Comments on the PVC Study Methodology of the USGBC's LEED TSAC

Submitted by the Healthy Building Network

January 29, 2004

Introduction

The Healthy Building Network appreciates the opportunity to comment in advance of the stakeholders' meeting scheduled for February 18, 2004 on the TSAC's proposed methodology for evaluating data on PVC and its primary alternatives.

Our comments reflect our perspective that the current inquiry should be conducted within the framework of LEED™. Any PVC-related credit should be developed and evaluated in a manner consistent with other current LEED materials credits. LEED was designed to keep pace with state-of-the-art strategies in materials evaluation and selection. It is well-positioned to refine and enhance its methodologies while maintaining both its systemic integrity and its practical utility to designers. Therefore we first propose amendments to the TSAC methodology to situate a PVC-related credit within the LEED framework and reinforce LEED's leadership role in market transformation.

We also appreciate the TSAC's effort to map and understand the spectrum of environmental and health issues associated with PVC and its alternatives. We are concerned, however, that the TSAC methodology does not adequately incorporate established approaches and methodologies addressing the unique human health impacts associated with inherently dangerous chemicals, such as persistent organic pollutants (POPs) and other persistent, bioaccumulative toxics (PBTs). Nor is the TSAC proposal clear with regard to how it will handle the unavoidable limitations in available data and quantitative analytic tools that render contemporary LCAs a controversial and unsatisfactory metric for multi-attribute materials analysis. Our comments also address these concerns and offer several methods for addressing them.

Specifically we offer these four recommendations with regard to the proposed methodology:

1. Define a PVC-related credit intent.

A clearly defined intent is critical to establishing guideposts for a methodology of analysis. A fundamental goal of a credit evaluation methodology should be to determine whether the credit requirements are capable of achieving the credit's intent. Absent a clearly defined intent, a methodology will lack clear purpose and hence clearly defined research questions. More critically, analysis of a LEED credit without reference to clearly defined intent raises the distinct danger of undermining existing and future materials-related LEED credits by throwing the door open to challenges by any party of interest representing a deselected material.

The intent of PVC-related actions by governments and corporations has been clear: address public health concerns in the life cycle of PVC and/or improve the recyclability of the materials on the market. We suggest that the TSAC clearly define the intent for the credit under discussion before developing the methodology.

The absence of a defined intent may be related to the lack of clarity on the credit in question, which has variously been expressed as: a) a proposed "PVC-elimination" credit in LEED for Commercial Interiors; b) a "PVC-related" credit; and c) a "credit for avoidance of PVC products." Whether the Task Group is assessing a specific PVC "avoidance" or "elimination" credit, or a more broadly construed "PVC-related" credit, and whether this is a distinction with a difference to the Council, requires clarification.

2. Address POPs appropriately in the life cycle of PVC and its alternatives.

Persistent organic pollutants (POPs) are now subject to elimination under international treaty -- the Stockholm Convention on POPs. The Stockholm Convention declares POPs to require action by all nations due to their high toxicity, resistance to degradation, and tendency to move long distances and accumulate in the food chain. Since the Council considered the proposed "PVC-elimination" credit in 2000, 150 nations have recognized the inherent and global human health and environmental dangers of POPs and signed the Stockholm Convention. The Stockholm Convention bears directly on the question before the TSAC as the life cycle of PVC unavoidably contributes to the formation of four of the 12 targeted POPs (dioxins, furans, PCBs, and hexachlorobenzene). Concurrently with the drafting and signing of the Convention, an international consensus has been building on the unique and significant hazards associated with POPs and their relationship to building materials. LEED credits currently are silent on this key international environmental accord -- a situation which must be addressed for LEED to fulfill its mission of industry leadership to emphasize state of the art strategies.

3. Incorporate alternative methodologies for evaluating the relevance of a PVC-related credit.

A diverse set of methodologies are available and in use, primarily in corporations, for evaluating the environmental and health relevance of materials in general and a PVC-related credit in particular. We suggest that the TSAC would benefit by gaining familiarity with these approaches which have directly addressed the intent of reducing POPs and other chemicals of high toxicity concern, as well increasing material recyclability. Significantly, this has been achieved through science-based design-oriented methodologies that emphasize screening out the most toxic materials while transitioning toward increasingly benign substitutes. DesignTex, Herman Miller, Nike, and Shaw Carpet have all used design-based methodologies to evaluate materials and select greener ones. They begin from a set of goals (similar to the intent part of a LEED credit), then evaluate the environmental and health performance of the materials used in their products.

