1. Life Cycle Assessment: Laying the Foundation for a Transparent Supply Chain Shopping Bag Case Study September 26, Dr. Anahita Williamson Director Kate Winnebeck LCACP, Senior EHS Specialist New York State Pollution Prevention Institute at RIT

2. Life Cycle Assessment
Life Cycle Assessment (LCA) is a technique used to quantify the environmental impact of a product from raw material acquisition through end of life disposition (cradle-to-grave)
Material Extraction
Processing
Component Fabrication
Product Assembly
Packaging & Distribution
Use
End of Use Processing
Reuse
Remanufacture
Helps identify the environmental impact of processes in product design decisions
Commonly used to quantify the environmental impacts of products to enable comparisons between different products performing the same function
Recycle
Waste Treatment

3. LCA Methodology
A Life Cycle Assessment is carried out in four distinct phases: (ISO 14040, 14044)
Step 1: Goal definition and scoping. Identify the LCA's purpose, the products of the study, and determine the boundaries. (what is and is not included in the study)
Step 2: Life-cycle inventory. Quantify the energy and raw material inputs and environmental releases associated with each life cycle phase.
Step 3: Impact analysis. Assess the impacts on human health and the environment.
Step 4: Report results. Evaluate opportunities to reduce energy, material inputs, or environmental impacts at each stage of the product life-cycle.

4. Step 1: Goal Definition and Scoping
Define the goal:
Intended application of the study
Intended audience
Define the scope:
Identify the product system to be studied
Define the functional unit
Define the boundaries of the product system
Identify assumptions and limitations of the study
Select impact categories to be included

5. Today’s Example
You own a grocery store and customers are starting to request that you sell reusable shopping bags. You are curious which type of bag has the lowest environmental impact. In order to quantify and compare the bag options, a streamlined LCA is performed.
Goal:
Determine which grocery bag – single use paper, single use plastic, reusable plastic, or reusable cotton – has the lowest environmental impact
Single use plastic – HDPE
Reusable –polypropylene – Wegman’s tote (woven bag)
Sustainability Victoria, Comparison of existing life cycle analysis of shopping bag alternatives, Apr07.

6. Draw the System Boundaries
Assumptions:
All bags are manufactured 100km from the customer
All bags travel 10km from the customer to the end of life
Half of paper bags are recycled at end of life, half go to landfill
Plastic & cotton bags go to landfill at end of life
As a group, draw the boundaries or process flow of the system

7. System Boundaries Material Extraction Processing Bag Manufacture
Packaging & Distribution
Use
End of Life
Single use & reusable plastic bag
Extracting petroleum
Transform petroleum into plastic
Form plastic into bags
Packaging & Distribution
Use
Landfill
Paper bag
Cutting down trees
Transform trees into paper
Form paper into bags
Packaging & Distribution
Use
50/50 to Landfill & Recycling

8. Functional Unit
The functional unit is a measure of the function of the studied system
Provides a reference to which the inputs and outputs can be related
Enables comparison of two essentially different systems
Examples
The functional unit for a paint system may be defined as the unit surface protected for 10 years
The functional unit for a printer may be defined as the number of printed pages of an acceptable print quality
The functional unit for power generation systems may be defined as 1kWh of electricity

9. Functional Unit
The amount of shopping bags consumed by a household to carry 70 grocery items home from the supermarket each week for 52 weeks
Bag Type
Single use plastic
Single use paper
Reusable plastic
Reusable cotton
Material
HDPE
Unbleached Kraft paper
Polypropylene
Cotton
Mass per bag 7g
42.6g
95g
85g
Relative Capacity 1
0.9
1.1
Bags per Year
520
578
4.55
Mass bags per year
3640g g
432.25g
386.75g

10. Step 2: Life Cycle Inventory
Highly data intensive
Detailed mass & energy balances performed over life-cycle
Advantages: measure data & define baseline metrics of life-cycle processes
Challenges: Assumptions made when data unavailable

11. Step 2: Life Cycle Inventory
End of use processing
Customer use
Distribution
Manufacturing
Materials
Inventory collected from multiple sources
Inputs
Energy
Raw
Materials
Outputs
Products
Air, Water and
Solid Emissions
database

12. Toner Life-cycle Inventory
Looking at final system
Ref: A.Ahmadi,et.al, J.Clean.Prod., 2003

13. Toner Life-cycle Inventory
Toner Manuf. really does not have major impact on overall life-cycle of the toner
Shows how the different sections of the system compare to one another
The post-production processes dominate the categories
Link between air emissions and energy use, which results from the much larger quantities of energy related air emissions in relation to manufacturing process air emissions
Customer use is the most energy intensive process of the system  energy required to transfer the metric ton of toner onto the paper
End of use Processing also has a significant impact  mainly from the removal of the toner from the paper that is recycled (de-inking process); De-inking also accounts for large amount of wastewater and solid waste (toner that is removed from paper; note: waste paper not included in analysis)
Toner manuf. Process impacts small compared to post-consumer processes
Ref: A.Ahmadi,et.al, J.Clean.Prod., 2003

14. Impact Assessment Results
Impact assessment converts the inventory into impact categories or end points which details the human health and environmental effects.

