SEPA
United States
Environmental Protection
Agency
EPA 744-S-08-001
June 2008
Wire and Cable Insulation and
Jacketing: Life-Cycle Assessments
for Selected Applications
Summary
-------
United States
Environmental Protection
Agency
EPA 744-S-08-001
June 2008
Wire and Cable Insulation and
Jacketing: Life-Cycle Assessments
for Selected Applications
Summary
This summary document is based on information presented in the EPA Design for the
Environment project report, Wire and Cable Insulation and Jacketing: Life-Cycle
/Assessments for Selected Applications. Some information in the life-cycle
assessment report was provided by individual technology vendors and has not been
independently corroborated by EPA. The identification of specific products or
processes in this document is not intended to represent an endorsement by EPA or
the U.S. Government. This summary document has not been through a formal
external peer review process.
US. ERA
-------
ACKNOWLEDGEMENTS
This life-cycle assessment (LCA) summary was prepared for the U.S. Environmental
Protection Agency's (EPA's) Design for the Environment (DfE) Wire and Cable
Partnership by Abt Associates Inc., under contract #68-W02-077. This document is
based primarily on the full project report, Wire and Cable Insulation and Jacketing:
Life-Cycle Assessments for Selected Applications, prepared by Maria LeetSocolof,
Jay Smith, David Cooper, and Shanika Amarakoon, under funding from the U.S.
Environmental Protection Agency's DfE Program in the Economics, Exposure, and
Technology Division (EETD) of the Office of Pollution Prevention and Toxics (OPPT).
This LCA study was conducted as part of the DfE Wire and Cable Partnership, under
the direction of the project's Core Group members, including Kathy Hart, Project Co-
Chair, U.S. EPA OPPT, DfE Branch; Liz Harriman, Project Co-Chair, Toxics Use
Reduction Institute, University of Massachusetts Lowell; Maria LeetSocolof, David
Cooper, Jay Smith, Shanika Amarakoon, Christopher Guyol, and Brian Segal, Abt
Associates Inc.; Susan Landry, Albemarle Corporation; Dave Kiddoo, Gary Nedelman,
and Troy Brantley, AlphaGary Corporation; Charlie Glew, Cable Components Group,
LLC; Joe Daversa, Chemson, Inc.; Rob Wessels, CommScope; Ralph Werling and Gary
Stanitis, Daikin America, Inc.; Stacy Cashin and James Hoover, DuPont; Fred Dawson,
DuPont Canada; Brenda Hollo and Paul Kroushl, Ferro Corporation; Dr. Henry Harris,
Georgia Gulf; AkshayTrivedi, Judd Wire; Richard Shine, Manitoba Corporation; Richard
LaLumondier, National Electrical Manufacturers Association (NEMA);Tim Greiner,
Pure Strategies, Inc.; J. Brian McDonald, SGS-US Testing-CTS; Melissa Hockstad,
Society of the Plastics Industry (SPI); Paul Sims, Southwire Company; Stefan Richter,
Sud-Chemie, Inc; Dr. Jim Tyler, Superior Essex; Mike Patel, Chuck Hoover, and David
Yopak, Teknor Apex Company; Scott MacLeod and Steve Galan, Underwriters
Laboratories; HJ. (Bud) Hall and Frank Borrelli, Vinyl Institute of the American Plastics
Council.
The authors gratefully acknowledge the contributions of James Murphy and of the late
J. Vincent Nabholz of EPA's Risk Assessment Division, OPPT. Their assistance in
reviewing and providing health and environmental toxicity information for the project
was greatly appreciated.
The authors would like to acknowledge the outstanding contributions of the Abt
Associates staff who assisted the authors, including Alice Tome for her technical
quality review; and Van Smith, Emily Connor, Kavita Macleod, and Sue Greco for their
technical support.
-------
CONTENTS
Introduction.
Question 1:
What is a life-cycle assessment?.
Question 2:
Which wire and cable products were investigated during the project? 4
Question 3:
How were environmental and health impacts evaluated? 6
Question 4:
How was uncertainty in the wire and cable life cycle addressed? 10
Question 5:
What are the health and environmental impacts of baseline, lead-free, and
zero-halogen CMR cables, and what drives the impacts? 12
Question 6:
What are the health and environmental impacts of baseline and lead-free
CMP cables, and what drives the impacts? 20
Question 7:
What are the health and environmental impacts of baseline and lead-free
NM-B cables, and what drives the impacts? 27
Question 8
Overall, where are the greatest potential health and environmental
impacts? 33
Question 9:
What are the limitations of the study?.
.37
Question 10:
What can wire and cable suppliers, manufacturers, and waste managers
do to reduce environmental impacts? 40
-------
INTRODUCTION
Purpose and Scoe of the Study
The purpose of the Wire and Cable Partnership was to evaluate the life-cycle
environmental impacts of standard (leaded) and alternative (lead-free and/or zero-
halogen) cable insulation and jacketing formulations for three cable types (CMR, CMP,
and NM-B) using the life-cycle assessment (LCA) approach. LCAs, which are generally
global and non-site specific in scope, look at the full life cycle of the product being
evaluated, from materials acquisition to manufacturing, use, and end-of-life (i.e., final
disposition). The WCP LCA considers 14 impact categories, which are related to
material consumption, energy use, air resources, water resources, landfills, and
human and ecological toxicity.
Need for the Study
The wire and cable industry manufactures a wide range of products that support a
multitude of applications. Many wire insulation and cable jacketing compositions
contain materials, such as lead, halogenated compounds, and other ingredients, that
impart electrical insulation and fire performance properties, but that have been
identified as materials of potential environmental concern or as materials for which
industry stakeholders have expressed a desire to identify and evaluate various
alternatives. The DfE/TURI Partnership has generated information on the
environmental impacts of leaded (baseline) and alternative cable constructions in
order to help companies make environmentally sound product and material choices.
Although some changes have been made in certain wire and cable sectors, the WCP
believes that developing and providing sound environmental data using a life-cycle
assessment approach could assist those and other sectors to pursue environmentally
preferable cables. Because of the large quantity of cable put into commerce every
year, choosing environmentally preferable materials could have a broad impact on
public health and the environment. Quantitative environmental life-cycle analysis of
the baseline and alternative cable formulations is needed, given the current interest
in lead-free cables in the United States and halogen-free cable materials in certain
overseas markets, the potential environmental concerns that lead- and halogen-
containing additives pose, and the fact that the relative life-cycle environmental
impacts of these cable formulations have not yet been determined. This project
offers the opportunity to mitigate current and future risks by assisting the wire and
cable industry in identifying cable jacketing and wire insulation formulations that are
less toxic and that pose fewer risks over their life cycles, and identifying areas for
environmental improvement.
About EPA's Design for the
Environment Program
EPA's Office of Pollution
Prevention and Toxics
established the DfE Program
in 1992 to encourage
businesses to incorporate
environmental concerns into
their business decisions. DfE
industry projects are
cooperative, joint
partnerships with trade
associations, businesses,
public-interest groups, and
academia to assist
businesses in specific
industries to identify and
evaluate more
environ mentally sound
products, processes,
technologies, and
formulations. The DfE Wire
and Cable Partnership
consists of individual wire and
cable manufacturers, supply
chain members, trade
association members,
environmental researchers, a
state funded research and
assistance organization, and
EPA.
-------
Question 1:
What is a life-cycle assessment?
The DfE Wire and Cable Partnership (WCP) conducted this analysis of wire and cable
products using a life-cycle assessment (LCA) approach, which allows for a
comprehensive analysis of the environmental consequences of a product system over
its entire life. LCA, which is increasingly being used by industry, contains four major
steps:
1. Goal Definition and Scoping lays out why the LCA is being conducted, its
intended use, and the system or data categories to be studied.
2. Life-Cycle Inventory (LCI) involves quantifying inputs (e.g., raw materials and
fuel) and outputs (e.g., emissions, effluents, and products).
3. Life-Cycle Impact Assessment (LCIA) involves characterizing the effects of the
inputs and outputs (as identified in the life-cycle inventory step) on the
environment and human and ecological health.
4. Life-Cycle Interpretation analyzes major contributions, conducts sensitivity
analysis and uncertainty analyses as warranted, and presents conclusions.
This study presents results, but does not make recommendations as to
preferred products or specific material choices, which is left to the wire and
cable industry and others to complete. Using the results of this study;
however, opportunities for improvement are introduced.
In the LCI and LCIA steps, the inputs and outputs, and environmental impacts
associated with the product throughout its life are quantified and characterized for
each life-cycle stage: raw material extraction, materials processing, product
manufacturing, product use, and end-of-life. Each of these major stages of the
product life cycle is described in Figure 1.1.
-------
Figure 1.1 Life-Cycle Stages of Wire and Cable Evaluated in this Study
INPUTS LIFE-CYCLE STAGES OUTPUTS
Materials
Energy
Resources
RAW MATERIALS EXTRACTION / ACQUISITION (Upstream)
Activities related to the acquisition of natural resources, including mining
non-renewable material, harvesting biomass, and transporting raw
materials to processing facilities.
MATERIALS PROCESSING (Upstream)
Processing natural resources by reaction, separation, purification, and
alteration steps in preparation for the manufacturing stage; and
transporting processed materials to product manufacturing facilities.
PRODUCT MANUFACTURE
Processing materials to compound and extrude wire and cable.
PRODUCT USE, MAINTENANCE, REPAIR
Use of wire and cable in buildings and telecommunication applications.
FINAL DISPOSITION / END-OF-LIFE
At the end of their useful lives, the wires and cables are retired
individually or as part of other equipment or products. If the wire and
cable can feasibly be recycled, the cable can be transported to an
appropriate facility where the conductor can be separated from the
insulation for materials recovery. Materials that are not recoverable are
transported to appropriate facilities and treated (if required or necessary)
and/or disposed of.
Product System Boundary
Wastes
Products
-------
Question 2:
Which wire and cable products were
investigated during the project?
This project investigated baseline and alternative cable formulations within three
different types of wire and cable products: (1) Category 6 riser-rated communication
cable (CMR); (2) Category 6 plenum-rated communication cable (CMP); and (3) non-
metallic sheathed low-voltage power cable as used in building wire (NM-B). These
products were chosen by the project partners because together they (1) contain
materials common to many wire and cable applications, (2) typically contain materials
for which alternatives are being sought, and (3) represent a significant share of the
wire and cable market. In particular, this report focuses on lead-stabilized and lead-
free cable constructions within each product type. For CMR, a zero-halogen cable
also was examined, though the limited available data only allowed for a partial cradle-
to-gate assessment.
