Life Cycle Assessment: Laying the Foundation for a Transparent Supply Chain

Shopping Bag Case Study

September 26, 2013

Dr. Anahita Williamson

Director

Kate Winnebeck

LCACP, Senior EHS Specialist

New York State Pollution Prevention Institute at RIT

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

Reuse Remanufacture Recycle

Use End of Use Processing

Waste Treatment

LCA Methodology

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

– Step 4: Report results. product life-cycle. Evaluate opportunities to reduce energy, material inputs, or environmental impacts at each stage of the

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

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 Sustainability Victoria, Comparison of existing life cycle analysis of shopping bag alternatives, Apr07 .

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 1. As a group, draw the boundaries or process flow of the system

System Boundaries

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

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

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

Material Mass per bag Relative Capacity Bags per Year Mass bags per year

Single use plastic

HDPE 7g 1 520 3640g

Single use paper

Unbleached Kraft paper 42.6g

0.9

578 24622.8g

Reusable plastic

Polypropylene 95g 1.1

4.55

432.25g

Reusable cotton

Cotton 85g 1.1

4.55

386.75g

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

Step 2: Life Cycle Inventory

Inventory collected from multiple sources

Inputs

Materials Manufacturing Energy

Outputs

Products Distribution Raw Materials database Customer use Air, Water and Solid Emissions End of use processing

Toner Life-cycle Inventory

Ref: A.Ahmadi,et.al, J.Clean.Prod., 2003

Toner Life-cycle Inventory

Ref: A.Ahmadi,et.al, J.Clean.Prod., 2003

Impact Assessment Results

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

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

Life Cycle Inventory

Single Use Plastic Bag Polyethylene, HDPE, granulate Stretch blow moulding Transport, 100km manufacturing to customer Transport, municipal waste collection, 10km customer to landfill Disposal, polyethylene, 0.4% water, to sanitary landfill Single Use Paper Bag Kraft paper, unbleached, at plant Production of paper bags Transport, 100km manufacturing to customer Transport, municipal waste collection, 10km customer to landfill/recycling Disposal, packaging paper, to sanitary landfill Recycling paper Reusable Plastic Bag Polypropylene, granulate Extrusion, plastic film Transport, 100km manufacturing to customer Transport, municipal waste collection, 10km customer to landfill Disposal, polypropylene, to sanitary landfill Reusable Cotton Bag Textile, woven cotton, at plant Transport, 100km manufacturing to customer Transport, municipal waste collection, 10km customer to landfill Disposal, inert material, to sanitary landfill

3640g 3640g 0.364tkm

0.0364tkm

3640g 24622.8g

24622.8g

2.4623tkm

0.24623tkm

12311g 12311g 432.25g

432.25g

0.043225tkm

0.0043225tkm

432.25g

386.75g

0.03867tkm

0.0038675tkm

386.75g

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

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 Fate analysis Exposure & effect analysis Damage analysis

Damage Categories

Human Health Ecosystem Quality Mineral & Fossil Resources

Single Score Indicator

Normalization & weighting

Total Normalized Impact

Normalized Environmental Impact

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 1. Identify significant issues 2. Evaluate results for completeness, consistency, and sensitivity of the data 3. Draw conclusions & make recommendations consistent with the goal & scope of the study

Interpreting Results

• Which bag has the lowest environmental impact? Which bag has the highest? • Let’s consider cost of the bags.

Bag Type

Material Cost per bag Cost per year

Single use plastic

HDPE $0.02 $10.40

Single use paper

Unbleached Kraft paper $0.07 $40.46

Reusable plastic

Polypropylene $1 $4.55

Reusable cotton

Cotton $6 $27.30

• 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?

Anahita Williamson, PhD

Director Email: [email protected]

Phone: 585-475-4561

Kate Winnebeck, LCACP

Sr. Environmental Health & Safety Specialist Email: [email protected]

Phone: 585-475-5390 New York State Pollution Prevention Institute http://www.nysp2i.rit.edu