15. High Density Polyethylene Inventory
Peer reviewed datasets imbedded in software
Data has been collected by others and represents actual operations
Include:
Known inputs
Emissions to air
Emissions to water
Emissions to soil
Wastes and emissions sent to treatment
Ability to modify datasets based on your own data
2. As a group, choose one of the four bags and list the processes that are included in the inventory

16. Life Cycle Inventory Single Use Plastic Bag
Polyethylene, HDPE, granulate
3640g
Stretch blow moulding
Transport, 100km manufacturing to customer
0.364tkm
Transport, municipal waste collection, 10km customer to landfill
0.0364tkm
Disposal, polyethylene, 0.4% water, to sanitary landfill
Single Use Paper Bag
Kraft paper, unbleached, at plant g
Production of paper bags
2.4623tkm
Transport, municipal waste collection, 10km customer to landfill/recycling
tkm
Disposal, packaging paper, to sanitary landfill
12311g
Recycling paper
Reusable Plastic Bag
Polypropylene, granulate
432.25g
Extrusion, plastic film
Transport, 100km manufacturing to customer
tkm
Transport, municipal waste collection, 10km customer to landfill
tkm
Disposal, polypropylene, to sanitary landfill
Reusable Cotton Bag
Textile, woven cotton, at plant
386.75g
tkm
tkm
Disposal, inert material, to sanitary landfill

17. Step 3: Impact Assessment
Converts the inventory into impact categories or mid/end points which explain the environmental effect
Impact categories may include: carcinogens, respiratory organics and inorganics, climate change, radiation, ozone layer, ecotoxicity, acidification/eutrophication, land use, minerals, fossil fuels
Can apply weights to impact categories

18. Single Score Indicator
Impact Assessment
Life Cycle Inventory
NOx
SOx
Pesticides
Heavy metals
CO2
VOCs
Particulates
Chemicals
Impact Categories
Concentration in air, water, food
Concentration greenhouse gases
Changed pH and nutrient availability
Change in habitat
Fossil fuel availability
Category Indicators
Local effects on species
Climate change
Ozone layer depletion
Radiation
Respiratory effects
Cancer cases and types
Surplus energy
Damage Categories
Single Score Indicator
Human Health
Ecosystem Quality
Mineral & Fossil Resources
FATE ANALYSIS – when a chemical is released, it may end up in the air, water, or soil
This step looks at the properties of the substance to determine where it will end up – ie. water soluble substance will have a higher concentration in water
Also considers degradability of the substance
Models transfer of the chemical between environmental compartments and degradation of the chemical – result is the concentration of the substance in air, water, soil, & food
EXPOSURE ANALYSIS – determine how much of a substance is taken in by people & the environment
EFFECT ANALYSIS – predict the types and frequencies of effects based on the amount taken in by people & the environment in the exposure analysis
DAMAGE ANALYSIS – predicted diseases/effects are translated to one unit
Ie. EcoIndicator 99:
Human Health = DALY = disability adjusted life year
Ecosystem Quality = loss of species over a certain area
Resources = surplus energy needed for future extraction of minerals and fossil fuels
Normalization & Weighting – determine the importance of effects and weigh them appropriately
Can use weighting factors built into impact assessment models or can modify models to apply your own weighting
Ie. EcoIndicator 99 – human health & ecosystem are equivalent, resources is ½ as important, determined by panel of scientific experts
Fate analysis
Exposure & effect analysis
Damage analysis
Normalization & weighting

19. Total Normalized Impact

20. Normalized Environmental Impact

21. Step 4: Report Results
Life cycle interpretation: findings of the inventory analysis or impact assessment are evaluated in relation to the goal and scope of the study to reach conclusions and recommendations
Identify significant issues
Evaluate results for completeness, consistency, and sensitivity of the data
Draw conclusions & make recommendations consistent with the goal & scope of the study

22. Interpreting Results
Which bag has the lowest environmental impact? Which bag has the highest?
Let’s consider cost of the bags.
As the store owner, does the cost information change which type of bag you would promote? How? 
As a shopper, does the cost information change which type of bag you would use? How?
Bag Type
Single use plastic
Single use paper
Reusable plastic
Reusable cotton
Material
HDPE
Unbleached Kraft paper
Polypropylene
Cotton
Cost per bag
$0.02
$0.07 $1 $6
Cost per year
$10.40
$40.46
$4.55
$27.30

23. Anahita Williamson, PhD
Director
Phone:
Kate Winnebeck, LCACP Sr. Environmental Health & Safety Specialist
Phone:
New York State Pollution Prevention Institute