A typical cable product consists of a wire conductor (typically copper) covered by
insulation, and a jacket that encases the insulated wire(s). The resins used for the
insulation of NM-B and for the jacketing of CMR, CMP, and NM-B cables are
compounded with other materials, such as heat stabilizers and flame retardants, in
order to meet performance specifications.
The goal of the WCP was to evaluate as many lead-free and halogen-free cables as
possible for each of the three cable types. Project partners assisted in identifying the
baseline and alternative cable constructions for the three different cable products.
Table 2.1 lists the general characteristics and makeup of each cable type.
Functional Unit
In an LCA, product systems are evaluated on a functionally equivalent basis. The
functional unit normalizes data based on equivalent use to provide a reference for
relating process inputs and outputs to the inventory and impact assessment across
cables. The product systems evaluated in this project are baseline (i.e., leaded) and
alternative (i.e., lead-free and zero-halogen) cable wire insulation and cable jacketing
formulations, as used in telecommunication and low-voltage power cable installations
in the United States. Each of the three cable types was evaluated in separate
-------
analyses, as each type has a different functionality. The functional unit for each cable
type is the insulation and jacketing used in a linear length of cable (one kilometer),
which would be used to transmit a signal that meets Underwriters Laboratories (UL)
performance requirements and fire safety specifications for each product type.
Table 2.1
Insulation and Jacketing Resins for Each Cable Evaluated in the WCP
Insulation resin
Jacketing base resin
Jacketing base
stabilizer material(s)
Baseline
HDPE:I
PVCC
Lead
CMR
Lead-free
HOPE3
PVC=
Calcium/
zirc
Zero-halogen
HDPEb
non-PVC6
non-Pb6
Baseline
FEPd
PVC=
Lead
CMP
Lead-free
PEP"
PVC:
Ca c'un/
zirc
Nl
Baseline
PVCC
PV(J:
Lead
Vl-B
Lead-free
PVC=
PVCC
Calcium/
zinc
= CV1R and CMP wire conductors are unshielded twisted pairs. 8 conductors in 4 pairs of equal gauge bare copper: NM-B wire
conductors are 12-gauge. 2-conductor copper with ground wire.
b High-density polyethylene.
oPolyvinyl chloride (PVC) is compounded with various additives, including heat stabilizers and flame retardants.
a Fluorinated ethylene propylene (FEP). a perfluoropolymer, is a copolymer of tetrafluoro-ethylene (TFE) and hexafluoro-
propylene. The most commonly used perfluoropolymer insulators in CMP cable are FEP and MFA (a copolymer of TFE and
perfluoro-methylvinyl-ether); however, the research in this study is based on FEP-insulated cables only.
- Proprietary.
-------
Question 3:
How were environmental and health
impacts evaluated?
The life-cycle environmental and health impacts of wires and cables were evaluated
through two sequential phases: (1) life-cycle inventory and (2) life-cycle impact
assessment.
Life-Cycle Inventory (LCI)
The LCI tallies the material and energy inputs and the environmental releases
(collectively referred to as "flows") throughout the products' life cycles. Given the
enormous amount of data involved in creating an inventory of all of the input and
output flows for a product system, decision rules were used to determine which cable
materials would be included as entire upstream processes. The decision rule process
began by assessing the materials used in cable production for the following attributes:
• The mass contribution of each material. With a greater mass of materials
and resources consumed, the potential for a material to have a significant
environmental impact increases.
• Materials that are of known or suspected environmental significance (e.g.,
toxic). To the extent feasible, the process considers materials or components
known or suspected to exhibit an environmental hazard.
• Materials known or suspected to have a large contribution to the system's
energy requirements. Because many environmental impacts can be
associated with energy consumption, priorities were given to including
materials or processes that are known or suspected to consume large
amounts of energy.
• Materials which are physically or functionally unique to one cable formulation
over another. The physical or functional uniqueness of a material or
component could be identified by chemical makeup or by size.
Attempts were made to include all materials greater than five percent by weight.
Materials between one percent and five percent by mass were subject to inclusion
based on other decision rules or data availability. Materials of known or suspected
environmental or energy significance were also included, regardless of their mass
contribution. Materials that are physically or functionally unique to a cable product
compared to the baseline (leaded) construction, as determined by the Core Group,
-------
Figure 3.1. Criteria for Selecting Inputs
MATERIAL/COMPONENT INPUTS:
• >5% of total mass
1 environmental concern
• energy concern
• functionally significant
• physically unique
• 1-5% of total mass
<1% of total mass
• not otherwise
significant or
•unique*
Excluded from
analysis
'For example, materials are excluded if they are not of known environmental significance
or not physically unique.
are also considered if they would have been otherwise eliminated based on the mass
cutoff. Figure 3.1 is a graphical representation of these decision rules.
In considering upstream materials, in addition to applying the decision rules, a
combination of other factors was also considered, including availability of existing
data and manufacturers' willingness to participate. When an inventory of a
production process for a material identified by the decision rules could not be
obtained, the material still remained in the inventory for the cable (what is not
included are all the flows associated with producing that material).
Based on the LCI data obtained for this study, 2 of the 4 analyses were based on the
full life cycle: materials extraction ("upstream"), manufacturing, and end-of-life (EOL)
stages. The remaining 2 analyses were based on only upstream and manufacturing
stages:
• Full life cycle
• Leaded and lead-free CMR Category 6 insulation and jacketing
• Leaded and lead-free CMP Category 6 insulation and jacketing
• Partial life cycle
• Leaded and lead-free vs. zero-halogen CMR Category 6 insulation and
jacketing.
• Leaded and lead-free NM-B power cable insulation and jacketing
The processes included in the full life-cycle analyses are presented in Figure 3.2. The
processes in the partial life-cycle analyses are a subset of processes shown for the
full life cycles.
Life-Cycle Impact Assessment (LCIA)
-------
Figure 3.2 Generic Process Flows for All Cables Evaluated in the WCP
Materials extraction and processing
(3
Polyvinyl chloride
Phthalate piasticizers
Aluminum hydroxide
Calcinated clay
Tribasie lead sulfate
Limestone
High density polyethylene
Dibasic lead phtha'ate
Ca;Zn stabilizer
Polyolefin
Fkiorinated ethylene propylene
Electricity
Light fuel oil (#2)
Heavy fuel oil (S6)
Natural gas
Nitrogen
Low density polyethylene
Antimony trioxide
Manufacturing
Insulation/jacket
4 compounding^
/ 1
j Insulation &
I ^ jacketing
\ extrusion
V t
I
Crossweb
Extrusion
Installation/use
Cable \l/r
E nd-ol-lile '
Building fire
Regulated
incineration
Landfill ing
Cablo
chopping
*
Thermoplastics
recycling
a Only included for CMR and CMP.
Specific material and energy processes vary depending on the cable alternative and which downstream process they feed Into, Listed here
are all the materials for baseline and alternative cable constructions of each cable type: CMR, CMP and NM-B.
Insulation compounding is only applicable to NM-B cables in this study.
Bold processes indicate primary data collected.
The LCIA is the process by which the environmental burdens identified in the LCI are
translated into environmental impacts. It is important to note that direct comparisons
cannot be made across impact categories, because impacts in different impact
categories are generally calculated based on different scales. The WCP LCIA
consisted of two steps: classification and characterization.
Classification - The process of assigning and aggregating data from inventory studies
to impact categories. The WCP LCA places inventory data into one or more of 14
impact categories. These categories cover a range of effects that address natural
resources impacts, abiotic ecosystem impacts, and human health and ecotoxicity.
Characterization - The characterization step of LCIA includes the conversion and
aggregation of LCI results to common units within an impact category. Different
assessment tools are used to quantify the magnitude of potential impacts, depending
on the impact category. Three types of approaches are used in the characterization
method for the WCP:
• Loading - An impact score is based on the inventory amount.
• Equivalency - An impact score is based on the inventory amount weighed by
a certain effect, equivalent to a reference chemical.
• Scoring of inherent properties - An impact score is based on the inventory
-------
amount weighed by a score representing a certain effect for a specific
material (e.g., toxicity impacts are weighed using a toxicity scoring method).
Table 3.1 presents the 14 impact categories and a description of how each was
calculated.
Table 3.1
Inventory Types and Properties for Classifying Inventory Items into Impact Categories
Impact Category
Input
Inventory Properties
Output Chemical/Material Properties
Natural Resource Impacts
Non-renewable resource
use/depletion
Energy use
Landfill space use (volume)
Material.
Electricity,
N/A
fuel N/A Non-renewable
fuel N/A Energy
waste to Solid, hazardous, and radioactive
| landfill waste
Abiotic Ecosystem Impacts
G oha warning
Stratospheric ozone depletion
Photochemical smog
Acidification
Air particulates
Water eutrophication (nutrient
enrichment)
N/A
t^ N/A
N/A
N/A
^^ N/A
N/A
Air Global warming gases
| Air Ozone depleting substances
Substances that can he
photochemically oxidized
Substances that react to form
Air
_| hydrogen ions (H-)
1 Air Air particulates (PM 10. TSP)a
Substances that contain available
Water
nitrogen or phosphorus
Human Health and Ecotoxicity
Carcinogenic human health
effects - occupational
Carcinogenic human health
effects - public
Chronic, non-carcinogenic
human health effects -
occupational
Ch ronic. non-carci n ogeni c
human health effects - public
(and terrestrial ecotoxicity)
Aquatic ecotoxicity
Material
N/A
Material
N/A
N/A
.,,. Toxic material (carcinogenic)
.. Toxic material (carcinoeenici
Air. soil, water
Toxic material (non-carcinogenic)
N/A
Toxic material (non-carcinogenic)
Air, soil, water
Water Toxic material
"Acronyms: participate matter with average aerodynamic diameter less thar 10 micrometers (PM10); total
suspended participates (TSP).
N/A=not applicable.
-------
Question 4:
How was uncertainty in the wire and cable
life cycle addressed?
Uncertainty Analysis
Four parameters within the life-cycle processes of the CMP and CMR cables were
considered to be highly uncertain and were modeled as uniform distributions, using
Monte Carlo statistical methods. These uncertainties only applied to the CMR and
CMP analyses where the full life cycle was evaluated and where there was a large
discrepancy in the extrusion energy data. The first three parameters below are from
the EOL stage and the fourth is from the manufacturing stage.
