissions in A1+A2+A3 (leaving out the metal depletion data) plus the emission credits of D give a good indication for C2C calculations for the circular economy.
To understand the calculation, background information is given in the text below.
Note: For general information on the IdematLightLCA data, limitations, and accuracy, ckick here.
The text below is a copy of Appendix VI of the book "A practical Guide to LCA for students, designres, and business managers".
Converting EPD data in eco-costs (cradle-to-gate)
Important sources of eco-costs of products in the building industry
are EPDs (Environmental Product Declarations). Germany and France have databases
with hundreds of products (http://construction-environment.com, www.inies.fr).
Although the full LCIs are often not available, the major information which
is required to make an estimate of eco-costs is given in the text of the documents.
The fact that the Calculation Rules for the building industry have recently
been standardised in EN 15804, makes that EPDs can be used now for environmental
EPDs use sub-system numbers which are depicted in the adjacent figure.
By far the most EPDs are cradle-to-gate. For these EPDs only the first 3 blocks are included:
A1 all upstream processes (also called background processes)
A2 transport to the production site
A3 all processes at the production site plus outsourced activities (also called foreground processes)
Since most of the manufacturers hate to give detailed information on their core processes, by far the most EPDs provide only information on the sum of A1+A2+A3.
There are two ways to calculate the eco-costs of EPDs: a method
A and a method B. Method A is the most accurate one, based on available data
in the text about the materials in the product. Method A is basically the
'normal' Fast Track method, with a slight complication to calculate the energy
requirements in block A3 (if significant). There are, however, many EPDs where
detailed data on the materials in the product is missing. Then method B is
required, based on the midpoints which are given in each EPD. Do not mix method
A and B, to avoid double counting.
Eco-costs calculation method A
The easiest and best way to calculate the cradle-to-gate eco-costs of such a product is to start with the 'bill of materials' (the materials composition) of a product, add the estimated production waste for each material (especially important for wooden products like window frames), and multiply it with the ecocosts/kg of the Idemat and Idematapp data tables. A simple summation results then in the total eco-costs of block A1 , which is by far the most important contribution to the total eco-costs cradle-to-gate of most products.
Add for block A2 the inland transport scenario (keep in mind that the Idemat data are calculated for products from the Rotterdam harbour, but that might be replaced by any other big European harbour).
The emission of toxic substances of block A3 is negligible for most production sites in Western Europe . The only unknown eco-costs are the eco-costs of heat and electricity.
When the EPDs give details on the energy use in block A3 (the so called NRPE or PENRE = Primary Energy Non-Renewable, plus the RPEE or PERE = Primary Energy REnewable), the eco-costs of it can be calculated by multiplying the NRPE+RPEE or PENRE+PERE with the eco-costs of Idemat 2020 Industrial Heat General (0.0109 euro/MJ).
Unfortunately most EPDs give only data for block A1+A2+A3 in total. Then there is a simple way to estimate the eco-costs of heat and electricity of block A3 in three steps:
Step 1. Calculate the carbon footprint (kg CO2e) of your imput so far, and subtract that from the carbon footprint of A1+A2+A3 of the EPD. The result is the carbon footprint of block A3.
Step 2. Devide the carbon footprinf (kg CO2e) by 0.051 to get the equivalent amount of MJ 'heat, industrial' (or, devide by 5.1 to get the amount in 100 MJ)..
Step 3. Add the MJ heat industrial to your calculation. The result is that the total eco-costs of heat and energy of block A3 is added to your LCA.
Eco-costs calculation method B
For products which are made from renewable or non-scarce materials only (e.g. wood from plantations, sand, stone), the 'eco-costs of metals depletion' is negligible. The total eco-costs can then be calculated on the basis of the impact categories ('midpoints') as given in the EPD, and the conversion factors of Table A1.
|Impact Category in EN 15804||Quantity and Unit||Eco-costs|
|Acidification for soil and water||1 kg SO2 equiv||8.25 €|
|Ozone Depletion||1 kg CFC 11 equiv||0.000 €|
|Global Warming||1 kg CO2 equiv||0.135 €|
|Eutrophication||1 kg (PO4)3- equiv||3.90 €|
|Photochemical ozone creation||1 kg Ethene equiv||9.70 €|
Table A1. The relationship between impact categories in EN 15804 and eco-costs
This calculation method can also be used when the quantities
of metals, rare earth, and fossil based polymers are relatively low. The 'eco-costs
of resource depletion' (containing depletion of elements + water + land-use)
form Table A2 must be added then to the calculation on the basis of the impact
categories of Table A1.
