LCA EXAM Flashcards
State the concept of a life cycle. What is the life cycle concept in a product assessment?
The life cycle of a product **refers **to the complete set of stages a product goes through, from the extraction of raw materials to its final disposal or recycling. This concept helps in indentifying and evaluating the environmental impacts associated with each stage.
What are the stages of a product’s life cycle?
Raw material extraction, material manufacture, product manufacture, use stage, end of life
What are the different life cycle perspectives?
cradle to grave : from raw materials extraction -> end of life (all stages)
cradle to gate : from raw materials extraction -> gate (until the product leaves the factory)
cradle to cradle : advocates for closed-loops systems, where waste is recycle or reused instead of being discard.
What is a primary source of data?
Data collected by the entity conducting the analysis from original measurements or observations, making it a reliable source of information.
What is a secondary source of data?
Data collected and processed by others, often found in reports, databses or publications. These sources may introduce biases **so verifyng with **primary sources is recommended.
Define emission factor
It is a value representing the amount of emissions released per unit of activity or energy consumed in a process. It is used in environmental analysis and often sourced from government databases.
Describe three-step method for quantitative and qualitative assessment
- Description of the method: present a detailed explanation of the steps, tools, or approaches used to complete the task.
- present the results (quantitative or qualitative)
- **critically assess or validate **the results ensuring they are accurate and relevant to the study’s goals.
List the ISO Life Cycle Assessment Standards
ISO 14040: 2006 - Environmental management - LCA- PRINCIPLES AND FRAMEWORK
ISO 14044: 2006 - Environmental management -LCA - REQUIREMENTS AND GUIDELENESS
What are the ISO LCA Standard’s 4 phases?
1. Goals and scope definition: define purpose, system boundaries and functional unit of the study.
2. LC inventory: collect data of inputs and outputs of the system.
3. LC impact assessment: translate data from LC inventory to environmental impacts (eg climate change, resource depletion) **by categoryzing and assessing the potential effects. **
4. Interpretation: evaluate results, draw conclussions and provide recommendations.
What is LCI?
It is a phase of LCA that involves collecting and quantifying the inputs (e.g., raw material and energy) and outputs (e.g., emissions, waste) associated with a product or a system. It is the foundation for further analysis (LCIA).
What are the ISO requirements for goal statements in an LCA study?
The goal statements include: (1)intended application: how the results of the study will be used, (2) reasons for conducting the study , (3) audience, (4) comparative assertions: state if the results will be used for public comparative claims.
Describe product system
It is a set of interconnected processess that tranform inputs into outputs to perform a specific function.
Describe function and functional unit with examples.
-
Function – The purpose or performance characteristic of a *product system. *
Examples:
-A power plant generates electricity.
-A light bulb provides light. -
Functional Unit – It is a defined, measurable unit that quantifies the function allowing to compare different systems or products.
Examples:
-Power plant: “One kilowatt-hour of electricity produced”
-Hand dryer: “One pair of hands dried”
-Light bulb: “Providing 100 lumen-hours of light”.
What is a system boundary?
Defines which processes and flows of a product system are included in the study, based on the study’s goals. It determines the scope of the analysis by specifying what is considered inside or outside the assessment.
What are direct and indirect effects?
direct-> immediate environmental impacts caused by a process (e.g., emissions from fuel combustion in a car)
indirect-> secondary impacts result from related activities (e.g., emissions from generating the electricity used to charge an electric car).
What are elementary flows?
As defined by ISO 14044, elementary flows are material or energy that enter or leave the system directly from or to the environment, without further processing. (CO2 emissions, water intake)
What is a unit process?
The smallest element of a product system considered in the analysis, where input and output data are quantified. It represents a single step or activity withing the overal system.
What is the difference between LCI and LCIA?
LCI (Life Cycle Inventory) – Focuses on accounting and quantifying inputs and outputs (materials, energy, emissions) without assessing environmental impacts.
LCIA (Life Cycle Impact Assessment) – Analyzes the environmental impacts associated with the inputs and outputs identified in the LCI phase.
When can be comparative LCA studies made?
Comparative LCA studies can only be made if the products being compared use the same study design parameters:
-Goal and scope
-Functional unit
-System boundary
Additionally, the study must be an LCA (not just an LCI), and a sensitivity analysis must be conducted.
What is a life cycle inventory result?
The quantified data of all inputs (e.g.,materials, energy) and outputs (e.g., waste, emissions) across the entire life cycle within the system boundary. All the data collected in the LCI phase.
Describe process flow diagram approach
The process flow diagram approach combines the results from multiple unit processes into a single estimate of total impact (e.g., total CO₂ per kWh). It represents the product system’s processes in a diagram, showing how inputs and outputs flow between them.
Qué significa combinar los resultados de múltiples unit processes:
Unit processes: Son los pasos más pequeños dentro de un sistema (por ejemplo, generar electricidad, transportar materiales, o fabricar un componente).
El enfoque combina los impactos de cada paso (como las emisiones de CO₂ de cada proceso) en un único resultado global.
Ejemplo: Si el sistema incluye:
Una planta de energía (emite 0.5 kg de CO₂ por kWh).
Transporte de materiales (emite 0.3 kg de CO₂ por kWh).
Fabricación del producto (emite 0.2 kg de CO₂ por kWh).
Resultado combinado: 1.0 kg de CO₂/kWh para todo el sistema.
What is the task of life cycle impact assessment (LCIA)?
LCIA evaluates the potential environmental impacts of a product system by translating the LCI data into meaningful impact categories (climate changes, resource depletion, human health) to assess their significance
What is an impact category?
An impact category represents a specific environmental concern in LCA (e.g., global warming, climate change, water use) and includes the scale of impact (local or global) and the LCI data used to assess these impacts. The list of impact categories is not exhaustive and may vary based on the study’s focus.
List the frequently used impact categories of LCIA
a. Global Warming
b. Stratospheric Ozone Depletion
c. Acidification
d. Eutrophication
e. Photochemical Smog
f. Terrestrial Toxicity
g. Aquatic Toxicity
h. Human Health
i. Resource Depletion
j. Land Use
k. Water Use