• Cable consumed in fire - The parameter representing the percentage of
cable consumed in fire was selected as highly uncertain due to the lack of
information about building cable burned in fire. The frequency of fires in
buildings containing the cables of interest was well characterized, and the
natural extreme bounds were that anywhere from 0% to 100% of the cable
contained in these buildings would burn in the fire (equivalent to 0-1.1% of all
cable installed). However, we chose 10% of cables that burn in a structure fire
as a central estimate because fire protection methods would skew actual burn
percentages toward the lower end, and bounded the distribution at 0 and
20%.
• Proportion of cable to recycling - The percentage of cable insulation and
jacketing resins going to recycling was another source of substantial
uncertainty in the EOL stage. Using an upper estimate based on data from
Europe (20% of recovered wire and cable resins are recycled), a range of 0%
to 20% of the cable resins was modeled as being recycled.
• Proportion of lead leached from landfills - The parameter representing the
percentage of lead leached into the ground assumed that 0-100% of the
leachate would ultimately escape any landfill lining and leachate collection
system (equivalent to 0-1.5% of total lead escaping for cable directly
landfilled, or equivalent to 0-10% of total lead escaping for cable resins
landfilled after chopping—a process that is used to recover the copper
conductor).
• Extrusion energy - Inconsistent and highly divergent inter-company energy
-------
values led to high uncertainty in the cable extrusion energy data. Thus, the
range of the data sets collected as primary data for the lead-free cable were
used to set the bounds of the uncertainty analysis, given that none of the data
could be identified as anomalous. Because the baseline cable pulled
energy use values from only one data set, a proxy data set that produced an
equivalent uncertainty range in extrusion energy use was incorporated. A
uniform distribution was used to bound the energy used in the baseline and
lead-free cable extrusion inventories.
Sensitivity Analysis
The uncertainty of impact category results was a result of the concurrent variation of
the four parameters. Therefore, a sensitivity analysis was necessary to assess the
magnitude of each parameter's contribution. A built-in sensitivity analysis function
from the GaBi4 LCA software was used to determine the amount of variance in each
impact category attributable to each of the dynamic parameters.
11
-------
Question 5:
What are the health and environmental
impacts of baseline, lead-free, and zero-
halogen CMR cables, and what drives the
impacts?
This section presents the results for each impact category described in Question 3 for
CMR cable. Although some LCAs assign importance ranks or weights to impact
categories, this LCA does not, because ranking impact categories requires subjective
choices that may not be appropriate for all stakeholders. The major focus was on the
full life-cycle impacts of the baseline (lead-stabilized) cable and lead-free cable. A
less comprehensive analysis was undertaken in the case of the partial life-cycle (or
cradle-to-gate) impacts among the baseline, lead-free, and zero-halogen cables. Due
to a lack of data, only the upstream energy use and resin production were modeled
for the three cable types in the zero-halogen case.
Full Life Cycle: Baseline and Lead-Free
For each impact category, Table 5.1 presents life-cycle impact indicator scores for the
baseline cable and the lead-free cable, the percent difference between the two
cables, a data quality rating, and an indication of possible significance. Highlights
from the results are as follows:
• The baseline cable had the greatest environmental burden (negative percent
change) in 8 impact categories, 2 of which may be statistically significant.
• The lead-free cable had the greatest environmental burden (positive percent
change) in 6 impact categories, 2 of which may be statistically significant.
• All 4 potentially significant differences were for toxicity impact categories.
• The 2 largest absolute percent changes (potential public non-cancer and
potential aquatic ecotoxicity) are statistically significant, and showed a greater
environmental burden for the baseline cable.
Figures 5.1 and 5.2 show the relative differences between baseline and lead-free
12
-------
Table 5.1
CMR LCIA Results
Impact Category
NRR
Energy
Landfill space
Global warming
Ozone depletion
Smog
Acidification
Air particulates
Eutrophication
Pot. occ. noncancer
Pot. occ. cancer
Pot. public noncancer
Pot. public cancer
Pot. aq. ecotox
- Full Life Cycle: Baseline and Lead-free.
Units per km Cable
kg
Ml
m3
kgC02-equiv.
kg CFG ll-equiv.
kg ethene-equiv.
kgS02-equiv.
kg
kg phosphate-equiv.
kg noncancertox-equiv.
kgcancertox-equiv.
kg noncancertox-equiv.
kgcancertox-equiv.
kgaqtox-equiv.
Baseline
Impact
Indicator
14?
2070
0.0166
90.3
5.91E-06
0.125
0-731
0-0782
0.00902
71.8
3.53
1460
0.834
17.5
Pb-free
Impact
Indicator
121
1970
0.0181
83.5
4.95E-06
0.134
0.678
0.0815
(1.00756
77.6
3.69
279
0.837
0.113
Percent
Change
-15%
- 3 :' :•
9%
-8%
-16%
7%
-7%
4%
-16%
8%
5%
-81%
0.3%
-99%
Possible
Quality Signif.
Rating Diff.a
M
M
M
M
L
M
M
M
M
M Y
M-L Y
M Y
M-L
M Y
8 "Y" indicates the cables were sign if icantly different at 80% confidence (this confidence interval was used because it was
part of a built-in program in GaBi4. the LCA software used for this project).
NRR = non-renewable resource use: Pot. = potential; occ. = occupational: aq. ecotox = aquatic ecotoxicity.
NOTE: Bold indicates the cable with the greatest environmental burder 'within an impact category.
cables within the 14 environmental and human health impact categories presented in
Table 5.1. The values in Figures 5.1 and 5.2 are the log of the ratio of the baseline
cable impact score to that of the lead-free cable impact score. Positive log ratios
indicate greater environmental burden for the baseline cable, and negative log ratios
indicate greater environmental burden for the lead-free cable. Note that relative
differences should only be examined within and not across impact categories
because there is no association between relative differences in one category
compared to that of another. Further, the relative differences depicted for each
impact category are not normalized to indicate any significance of the impacts
themselves; they only show the relative difference between the baseline and
alternative cables.
13
-------
Figure 5.1 Relative CMR Impacts: Baseline and Lead-free
V
-C
Q.
' rr
oi J£
•O re
re >
in =
E «
o u
US Q)
*j -o
o C
I o
E o
*o §
o 2L
43
OA
n ^ -
n 9 -
n 1 -
09 _
n A
T
A
\
<
I
D
» I
t * *
-
<
>
*•
y j f S f t i
^
^
4
T
--? fl" j?
$• ^" ^J
- / /
1 / / s f / / / / / / /
/ o / /
NOTE: Log ratio > 0 indicates greater environmental burden for baseline cable;
do not compare across impact categories.
Figure 5.2 Relative CMR Impacts: Baseline and Lead-free
(Public Non-cancer and Ecotoxicity)
£ 3^
- J
a
1-25-
•3 n
n >
^, L, -
a u 1 5 -
u e
w u
T) I 1 -
^ =
0. D
C
'B o
o L
*: n _
0
- .
t
1
k
•v (V~
S ^ &
z * ^
f
NOTE: Log ratio > 0 indicates greater environmental burden
for baseline cable; do not compare across impact categories.
14
-------
Which Processes Drive the Impact Scores?
A summary of the top contributing processes and material flows (i.e., input or output)
for baseline and lead-free cables by impact category is presented in Table 5.2.
• For the baseline cable, electricity generation is the top contributing process
for 6 of the 14 impact categories.
• For the lead-free cable, electricity generation is the top contributing process
for 8 of the 14 impact categories.
Table 5.2
CMRSummaryof Top Contributors to LCIA Results -Full Life Cycle: Baseline and Lead-free.
Baseline
Impact Category
t\RR
Energy
Landfill space
Global warming
Ozone depletion
Smog
Acidification
Air partial at es
Eut rap hi cat ion
Pot. occ.
noncancer
Pot. occ cancer
Pot. public
noncancer
Pot. public cancer
Pot. aq. ecotox
Top Process
Elect li city generation
Electricity1 gene ration
MSW landfill
Electricity1 gene ration
Electricity generation
Jacketing resin
production
Electricity generation
Jacketing resin
production
Electricity generation
Jacketing
compounding
Jacketing
compounding
MSW landfill
Jacketing resin
production
MSW landfill
Top Flow
Inert rock
Natural gas
PVC waste
Carbon dioxide
CFC-11
VOC (unspecified)
Su fur dioxide
Gust
Cnerrical oxygen
demand
FR#2 (non-halogen)
Phttialates'
Lead (water)
Ntrogen oxides (air)*
Lead
Pb-free
Top Process
Electricity generation
Electricity1 generation
MSWIandfil
Bectrfcity1 generation
Bectricity generation
Jacketing resh
production
Bectrtity generation
Jacketing resh
production
Bectrfcity generation
Ja cketin g
corrpounding
Ja cketin g
conrpounding
Bectrfcity generation
Jacketing resh
production
Bectrfcity generation
Top low
Inert rock
Natural gas
PVC waste
Carbon dbxide
CFC-11
VOC (unspecified)
Sulfur doxide
Dust
Chemical oxygen
demand
FR #2 (non-
halogen)
Phtha'ates'
Sulfur doxide (air)
Nitrogen oxides
(air)*
Chbrre Dissolve d)
N RR = non-renewable resource use; Pot = potente!; On. = occupational; Aq. Ecotox = aquatb ecctoxbity; PVC = po^vin>1
chloride; MSW = municipal s did waste; CFC = chlorofluorocarbon; VOC = vobtile organic compound; FR = flam e retardant.
*Fbws given default tox city1 hazard v a Les due to lade of toxi cdog i ca I d ata.
15
-------
Natural Resource Impacts
Non-renewable resource use/depletion: Non-renewable natural resources are
typically abiotic materials, such as mineral ore or fossil fuels. For both the baseline
and lead-free cables, electricity generation contributes more than any other process
to the non-renewable resource use impact category. Electricity generation contributes
74% of the total non-renewable resource use impact for the baseline cable and 71%
for the lead-free cable. Inert rock is the top contributing material input flow for both
cables, representing 60% of the impact for the baseline cable and 57% for the lead-
free cable.
Energy use: Energy use impact scores are the sum of electrical and fuel energy
inputs. The generation of electricity drives the impact for both baseline and lead-free
cables, contributing 37% and 32% of the total energy use impact, respectively.
Natural gas is the top contributing material flow for both cables, representing 29% of
the impact for the baseline cable and 31% for the lead-free cable.
Landfill space use: Landfill space use impacts are calculated based on the volume of
landfill space consumed by solid, hazardous, and/or radioactive waste. The
municipal solid waste landfilling process dominates landfill space use impacts,
contributing 76% of the total impact for both baseline and lead-free cables. PVC
waste is the top contributing material flow for both cables, representing 46% of the
impact for each cable.