4. Address the hazards in the proposed LCA-like methodology.

The methodology proposed by TSAC is structured quite similarly to a quantitative life cycle assessment (LCA)-type analysis. LEED, however, must not be handicapped by the unavoidable limitations in available data and quantitative analytic tools that render contemporary LCAs a controversial and unsatisfactory metric for multi-attribute materials analysis. We believe the Task Group shares this perspective, as evidenced by their careful statements in Pittsburgh that the methodology under consideration here is not to be construed as an LCA. In this spirit we highlight some of the major hazards that arise in attempts to assess impact through the quantitative LCA-type methodology proposed by the TSAC, including: the discounting of human health impacts and POPs, addressing key but poorly quantified or missing flow data, and the failure to address end-of-life recyclability concerns. Below we address each of these issues in further detail.

1) The need to define intent

1A) Define intent before defining methodology

LEED credits typically start with a definition of the intent of the proposed credit. The intent of the credit defines the primary data points to be considered in justifying a credit and verifying whether the requirements are appropriate to the goals. For example, the intent to support the local economy and reduce environmental impacts from transportation justifies a credit for locally manufactured virgin materials. The intent to reduce the impacts from the extraction of raw materials justifies a credit for high-recycled content. The intent to reduce ozone depletion justifies a credit to avoid CFCs. The integrity of the LEED system rests upon aligning credits with intent as a means of identifying the benefits and detriments of building materials and the credits that encourage or discourage their use. Hence a clear definition of the intent of a proposed LEED credit is essential to a relevant and robust analysis of the credit proposal.

The TSAC solicitation to stakeholders states a goal of analyzing evidence with regard to a "PVC-related" credit, but it is silent with regard to the underlying intent. This is akin to analyzing the evidence regarding a credit related to locally manufactured goods without first clarifying whether the intent is to reduce impacts from transportation or from the extraction of raw materials. Viewed from another perspective, it is difficult to conceive of a functional LEED rating system if the Steering Committee is asked henceforth to rule upon "wood-related," "paint-related," "insulation-related" credits and the like, absent any stated intent of what said credit is attempting to achieve. Intent sets the boundaries for defining the criteria that are most relevant for evaluating the basis for a credit. Therefore, a clear intent must first be defined against which to test the proposed credit requirements before a methodology can be developed to accomplish that test. That is the essence of LEED, and what makes it functional as well as successful.

While LCA tools are increasingly finding usefulness in narrowly targeted manufacturer specific analyses, emergent LCA models remain too complex and controversial to be reliably applied by practitioners to whole industry sector practices. LEED, on the other hand, recognizes that present day materials choices -- even if one could reliably measure the cross category impacts -- would inevitably present unavoidable tradeoffs that must be made in order to signal long term market development. Material-related credits are presently based upon a specific intent without evaluation of other countervailing environmental concerns.

LEED credits are sometimes even in apparent contradiction to each other. Recycled content materials are rewarded even though their climate impact may be excessive because they may need to be transported a much longer distance than locally manufactured virgin materials.  Conversely LEED also rewards the use of virgin materials when the finished product is manufactured within a 500 mile radius of the building, even when a recycled content alternative is available. This may be appropriate due to the need to incur higher long distance transportation costs for recycled products and conversely to encourage consumption of virgin products for a period until the regional market is stimulated sufficiently to encourage investment in local recycling facilities that meet both needs.

LEED designers are provided with the flexibility to seek the credits most appropriate to their situation, selecting the material attributes that best match their environmental and health goals with their other performance criteria and other constraints. Over time, the market will develop to fulfill a broader combination of LEED rewarded attributes simultaneously as LEED catalyzes market transformation (such as decentralizing recycling operations to allow capture of both the local and recycled content credits described above). At this stage of market development and LCA data quality, however, it is likely that few LEED credits could establish an unambiguous overall environmental benefit through the type of quantified multi-category impact analysis proposed here.

Focusing the research question by clarifying the intent of this proposed credit is therefore the necessary first step for the TSAC to meaningfully evaluate the extent to which the available evidence supports a PVC-related credit. We recommend that the intent for the proposed PVC-related credit first be clearly defined. Then the TSAC can propose a methodology that is designed to evaluate how the requirements address the intent. We suggest in the sections below ways to define intent and alternative methodologies for evaluating requirements to meet that intent.

