LCA Engineering flashcards
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32 cards. Read the term and the definition here. The deck at the top of this page is optional.
- Functional unit
- A quantified description of the performance a product system must deliver, used as the reference to which all inventory and impact results are scaled. It must be measurable and function-based.
- Reference flow
- The amount of product, in mass, volume, or pieces, required to fulfil one functional unit. All process inputs and outputs are normalized to this flow.
- Attributional LCA
- An LCA that describes the share of global environmental burdens attributable to a product's life cycle, using average suppliers and existing supply chains. It answers what part of total burdens belongs to the product.
- Consequential LCA
- An LCA that estimates how environmental burdens change in response to a decision, using marginal suppliers and market-mediated effects. It answers what happens if demand for the product changes.
- Cradle-to-gate boundary
- A system boundary covering raw material extraction through production up to the factory gate, excluding distribution, use, and end-of-life. It is common for intermediate products.
- Elementary flow
- Material or energy that enters the system from the environment or leaves it to the environment without prior human transformation, such as crude oil in the ground or CO2 emitted to air.
- ISO 14040
- The international standard covering the principles and framework of LCA. It describes the four phases and general requirements but does not prescribe detailed methodological rules.
- ISO 14044
- The international standard specifying requirements and guidelines for LCA, including goal and scope, inventory, impact assessment, interpretation, reporting, and critical review. It complements ISO 14040.
- Critical review panel
- An independent review required by ISO 14044 when a comparative assertion is disclosed to the public. It verifies method, data, and conclusions, and typically includes interested parties.
- Allocation hierarchy
- ISO 14044 order for handling multi-functional processes: first avoid allocation by subdivision or system expansion, then use physical relationships, then other relationships such as economic value.
- System expansion
- A method to avoid allocation by adding the functions of co-products to the studied system and crediting the substituted products, so the system delivers an expanded function.
- Economic allocation
- Allocating shared process burdens among co-products in proportion to their economic value or revenue. It is used when physical relationships are not suitable, and must be justified.
- Cut-off criteria
- Quantified thresholds for mass, energy, or environmental significance that determine which inputs, outputs, or processes may be excluded from the inventory. Exclusions must be justified and checked.
- Classification
- The LCIA step that assigns each elementary flow from the inventory to one or more impact categories, for example assigning methane to global warming and to photochemical ozone formation.
- Characterization factor
- A factor that converts an inventory flow into a common impact category unit, such as the 100-year global warming potential of a greenhouse gas in kg CO2-equivalent per kg.
- Midpoint indicator
- An LCIA indicator located partway along the cause-effect chain, such as kg CO2-eq for climate change or kg SO2-eq for acidification. It is more certain but less interpretable than endpoint.
- Endpoint indicator
- An LCIA indicator at the end of the cause-effect chain, expressing damage to human health, ecosystem quality, or resources, for example disability-adjusted life years or species lost per year.
- Normalization
- An optional LCIA step that divides characterized results by a reference value, such as regional per-capita emissions, to express results relative to a common baseline.
- Weighting
- An optional LCIA step that aggregates different impact categories using value-based factors reflecting relative importance. It is subjective and must be transparent and justified.
- Sensitivity analysis
- A systematic procedure that varies key assumptions or parameters, such as allocation method or electricity mix, and reports how results and conclusions change in response.
- Uncertainty analysis
- A procedure that quantifies variability and uncertainty in input data and propagates it through the model, often by Monte Carlo simulation, to produce a range around results.
- Pedigree matrix
- A data quality scoring scheme rating datasets on reliability, completeness, temporal, geographic, and technological correlation. Scores are converted into uncertainty factors in databases such as ecoinvent.
- Foreground data
- Data collected specifically for the product system under study, such as site energy use and material quantities. They are distinguished from background data taken from databases.
- Background data
- Data describing upstream processes not directly controlled by the practitioner, such as electricity generation or material production, typically taken from LCA databases like ecoinvent.
- ecoinvent system models
- Alternative modelling approaches in the ecoinvent database, including cut-off, APOS, and consequential, which differ in how recycling and multi-functional processes are allocated.
- ISO 14067
- The standard specifying principles, requirements, and guidelines for quantifying and reporting the carbon footprint of a product, based on ISO 14040 and ISO 14044.
- Environmental Product Declaration
- A Type III environmental declaration under ISO 14025 providing quantified, independently verified life cycle environmental data for a product, based on product category rules.
- Product category rules
- Rules that define the functional or declared unit, system boundary, cut-off criteria, and impact indicators for EPDs within a specific product category, ensuring comparability.
- Type I environmental label
- A voluntary, third-party certified, multi-criteria label based on life cycle considerations, awarded to products meeting specified environmental criteria within a product category, per ISO 14024.
- Type II environmental claim
- A self-declared environmental claim made by a manufacturer without independent certification, governed by ISO 14021, which requires claims to be specific, verifiable, and not misleading.
- Circular footprint formula
- A method in the EU Product Environmental Footprint that credits recycled content and end-of-life recycling while applying a quality factor to secondary materials, reflecting circularity.
- Life Cycle Sustainability Assessment
- An assessment combining environmental LCA, life cycle costing, and social LCA on the same functional unit and system boundary to evaluate all three sustainability pillars.