Abiotic Ecosystem Impacts
Global warming: The impact scores for the effects of global warming and climate
change are calculated using the mass of a global warming gas released to air,
modified by a global warming potential equivalency factor. The generation of
electricity drives this impact category, contributing 56% of the total impact for the
baseline cable, and 50% for the lead-free cable. Electricity generation produces
considerable amounts of carbon dioxide, a global warming gas. Carbon dioxide is the
top contributing material flow for both cables, representing 85% of the impact for the
baseline cable and 83% for the lead-free cable.
Stratospheric ozone depletion: Ozone depletion impact scores are based on the
identity and amount of ozone-depleting chemicals that are released to air. Electricity
generation contributes 97% of the total impact for the baseline cable, and 95% for the
lead-free cable. CFC-11 is the top contributing material flow for both cables,
representing 44% of the impact for the baseline cable and 43% for the lead-free
cable.
-------
Photochemical smog: Photochemical smog refers to the release of chemicals that
may react with sunlight in the atmosphere to produce photochemical oxidants, such
as tropospheric ozone. The production of jacketing resin is the top contributor to the
photochemical smog impact for both baseline and lead-free cables, contributing 45%
and 50%, respectively, to the total impact. Unspecified volatile organic compounds
(VOCs) are the top contributing material flow for both cables, representing 70% of the
impact for the baseline cable and 74% for the lead-free cable.
Acidification: Acidification impacts refer to the release of chemicals that may
contribute to the formation of acid precipitation. The generation of electricity drives
the acidification impact, contributing 56% and 49% of the total impact for baseline
and lead-free cables, respectively. Sulfur dioxide is the top contributing material flow
for both cables, representing 63% of the impact for the baseline cable and 60% for
the lead-free cable.
Air particulates: Air particulate impacts are based on the amount of particulate
matter with an average aerodynamic diameter less than 10 micrometers (PM10) that
is released to the air. Jacketing resin production drives the air particulates impact,
contributing 37% and 42% of the total impact for baseline and lead-free cables,
respectively. Dust is the top contributing material flow for both cables, representing
99% of the impact for the baseline cable and 98% for the lead-free cable.
Water eutrophication (nutrient enrichment): Eutrophication (nutrient enrichment)
impacts to water are based on the identity and concentrations of eutrophication
chemicals released to surface water after treatment. The generation of electricity
drives the total impact, contributing 91% and 89% of the total impact for baseline and
lead-free cables, respectively. Chemical oxygen demand is the top contributing
material flow for both cables, representing 94% of the impact for the baseline cable
and 93% for the lead-free cable.
Human Health and Ecotoxicity
Occupational health - potential non-cancer toxicity: Occupational impact scores are
based on the potential toxicity of material inputs to each process. This
characterization method does not necessarily indicate where actual exposure is
occurring. Instead, it uses the inputs of potentially toxic materials as surrogates for
exposure. The materials used during jacketing compounding drive potential non-
cancer occupational health impacts, contributing 93% and 94% of the total impact for
baseline and lead-free cables, respectively. A non-halogen flame retardant
-------
(proprietary) is the top contributing material flow for both cables, representing 89% of
the impact for the baseline cable and 91% for the lead-free cable.
Occupational health - potential cancer toxicity: Materials used during jacketing
compounding drive potential cancer occupational health impacts, contributing 95%
and 84% to the total impact of baseline and lead-free cables, respectively.
Unspecified phthalates are the top contributing material flow for both cables,
representing 64% of the impact for the baseline cable and 62% for the lead-free
cable. Unspecified phthalates, as a group, do not have specific toxicological data and
therefore are characterized by a default toxicity hazard value, which assumes the
toxicity is equivalent to the geometric mean of all chemicals used to determine the
relative toxicity.
Public health - potential non-cancer toxicity: Impact scores are calculated based on
the identity and amount of toxic chemical outputs with dispositions to air, soil, and
water. Inventory items do not truly represent long-term exposure. Instead, impacts
are relative toxicity weightings of the inventory. For the baseline cable, releases from
landfilling municipal solid wastes are the greatest single contributor to potential non-
cancer public health impacts, contributing 59% of the total impact. For the lead-free
cable, emissions during electricity generation are the greatest single contributors to
potential non-cancer public health impacts, contributing 58% of the total impact.
Lead in water is the top contributing material flow for the baseline cable, representing
74% of the total impact. Sulfur dioxide is the top contributing material flow for the
lead-free cable, representing 99% of the total impact.
Public health - potential cancer toxicity: Emissions from jacketing resin production
drive the impact score for both baseline and lead-free cables. Jacketing resin
production contributes 37% of the total impact for baseline cable, and 44% for lead-
free cable. Nitrogen oxides (NOx) are the top contributing material flow for both
cables, representing 41% of the impact for the baseline cable and 40% for the lead-
free cable. NOx are characterized by a default toxicity hazard value.
Potential aquatic ecotoxicity: Potential aquatic ecotoxicity impacts refer to the effects
of chemical outputs on non-human living organisms in freshwater aquatic
ecosystems. Emissions from landfilling municipal solid wastes drive aquatic
ecotoxicity impacts for baseline cables, contributing 79% of the total impact.
Emissions from electricity generation drive potential aquatic ecotoxicity impacts for
lead-free cables, contributing 77% of the total impact. Lead in water is the top
-------
contributing material flow for the baseline cable, representing 99% of the total
impact. Dissolved chlorine is the top contributing material flow for the lead-free
cable, representing 97% of the total impact.
Partial Life Cycle 3-Way Analysis: Baseline, Lead-Free, and Zero-Halogen
The 3-way CMR analysis (baseline versus lead-free versus zero-halogen)
demonstrated that within the cradle-to-gate analysis, the zero-halogen cable used far
more energy than the baseline or lead-free cable. This was a function of more energy
required per mass of compounded resin produced, as well as the zero-halogen cable
having a higher mass to length ratio. Thus, on a functional unit basis, the total energy
requirement was much larger (quantities withheld for proprietary considerations). In
the CMR 3-way results, the production of electricity drove most impact categories,
except for landfill space use and potential occupational non-cancer and cancer
toxicity, for which the jacketing process was the top contributor. For air particulate
production, the lead and lead-free cables were driven by jacketing compounding, but
the zero-halogen was driven by electricity production. Note that the robustness of
these data is limited, as the zero-halogen data are only based on one company's
data. Further, this analysis does not provide full life-cycle information and should not
be construed to represent full life-cycle impacts.
These results also demonstrate that limiting the focus to a few manufacturing
processes, even on a functionally equivalent basis, does not adequately estimate
impacts over the full life cycle. This is evidenced by comparing the full CMR life-cycle
analysis with the partial life-cycle analysis, which only takes into consideration
jacketing compounding and associated energy. In the full life-cycle analysis, the lead-
free cable had lower impact indicators than the baseline in 8 impact categories;
however, for the partial analysis, only 1 category had lower impact indicators for the
lead-free cable. Of the 5 categories in the full life-cycle analysis that had the greatest
likelihood of statistically significant differences, 3 had results reversed in the partial
life cycle (i.e., significantly less burden in the full life cycle versus more burden in the
partial life cycle or vice versa): potential occupational cancer toxicity, potential public
non-cancer toxicity, and potential aquatic ecotoxicity.
19
-------
Question 6:
What are the health and environmental
impacts of baseline and lead-free CMP
cables, and what drives the impacts?
This section presents the results for each impact category described in Question 3 for
CMP cable. Although some LCAs assign importance ranks or weights to impact
categories, this LCA does not, because ranking impact categories requires subjective
choices that might not be appropriate for all stakeholders.
For each impact category, Table 6.1 presents life-cycle impact indicator scores for the
baseline and lead-free cables, the percent difference between the two cables, a data
quality rating, and an indication of possible significance. Highlights from the results
are as follows:
• The baseline cable had a greater environmental burden (negative percent
change) for 12 impact categories, 4 of which may be statistically significant.
Table 6.1
CMP LCIA Results - FJI Lfe Cycle: Baseline and Lead-free
Impact Category
hRR
Energy
Landfill spare
Global "warming
Ozone depletion
Smog
Acidification
Air partial at es
Eutro phi cation
Pot. occ Noncancer'
Pot. occ Cancer"
Pot. public noncarcer
Pot. public cancer
Pot. aq. Ecotox
Units per kmCable
Kg
MJ
m3
kg C0;-equiv.
kg CFG 11-equiv.
kg ethene-equw.
kg S0;-equiv.
Kg
kg phosphate-equiv.
kg noncaicertox-equiv.
kg cancertox-equiv.
kg noncaicertox-equiv.
kg cancertox-equiv.
kg aqtox-equiv.
Baseline Pb-fiee
hip act Impact
Indicator Indicator
237
3770
0.0132
181
0.00116
0.0886
0.877
0.0746
0.0125
49.2
2.16
952
0.735
8.64
219
3570
0.0144
171
0.00110
0.0868
0.819
0.0726
0.0114
46.3
Z22
358
0.701
0.151
Percent
Change
-3%
5%
-5%
-5%
-2%
-7%
-3%
-9%
-5%
3%
-62%
-5%
-93%
Quality
Rating
M
M
M
M
L
M
M
M
M
M
M -L
M
M-L
M
Possible
Sgnrf.
Diff.«
Y
Y
Y
Y
Y
fl"Y" hdicatesthe cable weresignificanfy different at 30% confidence (this confbence interval was used because it was partcfa
built-in program in GaBft. the LCAs ofhvare usedforthfe projecty.
FEP production, which came from 2 primary datasets , was modeled with 2 industrial precurs or chemicals functioning as inputs;
production of PVC, the other major resin used inC MP cables, and which camef rom a secondary dataset, was modeled as if al of
the materials cane from ground (mining of inert or low-taxi city inputs i and did not expicrtly incLde industrial precue or chemicals . In
orderto bem ore coreistent across resins, the attributions from industrial precursor chemicals in the FEP supp^1 chah were
removeid prior to calculator of the potential occupatbnal towcity res ults.
NRR = non-renewable res ource use; Pot. = potential occ = occupatbnal; aq. ecctcx= aquatb ecz-tatidty.
NOTE: Boldindicstes the cabb with the highest impact inditHtor score (i.e.. greatest environmental burden) wthin an impact
category.
-------
• The lead-free cable had a greater environmental burden (positive percent
change) for 2 impact category, one of which is statistically significant.
• Of the 5 impact categories with potential statistical significance, 4 were
related to toxicity.
• The 2 largest absolute percent changes (potential public non-cancer and
potential aquatic ecotoxicity) were statistically significant, and show a greater
environmental burden for the baseline cable.