The current methodology proposed by the TSAC represents a dramatic departure from LEED. It proposes a quantitative LCA-type methodology without having a clearly defined statement of intent. To the best of our knowledge, this application of an LCA-type methodology that collects data on twelve or more impact categories would be the first time such an evaluation was applied to a LEED credit. This would herald an ominous shift in LEED credit development. We are concerned that it is laden with pitfalls and distractions (discussed in Section 4) that will lead the analysis away from the needed focus on measuring the success of the credit at meeting its intent. Further, this approach could result in a gridlock for LEED as manufacturers of deselected materials press for evaluations of multiple impact categories beyond the scope of intent of the credit.

1B) The intent of existing PVC-related policies

A review of the PVC-related materials policies from governments and corporations reveals that the intent of these policies is primarily to:

a) protect public health by reducing the use of toxic chemicals and the generation of toxic byproducts, including POPs and other persistent bioaccumulative toxicants (PBTs), throughout the life cycle of the materials and/or

b) increase the end-of-life recyclability of products.

These policy guideposts should provide the framework for defining the intent of the proposed PVC credit.

On the public health side, many organizations have developed policies and begun to implement programs to reduce the use of products and building materials containing PVC. Governmental bodies that have established PVC-related policies include local, state, national and international agencies, such as the Cities of Seattle, San Francisco, Oakland, and Berkeley; the Counties of Marin, Santa Clara, and Alameda; the states of New Hampshire and New York; the countries of Denmark and Germany and the World Bank. These policies are almost entirely based upon efforts to reduce anthropogenic sources of dioxins and other highly toxic materials and/or increase the recyclability of materials by reducing the use of PVC. A few examples are listed here:

• San Francisco passed a resolution in 1999 to "reduce PVC use and eventually become PVC-free where appropriate alternative products composed of non-chlorinated materials are available" based upon health concerns due to dioxin and other toxics in the PVC life cycle. The City subsequently passed an ordinance mandating that City departments avoid PVC use.^[1]

• The City of Seattle committed in 2002 to developing an implementation plan to reduce PBTs that includes among its priority list of products "PVC building materials and office supplies." ^[2]

• New York State passed an act in 2000 to establish a green building tax credit program. The act required the Department of Environmental Conservation (DEC) to promulgate, in consultation with the New York State Energy Research and Development Authority (NYSERDA), regulations that specify materials that qualify for the credit. The DEC excluded PVC from the list of flooring materials that qualify for the credit. Attorney General Eliot Spitzer explained the rationale for the decision in his Respondents' Memorandum of Law to the Supreme Court of the State of New York "In the Matter of the Application of Resilient Floor Covering Institute, and Tarkett, Inc., against New York State Department of Environmental Conservation:"

"Petitioners initiated this litigation to force DEC to list vinyl flooring as a ‘listed material' [i.e., qualifies for the tax credit] under the regulation's flooring section….DEC and NYSERDA, however, determined that vinyl flooring should not be included as a ‘listed material' in the regulations since the burning of polyvinyl chloride (‘PVC') products can result in the production of dioxin, furans, hydrochloric acid (‘HCl'), and other contaminants, and because alternative flooring materials (such as linoleum, cork, and bamboo) were available and more environmentally-friendly than PVC. In addition to being derived from rapidly renewable resources or recycled products, these alternatives were biodegradable and recyclable. Also, the alternatives did not raise certain of the public health concerns associated with polyvinyl chloride (e.g., the production of vinyl flooring and its precursors involved many hazardous materials, including ethylene dichloride, dioxin, vinyl chloride -- which are known carcinogens)."^[3]

• Corporations are also targeting PVC because of toxicity concerns. Nike, for example, is phasing out PVC because:

"PVC has recently come into increasing disrepute as studies have shown the following: the vinyl chloride monomer (used to make the PVC polymer) is a carcinogen; PVC incineration can result in dioxin emissions and dioxins are persistent highly toxic, bio-accumulative substances; phthalates, a group of compounds used to soften PVC have been identified as endocrine disruptors; additives used in PVC contain toxic heavy metals such as lead and cadmium that do not remain bound in the final product; and PVC is not easily recyclable once it has become waste. Based on the scientific literature and an extensive investigative process, Nike decided to phase out PVC from its products."^[4]

• The difficulty of recycling PVC, especially closed-loop recycling, has led the automobile industry to target PVC for elimination. The auto industry is similar to the building industry in that their products have long life cycles. Driven by end-of-life vehicle directives in Europe and Japan to increase the recycling of automobiles, automakers are evaluating their use of plastics and selecting plastics that can be recycled back into the same product. The European automaker, Opel, for example, classified plastics according to their recyclability (see Table 1 below). PVC was next to last on the list, only more recyclable than a mixture of incompatible products.

