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Life Cycle Analysis and Green Building: Credibility at The Crossroads


By Tom Lent
Healthy Building Network
September 16, 2004


The Sustainable Products Purchasing Coalition (SPPC) [1] hopes to catalyze
the market for sustainable products by getting consistent environmental
performance data from manufacturers. They've chosen to do this through an
Eco-Profile - a standardized form through which manufacturers can provide
Life Cycle data for their product compatible with the variety of accepted
Life Cycle Analysis (LCA) tools currently in use in the industry.

Comparable impact information is the holy grail of LCA development and the
SPPC has launched one of the most credible efforts to make it usable for
designers and purchasers. Just how hard this is going to be, however, was
evident last week at a conference entitled "Crossroads, The Intersection
of Green Building and Life Cycle Assessment," co-sponsored by SPPC and the
Cascadia Chapter of the U.S. Green Building Council. [2]

Quantitative LCA tools have become an effective means for industrial
design analysis. The application of these tools to material selection by
the architectural community, however, presents significant challenges that
have not yet been overcome. Current LCA tools can give the user a false
sense of security that the tool is providing a comprehensive, unbiased and
final analysis of all of the environmental impacts resulting from
production, use and disposal of a material, ending the need to ask further
critical questions. In reality, serious data and analysis limitations
inherent in current tools can lead users to strong but hidden biases for
materials with major environmental health impacts that are inadequately
quantified. Without proper acknowledgement of these constraints, LCAs can
turn environmental values upside down.

Take current manufacturer claims that BEES, a U.S. government-sponsored
LCA, proves that PVC-based vinyl flooring (VCT) has less environmental
impact than natural linoleum. [3] This may be a bit surprising to those
familiar with analyses that find PVC to be the worst plastic for the
environment. [4] That's because the European industry model used by BEES
to calculate the manufacturing impact of PVC conveniently left out the
carcinogenic dioxin emissions, thus tilting the analysis in favor of PVC.
[5] This is a particularly serious omission as dioxin is the most potent
synthetic carcinogen measured by science and subject of international
treaty efforts (signed by the U.S.) to stop its production [6]. As a
result, good intentions to do the right thing for the environment are
thwarted, and twenty years worth of environmental policy making on dioxin
is undermined every time a green building professional relies upon this
information to select vinyl over linoleum.

The inherent complexity and limitations of LCA have led some experts and
numerous manufacturers to devise alternative decision making tools which
employ chemical screens -- blacklists if you will -- that align design
standards with agreed upon environmental health policy goals, such as the
elimination of dioxin and other chemicals of concern. [7] Presently,
chemical screening systems offer the practitioner the most useful and
credible guidance on the environmental health impact of material selection
and are critically necessary in the face of LCA's blind spots and pitfalls.



 

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