Figures 6.1 and 6.2 show the relative differences between baseline and lead-free
cables within the 14 environmental and human health impact categories presented in
Table 6.1. The values in Figures 6.1 and 6.2 are the log of the ratio of the baseline
cable impact score to that of the lead-free cable impact score. Positive log ratios
indicate greater environmental burden for the baseline cable, and negative log ratios
indicate greater environmental burden for the lead-free cable. Note that relative
differences should only be examined within and not across impact categories,
because there is no association between relative differences in one category
compared to that of another. Further, the relative differences depicted for each
impact category are not normalized to indicate any significance of the impacts
themselves; they only show the relative difference between the baseline and
alternative cables.
Figure 6.1 Relative CMP Impacts: Baseline and Lead-free
"° "uT no
•o ™
2 E 015-
ir = 0 1
C 0)
0 0
o c n 05 -
CO 0}
.4-1 "D
u c n -
Q- o
E U n ITS
•s
r r
^
2
tv
<
K
4
> * <
*
>• • ^
. .
>
J
/ / ^ •? .^J ^" ^ /
/ ,/ / ,/ / ^ -^ -^
^" -^ Ic ^5 if *j ^ ^- Cj
«f ° ^
^ CL ^
4
t
•^
"
^
I
Q C5. '^
<^ ^ 4?
i"
NOTE: Log ratio > 0 indicates greater environmental burden for baseline cable;
do not compare across impact categories.
-------
Figure 6.2 Relative CMP Impacts: Baseline and Lead-free
(Public Non-cancer and Ecotoxicity)
*_ i.O
a
a.
"O i — i ^
5 " t
If
O 1_
^-_. m -If:
— ^J I-O
in c
£ •;
s s 1 .
s =
o i
™ c n^
Is °-5
^g o-
">
••
o a °
! ? £
o cf ^3"^
O5 (b *•?
° ? ®
Which Processes Drive the Impact Scores?
A summary of the top contributing processes and material flows for baseline and
lead-free cables by impact category is presented in Table 6.2.
• For the baseline cable, both insulation and jacketing resin production are the
top contributing process for 3 of the 14 impact categories.
• For the lead-free cable, electricity generation is the top contributing processes
for 5 of the 14 impact categories.
Natural Resource Impacts
Non-renewable resource use/depletion: Non-renewable natural resources are
typically abiotic materials, such as mineral ore or fossil fuels. Electricity generation
drives non-renewable resource use impacts, contributing 65% and 64% of the total
impact for baseline and lead-free cables, respectively. Inert rock is the top
contributing material flow for both cables, representing 52% of the total impact for
each cable.
Energy use: Energy use impact scores are the sum of electrical and fuel energy
inputs. Electricity generation drives energy use impacts, contributing 29% and 28% of
the total impact for baseline and lead-free cables, respectively. Natural gas is the top
contributing material flow for both cables, representing 60% of the total impact for
each cable.
-------
Table 6.2
CMPSummary of Top Contributors to LCIA Results- Full Life Cycle Easelineand Lead-
free.
Impact Category
NRR
Energy
Landfill space
G 1 cb a 1 warning
Ozone depletion
Baseline
Top p rocess To p f 1 osv
Electricity generation
Insuldbn resin
production
MSW Ian dill
Insuldbn resin
production
Insuldbn resin
production
Smog Jacketing resin
production
Acidfication Electricity generation
Particulatematter J acketi ng res in
production
Eutrcphicaticn Electricity generation
Pot. occ. no nca nee r Natural gas product! on
Inert rock
Natural gas
PVCWaste
Carbon doxide
Refrigerant #5
VOC (unspecified}
Sulfur dioxide
DUSt
Chemical oxygen
demand
Natu^ gas*
Pb-free
Top Process T o p f low
Electricly generatbn
Insulation resin
production
MSWIandfil
Insulation resin
production
Insulation resin
production
Jacketing resin
production
Electricty generatbn
Jacketing resin
production
Electricly generatbn
Natural gas production
Inert rock
Natural gas
PVCWaste
Carbon dbxide
Refrigerant*
VOC (unspecified)
SUfur dioxide
Dust
Chemical oxygen
demand
Natural gas*
Pot. occ. cancer Jacketing compoundng Flame retard ant #3*
Pot. public MSWIandlll Lead(waer)
noncancer
Pot. public cancer Jacketing resin Nitrogen oxides (air)*
production
Pot, aq. e cotox M S W I an dfi 11 Lead
Jacketing compoundng Flame retardant#3*
Electricly generatbn SJfur dioxide (air)'
Jacketing resin Nitrogen oxides (air)*
production
Electricty generatbn Chbrine (dissolved)
NRR = non-enewabfe resource use; Pot. = potential; occ. = occupational aq.ecotrK = aquatic ecotoxi city; PVC = pdyvinyI chloride
MSW = municipal sold waste; HCFC = hydroohtar nfluorocar bon; VOC = volatile organic oompound.
*Flows given defaut tocidty hazard values due to lade of toxbologbaldate.
Landfill space use: Landfill space use impacts are calculated based on the volume of
landfill space consumed by solid, hazardous, and/or radioactive waste. The
municipal solid waste landfilling process drives landfill space use impacts,
contributing 66% and 69% of the total impact for baseline and lead-free cables,
respectively. PVC waste is the top contributing material flow for both cables,
representing 40% of the impact for the baseline cable and 42% for the lead-free
cable.
Abiotic Ecosystem Impacts
Global warming: The impact scores for the effects of global warming and climate
change are calculated using the mass of a global warming gas released to air,
modified by a global warming potential equivalency factor. For the baseline cable,
electricity generation drives global warming impacts, contributing 74% of the total
impact. For the lead-free cable, insulation resin production drives global warming
impacts, contributing 68% of the total impact. Carbon dioxide is the top contributing
material flow for both cables, representing 48% of the impact for the baseline cable
and 47% for the lead-free cable.
-------
Stratospheric ozone depletion: Ozone depletion impact scores are based on the
identity and amount of ozone depleting chemicals that are released to air. Insulation
resin production drives stratospheric ozone depletion impacts, contributing 88% and
87% of the total impact for baseline and lead-free cables, respectively. Refrigerant #5
is the top contributing material flow for both cables, representing 84% of the total
impact for each cable.
Photochemical smog: Photochemical smog refers to the release of chemicals that
may react with sunlight in the atmosphere to produce photochemical oxidants, such
as tropospheric ozone. Jacketing resin production drives photochemical smog
impacts, contributing 44% and 47% of the total impact for baseline and lead-free
cables, respectively. Unspecified volatile organic compounds (VOCs) are the top
contributing material flow for both cables, representing 43% of the impact for the
baseline cable and 45% for the lead-free cable.
Acidification: Acidification impacts refer to the release of chemicals that may
contribute to the formation of acid precipitation. Electricity generation drives
acidification impacts, contributing 68% and 66% of the total impact for baseline and
lead-free cables, respectively. Sulfur dioxide is the top contributing material flow for
both cables, representing 65% of the impact for the baseline cable and 64% for the
lead-free cable.
Air particulates: Air particulate impacts are based on the amount of particulate
matter with an average aerodynamic diameter less than 10 micrometers (PM10) that
is released to the air. Electricity generation drives air particulate impacts,
contributing 47% and 44% of the total impact for baseline and lead-free cables,
respectively. Dust is the top contributing material flow for both cables, representing
95% of the total impact for each cable.
Water eutrophication (nutrient enrichment): Eutrophication (nutrient enrichment)
impacts to water are based on the identity and concentrations of eutrophication
chemicals released to surface water after treatment. Electricity generation drives
eutrophication impacts, contributing 96% of the total impact for both baseline and
lead-free cables. Chemical oxygen demand is the top contributing material flow for
both cables, representing 95% of the impact for the baseline cable and 94% for the
lead-free cable.
24
-------
Human Health and Ecotoxicity
Occupational health - potential non-cancer: Occupational impact scores are based
on the potential toxicity of material inputs to each process. This characterization
method does not necessarily indicate where actual exposure is occurring. Instead, it
uses the inputs of potentially toxic materials as surrogates for exposure. Materials
used during natural gas production drive potential non-cancer occupational health
impacts, contributing 46% of the total impact for both baseline and lead-free cables.
Natural gas is the top contributing material flow for both cables, representing 48%
and 45% of the total impact for baseline and lead-free cables, respectively. Natural
gas is characterized by a default toxicity hazard value.
Occupational health - potential cancer: Materials used during cable jacketing
compounding drive potential cancer occupational health impacts, contributing 86%
and 84% of the total impact for baseline and lead-free cables, respectively. Flame
retardant #3, a proprietary material, is the top contributing material flow for both
cables, representing 28% of the impact for the baseline cable and 29% for the lead-
free cable. Flame retardant #3 is characterized by a default toxicity hazard value.
Public health - potential non-cancer: Impact scores are calculated based on the
identity and amount of toxic chemical outputs with dispositions to air, soil, and water.
Inventory items do not truly represent long-term exposure. Instead, impacts are
relative toxicity weightings of the inventory. For the baseline cable, emissions from
landfilling municipal solid waste drive potential non-cancer public health impacts,
contributing 44% of the total impact. For lead-free cables, electricity generation
drives potential non-cancer public health impacts, contributing 73% of the total
impact. Lead in water is the top contributing material flow for the baseline cable,
representing 56% of the total impact. Sulfur dioxide in air is the top contributing
material flow for the lead-free cable, representing 98% of the total impact.
Public health - potential cancer: Electricity generation drives potential cancer public
health impacts, contributing 44% and 42% of the total impact for baseline and lead-
free cables, respectively. Nitrogen oxides (NOx) are the top contributing material flow
for both cables, representing 44% of the total impact for each cable. Nitrogen oxides
are characterized by a default toxicity hazard value.
Potential aquatic ecotoxicity: Potential aquatic ecotoxicity impacts refer to the effects
of chemical outputs on non-human living organisms. For the baseline cable,
emissions from landfilling municipal solid waste drives potential aquatic ecotoxicity
-------
impacts, contributing 78% of the total impact. For the lead-free cable, emissions from
electricity generation drive potential aquatic ecotoxicity impacts, contributing 94% of
the total impact. Lead in water is the top contributing material flow for the baseline
cable, representing 98% of the total impact. Dissolved chlorine is the top contributing
material flow for the lead-free cable, representing 81% of the total impact.
26
-------
Question 7:
What are the health and environmental
impacts of baseline and lead-free NM-B
cables, and what drives the impacts?