Table 1. Opel Priority List for Plastics with regard to Recycling Aspects
	__	Polypropylene, Polyethylene
	__	Polyoxymethylene (POM), Polyamide, Thermoplastic Urethane (TPU)
	__	Acrylonitrile Butadiene Styrene (ABS), Polymethylmethacrylate, Styrene Maleic Anhydride (SMA) copolymer, Acrylonitrile Styrene Acrylate (ASA), Styrene Acrylonitrile (SAN)
	__	Polycarbonate, Polyethylene Terephthalate (PET), Polybutylene Terephthalate (PBT)
	__	Thermoplastic Elastomer (TPE)
	__	Polyurethane
	__	Sheet Molding Compound (SMC)
	__	Elastomer
	__	Polyvinyl Chloride (PVC)
	__	Mixture of incompatible materials

Source: Opel, Environmental Report 2000/2001.

• The Green Building Council of Australia established its Green Star building rating system in 2003 with credits for minimization of PVC usage because "Australia does not have any safe method of recycling or disposal" of PVC.^[5] In support of its decision the Council cited the NY Attorney General's discussion of toxic impacts.^[6]

• The World Bank's International Finance Corporation (IFC) concluded in 2003 that "disposal of PVC is associated with the unintentional release of POPs, primarily through the incineration of mixed waste streams containing PVC products." And declared that "to mitigate this risk the IFC will only invest in the manufacture of PVC products that have compelling benefits over alternative products." The IFC cited the Stockholm Convention (see below for more on Stockholm) as the driving force for its policy, noting that "while the Convention's parties are national governments, IFC recognizes that the private sector is critical to its implementation."^[7]

The "intent" of these organizations and institutions in establishing PVC reduction programs is clear: address public health concerns in the life cycle of PVC and/or improve the recyclability of the materials on the market. Given this intent, and their evaluation of the data and alternatives, each has concluded that PVC materials should be avoided.

We submit that the reasons these organizations decided to address PVC should be incorporated into the intent of the PVC credit.

2) The need to address POPs in the life cycle of PVC and its alternatives

While the life cycles of PVC and its alternatives raise a whole range of issues, we suggest that the pre-eminent issue for TSAC to address is the generation and use of toxic chemicals of concern, particularly persistent organic pollutants (POPs) and other persistent bioaccumulative toxicants (PBTs).^[8]

The inherent risks of POPs and PBTs are now universally recognized. Their persistent and bioaccumulative nature means that small releases of these toxic chemicals concentrate as they move up the food chain, migrate widely, and become global concerns regardless of source. Many of these chemicals are known to be particularly detrimental to the developing fetus and very young children. Many have been documented (in animal studies) to have detrimental and sometimes irreversible effects at the lowest measurable levels, which means there is no known safe level. These characteristics distinguish the PBTs from some other chemicals addressed by LEED, such as CO2, for which there is only the need to keep anthropogenic levels under certain limits. Whereas any release of POPs and PBTs is inherently dangerous, the danger with CO2 is not inherent - it plays a useful role in atmospheric chemistry and only becomes hazardous when emissions exceed the earth's assimilative capacity. Thus an environmentally sound goal for CO2 is to limit releases to the capacity of the environment, but the goal for PBTs must be no releases. PBTs are more akin to CFCs, which LEED has recognized as dangerous at any level and made elimination prerequisite.

Because of their extraordinary inherent and global danger, POPs and PBTs are subject to multiple public policy directives at the state and national levels, and, most notably, by international treaty - the Stockholm Convention on Persistent Organic Pollutants. In the Stockholm POPs treaty, parties acknowledged that each country has a responsibility to the rest of the world to act because POPs not only are highly toxic but also "resist degradation, bioaccumulate and are transported, through air, water and migratory species, across international boundaries and deposited far from their place of release, where they accumulate in terrestrial and aquatic ecosystems."[9] Over 150 countries including the US have signed the Convention, agreeing to:

* Protect human health and the environment from persistent organic pollutants based on the precautionary principle in the face of uncertainty about the nature and extent of toxic chemical threats.

