General Calculation rules
IDEMAT is in compliance with ISO 14040, 14044, EN15804, and the ILCD Handbook (“General guide for Life Cycle Assessment – Detailed guidance”), and has the following Calculation Rules:
- ‘cut-off” at the end-of-life (according to EN15804, and similar to Ecoinvent ‘allocation cut-off by classification’), where there is no carry over from the old product system to the new product system; ‘system expansion” is only applied when materials are combusted in reality, applying combustion efficiencies as they are in the real combustion systems.
- for the system boundary a 2% cut-off criterion is applied
- application of (carefully selected) case studies, or averages of groups of production systems, rather than statistical data
- the LCIs have the ‘unit’ approach, only the ‘remaining background processes’ have the ‘system’ approach (the disadvantage of the system approach is that LCIs become rapidly outdated, because of the fast changing electricity mix)
- electricity data are based on measured emissions (for Europe the E-PRTR data, for the USA the eGRID data), being fundamentally different from most other LCI databases, for further explanation of this issue see https://www.ecocostsvalue.com/lca/electricity-in-lca/
Electricity data on 373 countries and regions are available at https://www.ecocostsvalue.com/data/
- end-of-life credits for combustion with heat recovery (according to ISO 14044 section 4.3.3.1) as well as end-of-life credits for upcycling of metals and plastics (section D in EN15804) are provided in an extra set of generic LCIs, to facilitate LCA practitioners with practical data that are readily available for C2C calculations (in most cases, it is quite laborious to find or calculate the data on combustion energy and recycling).
- economic allocation is applied (exception: mass based allocation for chemical processes). Note that allocation on the basis of mass normally shifts eco-burden to byproducts (like waste with a small value/mass ratio). Allocation of recycled or biobased inputs to only a few co-products on the basis of the so called Mass Balance Approach is not allowed.
- for plastics and transport fuels, the ‘embodied fossil fuels’ are provided in the LCIs (‘oil & gas in materials’ and ‘oil & gas in transport fuels’) to cope with EN15804 requirements, and to cope with double counting issues in ISO 14044, section 4.4.2.2.3, in the eco-costs system (i.e. avoiding the double counting of fossil fuels in ‘fossil resource use’ and CO2 in ‘climate change’)
- the embodied fossil fuels are added to the LCIs for plastics, paints, and inks, at the gate of the production step, in line with the philosophy that it is an indicator for the plastic soup
- the IDEMAT datasets in Simapro and in OpenLCA have been developed for calculations in the eco-costs single indicator system, as well as CML, ReCiPe, CED, TRACI and EF 3. Take care with other indicator systems, since names of substances might be different.
Note. ReCiPe applies slightly different midpoint tables for human toxicity (cancer and non-cancer) and ecotoxicity.
- to enable correct eco-costs calculations with Ecoinvent ‘unit’ datasets, extra LCI data lines (see excel file ‘Ecoinvent Eco-costs corrections’) have been added; this is necessary to cope with the double counting issue of fossil fuels and CO2 emissions, as mentioned in the previous issue 10.
- in OpenLCA: the dataset in OpenLCA does avoid direct allocation; unit processes have been divided in sub-processes, applying ratios either based on mass (for mining), or based on economic values, prices (for end-products).
- in OpenLCA: when the reference flow in the reviewed paper is not 1 kg (m2, m3, MJ, etcetera), the quantity of the reference flow is given in the name of the process (since the output of the calculation is given for this reference flow), however, the output flow of this process to another process is always provided in a quantity of 1.
Note that this is different in Simapro, where the calculation output is always normalised to 1 (SI unit); where that is not practical, the output is giver ‘per piece’, where the content of the piece is given in the name of the process (example: the output of an IC is given in cm2).
- The idemat database is a database providing data on generic products, and it is intended to remain so. It is not intended to distinguish between products of different brands. However, the SIM Foundation encourages companies to produce their own data, using the Idemat dataset for the detailed calculations, and compare it with the generic product data of Idemat.
Note 1. The consequence of 1) and 6) is, that the further application starting from the sorted waste materials are free of the eco-burden of the previous product life. The new product life that starts with recycling of that waste, starts with zero eco-burden. (in OpenLCA this is effectuated with a zero mass flow, rather than creation a long list of dummy materials for ‘urban mining’).
See for further explanation FAQ 2.6
The recycling credit equals the eco-burden of the ‘secondary material’ minus eco-burden of the ‘primary material’, both cradle-to-gate, where the cradle of the secondary material is the stockpile of waste. Only the part of virgin material at the system input is counted (when 100% of the material at the input is secondary, there is no recycling credit, to avoid double-counting).
Note 2. The Idemat system adheres to the basic principle of the IPCC that the so called ‘short cycle’ CO2, i.e. biogenic CO2, is not counted in LCA, unless the product last longer than 100 years, See also LCA of wood. The detailed calculation rules for biobased plastic are given at (Biotechnology Industry org, 2010).
See for further information FAQ 2.3
The fact that biogenic CO2 emissions are not counted, as opposed to fossil based CO2 emissions, has much impact on calculations of combustion at end-of-life: biobased waste materials have a rather big end-of-life credit for combustion with heat recovery, in contrast with fossil based waste materials.
Note 3. With regard to point 6): for the end-of-life credits for combustion with heat recovery (according to ISO 14044 section 4.3.3.1) Idemat takes into account the fact that municipal waste incineration has only 55% efficiency of the efficiency of co-burning in electrical power plants (45% of the heat is lost, and therefore not part of the heat recovery). The result is that combustion of fossil based plastics (e.g. from packaging) in a municipal heat incinerator has a severe impact (eco-costs debit). The shift towards bioplastics, like PLA helps to mitigate this CO2 emission problem.