This section presents the results for each impact category described in Question 3 for
NM-B cable. The cradle-to-gate analysis examined only part of the cable life cycle,
from material extraction to the compounding of the cable insulation and jacketing.
Cable manufacturing (extrusion) was excluded as project researchers were unable to
obtain a complete data set for this process. Subsequently, EOL could not be
adequately modeled, because the output from cable manufacturing (extrusion) to EOL
was not known. Although some LCAs assign importance ranks or weights to impact
categories, this LCA does not, because ranking impact categories requires subjective
choices that may not be appropriate for all stakeholders.
For each impact category, Table 7.1 presents life-cycle impact indicator scores for the
baseline and lead-free cables, the percent difference between the two cables, and a
data quality rating. Highlights from the results are as follows:
• The baseline cable has a greater environmental burden for 13 impact
categories (negative percent change).
• The lead-free cable has a greater environmental burden for 1 impact category
(positive percent change).
Table 7.1
NM-B Results - Partial Life Cycle: Baseline and Lead-Free
Impact Category
NRR
Energy
Landfill space
Global warming
Ozone depletion
Smog
Acidification
Air particulates
Entrophication
Pot. Occ. noncancer
Pot. Occ. cancer
Pot. Public noncancer
Pot. Public cancer
Pot. Af|. ecotox
Units per Km Cable
kg
Ml
m3
kgCC-2-equiv.
kg CFC 11-equiv.
kg ethene-equiv.
kgSCh-equiv.
kg
kg phosphate-equiv.
kg noncancertox-equiv.
kgcancertox-equiv
kg noncancertox-equiv.
kgcancertox-equiv.
kg aqtox-equiv.
Baseline
Impact
Indicator
70.6
1530
0.00251
52.2
9.79E-07
0.119
0.479
0.086?
0.00169
20.0
8.23
189
0.828
0.0894
Pb-free
Impact
Indicator
59.7
1440
0.00221
48.3
G.G1E-07
0.119
0.449
0.0759
0.00135
26.7
7.08
171
0.798
0.0626
Percent
Change
_ -,
-6% ~
-12%
-7%
-3 3%
0%
-6%
-12%
-21 >°/t
33%
-14%
-10%
-4%
-30%
Quality
Rating
M
M
M-L
M
L
M
M
M
M
M
M-L
M
M-L
M
NRR = non-renewable resource use; Pot. = potential; Occ. = occupational: Aq. Ecotox = aquatic ecotoxicity.
NOTE: Bold indicates the cable with the highest impact indicator score (i.e.. greatest environmental burden) within an
impact category.
-------
Figure 7.1 displays the relative differences between baseline and lead-free cables
within the 14 environmental and human health impact categories presented in Table
7.1. The values in Figure 7.1 are the log of the ratio of the baseline cable impact
score to that of the lead-free cable impact score. Positive log ratios indicate greater
environmental burden for the baseline cable, and negative log ratios indicate greater
environmental burden for the lead-free cable. Note that relative differences should
only be examined within and not across impact categories, because there is no
association between relative differences in one category compared to that of another.
Further, the relative differences depicted for each impact category are not normalized
to indicate any significance of the impacts themselves; they only show the relative
difference between the baseline and alternative cables.
Figure 7.1 Relative NM-B Impacts: Baseline and Lead-free (partial life cycle)
E -0.1
I
NOTE: Log ratio > 0 indicates greater environmental burden for baseline cable;
do not compare across impact categories.
Which Processes Drive the Impact Scores?
A summary of the top contributing processes and material flows (i.e., input or output)
for baseline and lead-free cables by impact category is presented in Table 7.2.
• For the baseline cable, jacketing resin production is the most frequent top
contributor to impact categories (8 of 14 categories).
• the lead-free cable, jacketing resin production is the most frequent top
contributor to impact categories (8 of 14 categories).
28
-------
Table 7.2
NM-B Siimmary of Top Contributors to LCIA Results - Partial Life Cycle: Baseline and
Lead-free.
Impact Category
NRR
Energy
Landfill space
Global warming
Ozone depletion
S rog
Acidification
Air partial lates
Eutrophication
Pot. Occ.
noncancer
Pot. Occ. cancer
Pot. P.ihlic
noncancer
Pot. Public cancer
Pot. Aq. ecotox
Baseline
Top process Top flow
Jacketing resin
production
Jacketing resin
production
Limestone production
Jacketing resin
production
Electricity generation
Jacketing resin
production
Jacketing resin
production
Jacketing resin
production
Electricity generation
Insulation
compounding
Jacketing
compounding
Jacketing resin
production
Jacketing resin
production
Plasticizer production
Inert rock
Natural gas
Treatment residue
(mineral)
Carbon dioxide
CFC-11
VOC (unspecified)
Sulfur dioxide
Dust
Chemical oxygen
demand
FR #2 (non-
halogen)
Plasticizer #2*
Sulfur dioxide lair;
Nitrogen oxides
(air)*
Copper (+1. +2)
Pb-free
Top Process Top flow
Jacketing resin
production
Jacketing resin
production
Limestone production
Jacketing resin
production
Electricity generation
Jacketing resin
production
Jacketing resin
production
Jacketing resin
production
Electricity generation
Insulation
compounding
Jacketing
compounding
Jacketing resin
production
Jacketing resin
production
Plasticizer production
Natural gas
Natural gas
Treatment residue
(mineral)
Carbon dioxide
CFC-11
VOC (unspecified)
Sulfur dioxide
Dust
Chemical oxygen
demand
FR #2 (non-halogen)
Phthalate plasticizer
so'
Sulfur dioxide (air)
VOC (unspecified)
(air)11
Copper (+1, +2)
t\RR = non-renewable resource use: Pot = potential; Occ. = occupational: Aq. ecotox = aquatic ecotoxicity: CFC =
chlorofluorocarbon: VOC = volatile organic compound: FR = flame retardart.
'Flows given default toxicity hazard Values due to lack of toxicological data.
Natural Resource Impacts
Non-renewable resource use/depletion: Non-renewable natural resources are
typically abiotic materials, such as mineral ore or fossil fuels. Jacketing resin
production drives non-renewable resource use and depletion, contributing 39% and
47% of the total impact for baseline and lead-free cables, respectively. Inert rock is
the top contributing material flow for the baseline cable, representing 22% of the total
impact. Natural gas is the top contributing material flow for the lead-free cable, also
representing 22% of the total impact.
Energy use: Energy use impact scores are the sum of electrical and fuel energy
inputs. Jacketing resin production drives energy use impacts, contributing 56% and
60% of the total impact for baseline and lead-free cables, respectively. Natural gas is
the top contributing material flow for both cables, representing 42% of the impact for
the baseline cable and 43% of the impact for the lead-free cable.
29
-------
Landfill space use: Landfill space use impacts are calculated based on the volume of
landfill space consumed by solid, hazardous, and/or radioactive waste. Limestone
production drives landfill space use impacts, contributing 64% of the total impact for
both baseline and lead-free cables. Treatment residue is the top contributing
material flow for both cables, representing 66% of the impact for the baseline cable
and 64% of the impact for the lead-free cable.
Abiotic Ecosystem Impacts
Global warming: The impact scores for the effects of global warming and climate
change are calculated using the mass of a global warming gas released to air,
modified by a global warming potential equivalency factor. Jacketing resin production
drives global warming impacts, contributing 57% and 62% of the total impact for
baseline and lead-free cables, respectively. Carbon dioxide is the top contributing
material flow for both cables, representing 89% of the total impact for each cable.
Stratospheric ozone depletion: Ozone depletion impact scores are based on the
identity and amount of ozone depleting chemicals that are released to air. Electricity
generation drives stratospheric ozone depletion impacts, contributing 77% and 81%
of the total impact for baseline and lead-free cables, respectively. CFC-11 is the top
contributing material flow for both cables, representing 44% of the impact for the
baseline cable and 45% of the impact for the lead-free cable.
Photochemical smog: Photochemical smog refers to the release of chemicals that
may react with sunlight in the atmosphere to produce photochemical oxidants, such
as tropospheric ozone. Jacketing resin production drives photochemical smog
impacts, contributing 91% and 93% of the total impacts for baseline and lead-free
cables, respectively. Unspecified volatile organic compounds (VOCs) are the top
contributing material flow for both cables, representing 77% of the impact for the
baseline cable and 79% of the impact for the lead-free cable.
Acidification: Acidification impacts refer to the release of chemicals that may
contribute to the formation of acid precipitation. Jacketing resin production drives
acidification impacts, contributing 71% and 77% of the total impacts for baseline and
lead-free cables, respectively. Sulfur dioxide is the top contributing material flow for
both cables, representing 58% of the impact for the baseline cable and 56% of the
impact for the lead-free cable.
30
-------
Air particulates: Air particulate impacts are based on the amount of particulate
matter with an average aerodynamic diameter less than 10 micrometers (PM10) that
is released to the air. Jacketing resin production drives air particulate impacts,
contributing 65% and 75% of the total impacts for baseline and lead-free cables,
respectively. Dust is the top contributing material flow for both cables, representing
93% of the impact for the baseline cable and >99% of the impact for the lead-free
cable.
Water eutrophication (nutrient enrichment): Eutrophication (nutrient enrichment)
impacts to water are based on the identity and concentrations of eutrophication
chemicals released to surface water after treatment. Electricity generation drives
water eutrophication impacts, contributing 64% and 57% of the total impacts for
baseline and lead-free cables, respectively. Chemical oxygen demand is the top
contributing material flow for both cables, representing 88% of the impact for the
baseline cable and 86% of the impact for the lead-free cable.
Human Health and Ecotoxicity
Occupational health - potential non-cancer: Occupational impact scores are based
on the potential toxicity of material inputs to each process. This characterization
method does not necessarily indicate where actual exposure is occurring. Instead, it
uses the inputs of potentially toxic materials as surrogates for exposure. Insulation
compounding drives potential non-cancer occupational health impacts, contributing
64% and 54% of the total impacts for baseline and lead-free cables, respectively.
Flame retardant #2 is the top contributing material flow for both cables, representing
58% of the impact for the baseline cable and 54% of the impact for the lead- free
cable.
Occupational health - potential cancer: Jacketing compounding drives potential
cancer occupational health impacts, contributing 85% and 94% of the total impacts
for baseline and lead-free cables, respectively. Phthalate plasticizer #2 is the top
contributing material flow for the baseline cable, representing 81% of the total
impact. Phthalate plasticizer #5 is the top contributing material flow for the lead-free
cable, representing 92% of the total impact. Both phthalate plasticizers are
characterized by default toxicity hazard values.