* Prevent further production and use of new POPs chemicals.

* Seek to prevent the formation and release of dioxins and other "by-product" POPs.

* Promote - and where appropriate require -- the use of substitute or modified materials to prevent the formation and release of these POPs products and processes, rather than rely on pollution scrubbers and filters to control releases.

The Bush Administration signed the treaty for the United States in May 2001, committing "to reduce the total releases [of dioxins and furans] with the goal of their continuing minimization and, where feasible, ultimate elimination." By comparison, the Kyoto Treaty calls for the reduction, not elimination of greenhouse gases.

At a minimum, LEED needs to be harmonized with the Stockholm Treaty on POPs. The methodology must acknowledge the distinction between persistent and bioaccumulative chemicals, for which elimination is key, and other impact categories that address concerns related to assimilative capacity. The scientific community has agreed that POPs and PBTs are chemicals of global concern and must be treated distinctly from other impacts. We believe this is accomplished most consistently within the LEED framework by defining an intent of the proposed credit that reflects that goal. More completely, we suggest that an important intent of the PVC credit is to:

Reduce the formation of targeted highly hazardous chemicals of concern, with a particular emphasis on dioxin and furans targeted by the Stockholm POPs treaty and on certain other PBTs which have a large presence in contemporary building materials, e.g. lead, cadmium, and mercury (all of which have direct links to PVC production).

The primary focus of the methodology should be on evaluating whether the data sufficiently support the intent of the credit: i.e., that avoiding PVC reduces the formation and release of POPs and PBTs.

3) The need to consider alternative methodologies for evaluating the relevance of a PVC-related credit

Alternative methodologies are available for addressing the areas of intent highlighted above. The international construction firm Skanska, for example, divides products into four categories: 1) restricted, 2) to be phased out, 3) approved but under surveillance, and 4) approved. Another example is the methodology developed by McDonough Braungart Design Chemistry (MBDC) and summarized in the recent article by McDonough, et al., in Environmental Science and Technology. ^[10] MBDC has developed a methodology - they call it a "protocol" - that assesses materials for their environmental sustainability.

The MBDC protocol begins by evaluating the toxicity of materials based upon two categories of criteria: human health criteria and ecological health criteria (see Table 2 for details).^[11] Chemicals are screened through these criteria -- called the "preliminary chemical assessment step" -- to evaluate which are safer than others (see Figure 1). Following this screening process of inputs is an evaluation of the end-of-life performance of the material. Preferred materials are those that can be either safely returned to nature ("biological nutrients") or recycled back into the same product ("technical nutrients"), in addition to being less toxic (as determined by the preliminary chemical assessment step).

Emphasized in this design-based methodology is the importance of designing toxics out of the product (prevent their use and formation) rather than allowing them to be designed into the product, and then having to control them after formation at the end-of-the-pipe. As McDonough, et al., write: "By designing safe, healthful materials that can flow in closed-loop systems, designers and engineers are eliminating waste by putting filters in their heads instead of on the ends of pipes."

DesignTex, Herman Miller, Nike, and Shaw Carpet have used either the same or similar methodologies to evaluate materials and select greener ones. They are all using design-based methodologies, which begin from a set of goals (similar to the intent part of a LEED credit), and then evaluate the environmental and health performance of the materials used in their products. Herman Miller's Design for Environment team, for example, has adapted and expanded upon the MBDC's work, incorporating end-of-life concerns with toxicity concerns (see Table 3).

Notable for the TSAC process is that these rigorous toxicity and end-of-life analyses of chemicals and materials have led Nike and Shaw Carpet to screen out large numbers of materials, PVC among them, in favor of less toxic and more easily recycled materials.

The MBDC "preliminary chemical assessment step" (see Figure 1) provides a method for how to distinguish between restricted and other products. They developed criteria for separating chemicals into four categories: green (little or no concern), yellow (low to moderate concern), red (high concern), and orange (lack data for evaluation).