Note. Unfortunately, the 'eco-costs of resource depletion' can not derived from the 'ADP for non fossil resources' .
Table A2 shows a list of the most common materials (see the
Idemat or Idematapp table for other materials, such as precious metals, rare
earth, paints, textiles, specific wood species, and special plastics). Note
that the eco-costs of resource depletion in the Idemat tables are from-cradle-to-gate,
including the required production facilities.
|materials in EN 15804||Eco-costs of resource depletion (euro/kg)||materials in EN 15804||Eco-costs of resource depletion (euro/kg)|
|Aluminium trade mix||
|BR and PIB (butadiene rubber and butyl rubber)||
|Copper wire, plate, pipe, trade mix||
|EPDM (ethylene propylene diene monomer rubber)||
|Lead trade mix||
|EVA (ethylene vinyl acetate rubber)||
|Magnesium trade mix||
|SBR (Styrene butadiene rubber)||
|Nickel trade mix||
|ABS (Acrylonitrile butadiene styrene)||
|Zinc trade mix||
|PA 66 (Nylon 66, Polyamide 6-6)||
|Steel beams, pipes, sheet, market mix||
|Inox X5CrNi18 (304)||
|Inox X5CrNiMo18 (316)||
|PET (bottle grade)||
|Recycled Inox (market average)||
|PMMA (Polymethyl methacrylate)||
|POM (Polyoxymethyleen, polyacetaal)||
|Red clay brick, sand-lime brick, tiles||
|Sand and gravel||
|PTFE (Teflon, Polytetrafluoroethylene)||
|Glass, uncoated for windows etc.||
Table A2. The eco-costs of resource depletion to be applied to EN 15804 calculations (Idematapp2016 data)
Sometimes the type of plastic is not specified (this is often the case for EPDs of paint). Then the NRPM data in the EPD can be used (NRPM = Non Renewable. Primary Energy in Materials; also called PENRM). This indicator is in MJ, net calorific value. The conversion factor to 'Eco-costs of resource depletion' (euro/kg) is 0.0188 (euro/MJ), since the eco-osts of fossil fuel depletion is 0.8 euro per kg and the LHV of oil is 42.6 MJ/kg.
Three general remarks:
|1.||The EPDs of wood (and other bio-based materials) are often a bit confusing, since they are not made according to the current consensus in LCA|
| on how to deal with carbon sequestration
(storage from carbon in wood). In the EPDs the stored carbon 'in the product'
is often subtracted from the LCA result (approximately 1.85 kg CO2 per
kg dry wood), which leads to an overall negative carbon footprint score.
However, this is not general practice in LCA (i.e. biogenic CO2 is not
counted, since it ends up in the admosphere again at the end-of-life).
Often this amount of carbon sequestration is not specified separately,
so you must make your own calculation on your own correction (adding the
1.85 kg CO2 equivalent).
To calculate the end-of-life credit, take the RPEM ( Renewable Primary Energy in Materials; also called PERM), being the avoided use of fossil fuels (MJ). Take Idematapp 2020 Industrial Heat General = 0.0109 (euro/MJ) for combustion in electrical power plants (as it is done in the IdematLightLCA app for the circular economy case), or 55% of it for municipal waste incinerators (in IdematLightLCA. for waste treatment)
|2.||Note that the eco-costs of an EPD is in most of the time lower than the eco-cost of Idemat and Ecoinvent LCIs. There are three main reasons for that:|
|a.||EPDs are calculated excluding the infrastructure which is needed (e.g. the facilities for production). It may cause up to 15% difference|
|between Method A and B.|
|b.||Manufacturers who make EPDs perform in most of the cases better than the average manufacturing practice (the reason a manufacturer invests in time|
|and money to make an EPD is often that the manufacturer believes that the product is better than the average product in the market). Idemat and Ecoinvent data are averages of older processing techniques, instead of the Best Practice.|
|c.||Manufacturers who make EPDs try to keep the eco-score as low as possible, e.g. by taking short transport distances in their scenarios.|
|3.||Calculation method A gives a more accurate (slightly higher) result, since the eco-costs contain more, rather important, impact categories than specified|
|in EN 15804, like fine dust, ecotoxicity, and human toxicity|
Note. In many EPDs for metal products, the recycling credit (block D) is also given. As such these data cannot be used in isolation, since the amount of virgin material is not specified. However the sum of A1+A2+A3 + D (excluding resource depletion) gives a good estimate of eco-costs for a 100% C2C solution in the circular economy.