Public health - potential non-cancer: Impact scores are calculated based on the
identity and amount of toxic chemical outputs with dispositions to air, soil, and water.
Inventory items do not truly represent long-term exposure. Instead, impacts are
-------
relative toxicity weightings of the inventory. Jacketing resin production drives
potential non-cancer public health impacts, contributing 67% and 75% of the total
impacts, respectively, for baseline and lead-free cables. Sulfur dioxide is the top
contributing material flow for both cables, representing 98% of the impact for the
baseline cable and 99% of the impact for the lead-free cable.
Public health - potential cancer: Jacketing resin production drives potential cancer
public health impacts, contributing 64% and 57% of the total impacts, respectively, for
baseline and lead-free cables. Nitrogen oxides (NOx) are the top contributing material
flows for the baseline cable, representing 34% of the total impact. Unspecified
volatile organic compounds (VOCs) are the top contributing material flows for the lead-
free cable, representing 35% of the total impact. Both NOx and unspecified VOCs are
characterized by default toxicity hazard values.
Potential aquatic ecotoxicity: Potential aquatic ecotoxicity impacts refer to the effects
of chemical outputs on non-human living organisms. Plasticizer production drives
potential aquatic ecotoxicity impacts, contributing 51% and 81% of the total impacts,
respectively, for baseline and lead-free cables. Copper +1 and +2 ions are the top
contributing material flow for both cables, representing 46% of the impact for the
baseline cable and 62% of the impact for the lead-free cable.
32
-------
Question 8:
Overall, where are the greatest potential
health and environmental impacts?
CMR
The point estimate results from the CMR impact assessment showed mixed results
for both baseline and lead-free cable types, though the disparities between the cable
impact scores for most impact categories were minimal (Table 5.1). In eight impact
categories, the lead-free cable construction had less environmental burden; however,
six of those categories generated inconclusive results due to the large impact
uncertainty. In other words, overlap of the 10th and 90th percentiles eliminated the
possibility of statistically significant differences. Two categories—potential public
chronic non-cancer toxicity and potential aquatic ecotoxicity—had less environmental
burden for the lead-free cable and did not have overlapping uncertainty ranges. Of
the six categories that showed lower burdens for the baseline cable, only two did not
have overlapping results due to uncertainty: potential occupational cancer and non-
cancer toxicity. The following processes were the top contributors to a majority of the
impact categories for the CMR cables evaluated in this study (see Table 8.1):
• Electricity Generation - Electricity generation was the top contributing
process in the baseline cable life cycle for 6 impact categories: non-
renewable resource use, energy use, global warming, ozone depletion, air
acidification, and eutrophication. For the lead-free cable, the generation of
electricity for cable extrusion was the top contributing process for the same 6
impact categories, in addition to being the top contributor to the potential
public non-cancer toxicity and potential aquatic toxicity impact categories.
• Resin Production and Compounding - For both cables, jacketing resin
production was the top contributing process for the photochemical smog
formation, air particulates, and potential public cancer toxicity impact
categories. The compounding of the jacketing was the top contributing
process to the potential occupational non-cancer and cancer toxicity impact
categories for both cables]
• Landfilling - Municipal solid waste landfilling was the top contributing
process to the potential public non-cancer toxicity and potential aquatic
ecotoxicity impact categories in the baseline case. Lead from landfilling was
-------
the top flow contributing to the potential public non-cancer toxicity and
potential aquatic ecotoxicity impact categories. Landfilling was not a top
contributor to any of the impact categories for the lead-free cable.
These results help to identify potential areas of environmental improvement.
However, it must be noted that the results of this study are in the context of examining
the relative differences of resin systems and their additives. Therefore, focusing
solely on the top contributors identified here does not provide complete life-cycle
impacts from the entire cable (e.g., impacts associated with the copper conductor
were not examined in this study).
The point-estimate results from the cradle-to-gate analyses of the baseline, lead-free,
and zero-halogen CMR cables showed that the zero-halogen cable had far greater
environmental burden in all of the impact categories, except for potential
occupational non-cancer toxicity. These results were not presented with the same
level of detail as the other results, because the available upstream data for the
halogen-free cable only allowed for the modeling of the upstream energy production
and jacketing compounding processes. Since the cable manufacturing (extrusion)
process was not included, this also precluded having data for downstream EOL
processes.
CMP
The point estimates from the CMP cable analyses showed that all impact categories,
except for potential occupational cancer toxicity and landfill space use, had fewer
impacts (i.e., less environmental burden) for the lead-free cable than for the baseline
cables. However, only four of these impact categories— potential occupational non-
cancer toxicity, potential public chronic non-cancer toxicity, potential aquatic
ecotoxicity, and ozone depletion — did not have overlapping 10th and 90th
uncertainty ranges, suggesting greater confidence in these results. The following
processes were the top contributors to a majority of the impact categories evaluated
in this study (see Table 8.1):
• Resin Production - The production of jacketing (PVC) and insulation (FEP)
resins were top contributors to 3 impact categories each. For both baseline
and lead-free cables, the production of the jacketing resin, PVC, was the top
contributing process for the photochemical smog formation, air particulates,
and potential public cancer toxicity impact categories, for which unspecified
VOCs were the top contributing flow. The production of FEP was the top
contributing process to energy use, global warming, and ozone depletion.
-------
• Electricity Generation - The generation of electricity for cable extrusion was
another major contributing process to both cables. In the case of the baseline
cable, electricity generation was the top contributing process for the non-
renewable resources, air acidification, and eutrophication impact categories.
In the case of the lead-free cable, electricity generation was the top
contributor to the same impact categories, as well as to the potential public
non-cancer toxicity and potential aquatic ecotoxicity impact categories.
• Landfilling - For the baseline CMP cable, the top contributing process to the
potential public non-cancer toxicity and potential aquatic ecotoxicity impact
categories was municipal solid waste landfilling. For both of these categories,
the top contributor was lead, which was assumed to leach from the landfill
into groundwater. For both cables, the landfill space use impact category was
also dominated by the municipal solid waste landfilling process.
These results help to identify potential areas of environmental improvement.
However, it must be noted that the results of this study are in the context of examining
the relative differences of resin systems and their additives. Therefore, focusing
solely on the top contributors identified here does not provide complete life-cycle
impacts for the entire cable (e.g., impacts associated with the copper conductor were
not examined in thisstudy).
NM-B
The point estimates from the NM-B cradle-to-gate cable comparisons showed that all
categories, except for potential occupational non-cancer toxicity, had fewer impacts
for the lead-free cables than for the baseline cables. No uncertainty or sensitivity
analyses were run for this comparison because both cable extrusion and the end-of-
life stages were excluded from the analyses due to lack of data, and those stages
were the only ones in which there were large uncertainties.
In the NM-B analysis, which excludes the extrusion process and subsequent
downstream processes, the production of the jacketing resin, PVC, is the top
contributor to eight impact categories. It is followed by electricity generation from
compounding (2 categories), then limestone production (1 category), insulation
compounding (1 category), jacketing compounding (1 category), and phthalate
production (1 category) (see Table 8-1). These results identify processes that could
be the focus of environmental improvement opportunities for upstream and cable
-------
insulation compounding processes. However, it must be noted that these results are
in the context of examining the relative differences of resin systems and their
additives. Focusing solely on the top contributors identified here does not provide
complete life-cycle impacts for the entire cable (e.g., impacts associated with the
copper conductor were not examined in this study).
Table 8.1
Top Contributing Processes: CMR and CMP Full, and NM-B Partial Life Cycle3
Process
Electricity generation
Natural gas production
Jacketing/insulation13
Jacketing additive prod.
MSW landfilling0
Total impact categories
CMR
Baseline Lead-free
6
0
5
0
3
14
8
0
5
0
1
14
CMP
Baseline Lead-free
3
1
7
0
3
14
5
1
7
0
1
14
NM-B
Baseline Lead-free
2
0
10
2 =
N/Ae
14
2
0
10
2o
N/Ae
14
a Number of impact categories for which the specified process is the top contributor
"Includes jacketing and insulation resin production as well as jacketing and insulation compounding
c The two processes for jacketing additive production in the NM-B analysis were limestone production and
phthalate production.
-------
Question 9:
What are the limitations of the study?
LCA Limitations and Data Uncertainties
LCI
Uncertainty in the inventory data depends on how the data are characterized by
submitters, and other limitations identified during inventory data collection. These
uncertainties are carried into the impact assessment. Uncertainties in the inventory
data include, but are not limited to, the following:
• missing individual inventory items;
• missing processes or sets of data;
• estimation uncertainty;
• allocation uncertainty/working with aggregated data; and
• unspeciated chemical data.
In general, the number of primary data sets available for the upstream and
manufacturing processes was quite limited. The greatest number of data sets
collected for a particular process was three (e.g., CMR jacketing compounding).
Where primary data could not be obtained, secondary data were used for some of the
upstream processes. Further investigation into the proportion of the market modeled
in this LCA is necessary in order to understand the potential magnitude of the
uncertainty in the material and energy inputs derived from primary and secondary
data used in this study.
Additionally, the full life cycle was not included in the NM-B analysis due to lack of
available data. Lacking the full life-cycle inventory for the NM-B cable type, it is
difficult to predict how the partial life-cycle impacts would compare to a full life cycle.
The partial life-cycle results can, however, inform decisions about material and energy
use during the cable insulation and jacketing compounding processes.
Sensitivity Analysis
The sensitivity analysis was used to probe the contributions to overall impact
uncertainty from each of the stochastic parameters (see Question 4). Results of the
analysis, shown in Table 9.1, give the largest contributing parameter along with the
percent variance in the impact result attributable to this dominant parameter. It is
evident that one parameter—the energy used for cable extrusion—is responsible for
-------
most of the variation in impacts for each cable type. However, for the CMR and CMP
baseline cables, the uncertainty in the potential public chronic non-cancer toxicity and
the potential aquatic ecotoxicity categories are dominated by the landfill leachate
parameter. For all cables, thermoplastic recycling dominates the landfill space use
indicators. The sensitivity analysis results showed that most categories were not
greatly affected by the EOL assumptions, especially the proportion of cable destroyed
in building fires.
Table 9.1
LCIA Sensitivity Analysis Results
Impact Category
NRR
Energy
Landfill space
Global warming
Ozone depletion
Smog
Acidification
Air participates
Eutrophication
Pot. Occ. rvon-ca
Pot. Occ. cancer
Pol. Public non-ca
Pot. Public cancer
Pot. Aq. ecotox
Parameter that dominates the uncertainty (% contribution)
CMR CMP
Baseline Lead-free Baseline Lead-free
Energy {98}
Energy <>50)c
Recycle (63)
Energy (98)
Energy (98)
Energy (99)
Energy (94)
Energy (98)
Energy (98)
Energy (97)
Energy (98)
Landfill (83)
Energy (86)
Landfill (90)
Energy (98)
Energy (>50)c
Recycle (65)
Energy (97)
Energy (98)
Energy (99)
Energy (92)
Energy (98)
Energy (98)
Energy (96)
Energy (97)
Energy (98)
Energy (96)
Energy (98)
Energy (98)
Energy (>50)c
Recycle (88)
Energy (99)
Energy (98)
Energy (99)
Energy (92)
Energy (98)
Energy (98)
Energy (96)
Energy (97)
Landfill (78)
Energy (90)
Landfill (90)
Energy (97)
Energy (>50)c
Recycle (86)
Energy (98)
Energy (98)
Energy (99)
Energy (92)
Energy (98)
Energy (98)
Energy (95)
Energy (97)
Energy (97)
Energy (96)
Energy (98)
1 Results are reported as the dominant parameter (percentage of the overall impact result variance for which it is responsible).
6 Energy = Variance of extrusion energy; Recycle = Percentage of cabte going to thermoplaslics recycling: Landfill = percentage of
lead lost from landfill: NRR = non-renewable resource use: Pot. = potential: Occ. = occupational: Aq. ecotox = aquatic ecotoxicity.
c Actual percentage withheld to protect confidentiality.
LCIA
Some of the limitations and uncertainties in the LCIA derive from limitations and
uncertainties in the inventory stage; however, many are unique to the LCIA. The
limitations and uncertainties associated with the LCIA include but are not limited to
• Lack of Spatial and Temporal Relationships - The purpose of an LCIA is to
evaluate the relative potential impacts of a product system for various impact
categories. There is no intent to measure the actual impacts or to provide
spatial or temporal relationships linking the inventory to specific impacts. The
LCIA is intended to provide a screening-level evaluation of impacts.
Impact Score Parameter Uncertainty - Uncertainties are inherent in the
parameters used to calculate the various impact scores. For example, toxicity
-------
data require extrapolations from animals to humans and from high to low
doses (for chronic effects), resulting in a high degree of uncertainty. Sources
for each type of data should be consulted for more information on
uncertainties specific to each parameter.
• Chemical Ranking/Scoring System Uncertainty - Uncertainties exist in
chemical ranking and scoring systems, such as the scoring of inherent
properties approach used for human health and ecotoxicity effects. In
particular, systems that do not consider the fate and transport of chemicals in
the environment can contribute to misclassifications of chemicals with
respect to risk.
• Chronic Toxicity Endpoint Uncertainty - Uncertainty is introduced where it was
assumed that all chronic endpoints are equivalent, which is likely not the
case.
• Screening Level Tool for Chemical Risk - The human health and ecotoxicity
impact characterization methods presented in the WCP LCIA are screening
tools that cannot substitute for more detailed risk characterization methods;
however, the methodology is an attempt to consider chemical toxicity at a
screening level for identifying potentially toxic materials in the inventory.
Due to the limitations in the LCI data, no category was given a "high" relative quality
rating (see Tables 5.1, 6.1, and 7.1). In addition to LCI uncertainty, LCIA uncertainty
contributes to the overall limitations. The categories with greater model and data
uncertainty in the LCIA were given "medium" to "low" ratings. For example, the
potential cancer impact category results were mostly based on materials that lack
data on carcinogenicity rather than being based on known carcinogens. Also, as
specific gaps in data contributing to stratospheric ozone depletion were identified,
this category was given a "low" rating. This was due to the lack of information on the
generation and emission of brominated organic byproducts during brominated
phthalate production. Finally, the toxicity-based impact categories use inputs or
outputs as surrogates for exposure and do not model fate and transport and actual
exposure. This could be the subject of further analysis, such as a targeted risk
assessment.
39
-------
Question 10:
What can wire and cable suppliers,
manufacturers, and waste managers do to
reduce environmental impacts?
This section identifies selected opportunities for reducing the overall environmental
and human health impacts of jacketing and insulation of communication cable
products, based on the results of the full life-cycle LCA results (CMR and CMP lead
and lead-free analyses). Opportunities for improvement are broken down into three
categories: upstream material production and use, electricity generation, and end-of-
life disposition.
Upstream Materials
The upstream production and use of certain materials in wire and cable formulations
has a significant effect on many of the overall life-cycle impact category results. The
materials that contribute to cable-associated environmental burden are, in order of
decreasing impact, lead heat stabilizers, jacketing and insulation resins, phthalate
plasticizers, and filler materials (e.g., calcined clay and limestone).
Lead Heat Stabilizers
Lead byproducts that originate in the baseline cable heat-stabilizers are responsible
for much of the potential public non-cancer toxicity and potential aquatic ecotoxicity
burdens for both CMR and CMP baseline cables. This is the most substantive
difference between the baseline and lead-free cables with regards to any of the
impact categories. While there was confidence in the observed difference between
the leaded and lead-free cables, the absolute scores of each are dependent on
parameters that have not been well studied, such as the proportion of lead that
leaches out of landfilled resins and landfill failure rates. Attempting to understand
the potential hazards inherent in the use of lead stabilizers is important for
stakeholders; however, this study cannot provide definitive findings about actual risk
or relative risk between baseline and alternative cables. Because the environmental
impacts resulting from the use of lead heat stabilizers are seen primarily at the
product EOL, they are discussed further in the EOL disposition section below.
40
-------
Jacketing and Insulation Resins
The manufacture of jacketing and insulation resins contributes substantially to a
number of impact categories in both CMR and CMP cables, including energy use and
non-renewable resources, potential public cancer toxicity (NOx and VOC production),
potential occupational non-cancer toxicity (potentially toxic chemicals used in
jacketing/insulation resin production), air acidification, air particulate production, and
photochemical smog production. Increasing the energy-efficiency of resin production,
and reducing or capturing air emissions is likely to reduce the overall environmental
burden. The use of alternative input materials during jacketing and insulation resin
production might reduce overall environmental burden. However, in order to
determine if this is the case, the life cycle analysis would have to be rerun,
substituting the new, less toxic materials.
Phthalates
Phthalate plasticizers were major contributors to the potential occupational cancer
toxicity impacts, especially in the case of CMR cable, where they represented a far
higher fraction of the overall cable mass than in CMP cable. Due to phthalates'
affinity for lipids, exposure in workers could potentially result in bioaccumulation over
time. Though the issue of whether certain phthalates function as carcinogens has
not been entirely resolved, the monitoring of worker cohorts for phthalate body
burden and the minimization of direct contact with this suite of chemicals may be
advantageous.
Elecricity Generation
Electricity generation throughout the wire and cable life cycle, particularly for use in
upstream material production and cable extrusion, played an enormous role in the
overall environmental burden of wire and cable products analyzed here. For the CMR
cables, the generation of electricity for cable extrusion was the top contributing
process in 6 and 8 impact categories for the baseline and lead-free cables,
respectively. For the CMP cables, the generation of electricity for cable extrusion was
the top contributing process in 3 and 5 impact categories for the baseline and lead-
free cables, respectively.
Additionally, the sensitivity analysis (Table 9.1) revealed that the large impact
uncertainty ranges for both the CMR and CMP cables were mostly attributable to the
uncertainty in the energy needed for cable extrusion. This was the case for all
categories except potential public non-cancer toxicity and potential aquatic
ecotoxicity, which were dominated by leachate uncertainty in the baseline cable, and
-------
42
landfill space use, where the percentage of resins recycled after chopping had a
greater effect on the results for both cable types. The range of extrusion energy,
modeled using a uniform uncertainty distribution, was quite large (>50% of the
aggregated value in both directions), so the resulting sensitivity of the model results
to this parameter was not entirely surprising. However, the fact that the uncertainty
associated with the use of energy during cable extrusion is based on actual inter-
company variability is a reminder that the sample size of the primary/secondary
datasets used, and the product or material market share represented by these
datasets, is important in determining the accuracy of the life-cycle modeling effort.
These findings suggest that identifying opportunities for reducing energy inputs would
likely have a large effect on many of the environmental and human health impact
scores for wire and cable products.
EOL Disposition
This study found that the end-of-life stage generates the most sizeable impact
differences between baseline leaded cable and lead-free cable. For both CMR and
CMP, the difference between the two cables was most pronounced in the potential
public chronic non-cancer (CMR: 1,460 versus 279 kg noncancertox-equivalent;
CMP: 952 versus 358 kg noncancertox-equivalent) and potential aquatic ecotoxicity
impacts (CMR: 17.5 versus 0.113 kg aqtox-equivalent; CMP: 8.64 versus 0.151 kg
aqtox-equivalent), with the lead-free cables displaying much lower impacts in these
categories. The sensitivity analysis demonstrated that the lead leachability
assumptions are responsible for the majority of the variability in these impact results.
Therefore, given that the LCIA methodology is a screening-level assessment of
potential toxicity effects, the results of this study indicate that further investigation
into the leachability of lead from cables disposed of in landfills is warranted, as well
as a more targeted evaluation of exposure and risk of lead leachate from the landfill.
Beyond the issue of lead, EOL disposition choices for wire and cable products are
complicated by the trade-offs inherent to the processes themselves. The
sequestration of wire and cable waste by landfilling is not without its source of
potential hazards beyond that of lead. The release of methane from landfilled resins
impacts global warming potential, and the PVC waste could become, over long periods
of time, a source of other halogenated emissions. Incineration, while advantageous
from a landfill space use perspective, results in airborne lead emissions, which can
be problematic from a public health standpoint. Thermoplastic recycling is energy-
intensive and creates new waste streams, which must then be landfilled. The choices
-------
are not straightforward, and depend, among other things, on regulatory standards,
economic incentives, and the value placed on different environmental burdens.
The uncertainty analysis revealed that several impact categories are sensitive to the
variabilities defined here. Further refinement of the inventory data and EOL
assumptions that are the subject of the uncertainty analyses would help reduce
uncertainties and lead to more reliable study results. In addition, LCA results such as
those presented here provide a type of screening analysis where differences across
cables in various impact categories are shown in the context of uncertainty. In some
instances discernable differences cannot be inferred; however, where more
significant differences are likely (e.g., potential public non-cancer and potential
aquatic ecotoxicity) further refinement is warranted, such as using health risk
assessment techniques to begin to identify human and ecological health risks.
43
------- |