Figure 1. Preliminary Chemical Assessment Steps from MBDC's Material Assessment Protocol

Source: McDonough, et al., 2003, "Applying the Principles of Green Engineering to
Cradle-to-Cradle Design," Environmental Science and Technology

These are not necessarily the criteria relevant for the TSAC process, but they are examples of possible criteria. The TSAC would need to develop its own criteria, based on the intent of the credit, for separating materials into categories of highest concern. This evaluation of toxicity could be linked with an evaluation of end-of-life concerns, as Herman Miller has done (see Table 3).

Design-based methodologies, which begin from intent then proceed to analysis, are consistent with LEED. LEED's prime mode has been driving toward long term market transformation through optional credits. Having few compulsory credits, LEED allows the practitioner practical latitude in selecting environmental and health goals to emphasize in the project, with the option of minimizing or entirely ignoring some goals in the pursuit of other valid environmental and health goals and paths to market transformation. Thus it will remain true that LEED-certified buildings will be allowed to contain components made with PVC, and resulting in PBT and POPs releases, even after LEED aligns with the international POPs consensus through a PVC related credit.

4) The need to address hazards in the proposed methodology

The preceding analysis highlights the need for the TSAC to establish a methodology that is in harmony with the LEED approach to material market transformation, beginning with a clearly stated intent that is consistent with well-established international treaties, government policies and corporate actions. By so defining and focusing its task, the Task Group will avoid the many difficult obstacles discussed below that arise in developing and using the LCA-type impact matrix methodology as currently proposed.These complications and their implications for other existing and future LEED credits threaten the integrity of the entire LEED system.

The proposed quantified impact analysis methodology raises many questions, including:

• How will the TSAC evaluate the data it collects?

• How will the TSAC address human health impacts?

• How will the TSAC account for poorly quantified, uncertain, and missing data?

• How will the TSAC account for end-of-life concerns?

4A) How will the TSAC evaluate the data?

The proposed methodology does not address how impact categories will be compared and whether they will be aggregated. For each application under review, will all the impact category units be aggregated into a single unit -- for example, as done with BEES 3.0 (Building for Environmental and Economic Sustainability)? If yes, how will the impact category units be aggregated? Will the impact categories be weighted or considered equal? If the impact categories are weighted, how will they be weighted? When evaluating impacts as a whole, LCAs typically aggregate impact categories into a common number. The algorithms for translating diverse metrics, from acid rain to ozone layer depletion to carcinogenicity, are not transparent and filled with many unspecified assumptions.

If impact categories are not aggregated, then by what means will a material be defined as environmentally preferable for that application? How will differing performance in different impact categories be considered in identifying the superior material?

How will the TSAC evaluate materials across applications? As the evaluation methodology stands, it appears that PVC-related credits will be tested by application rather than by material. Is this interpretation correct? If not, and the credits will be done by material rather than by application, how will materials be evaluated across applications?

4B) How will the TSAC address human health impacts?

The methodology does not describe how the data will be transformed into common metrics for the impact categories "human health carcinogens" and "human health other." For example, how will chemical carcinogenicity be translated into "life years"? And how is the carcinogenicity potential of different chemicals assigned? For example, dioxins, furans, ethylene dichloride, and vinyl chloride monomer are all carcinogens produced in the PVC life cycle. How will "life years" be attached to each of these chemicals in each of the stages? Does the TSAC propose a methodology to establish with confidence exactly how many cancers will be caused per functional unit (such as one square foot of PVC flooring) produced? And will the impact category only include Toxic Release Inventory (TRI) reported releases to the environment (a pollution control-oriented approach) or will it include the use of carcinogens as well as carcinogens generated as byproduct (a pollution prevention-oriented approach)? Note that the EPA is concerned enough about whether it is actually capturing the intended chemical releases from the PVC resin industry that it recently began targeting resin manufacturers for "media shifting" of VCM -- avoiding regulation by moving emissions from one medium, such as air, to another, such as wastewater[12].

The Stockholm POPs treaty is very direct about this issue calling upon all signatories to end not only the direct releases of POPs to the environment, but also the storage of these chemicals. Moving dioxin-laden wastes into hazardous waste storage repositories does not constitute compliance with Stockholm.

No metric is specified for the impact category, "human health other." How will a measurable unit be defined? How will the various adverse effects of this category be aggregated into a single common unit? Embedded in this catch-all category are many serious human health effects, including: neurological, reproductive, developmental, and endocrine system effects. Each of these human health effects requires an impact category of its own. Why is carcinogenicity any more relevant to human health than damage to our reproductive or endocrine system?

As the methodology stands, all impact categories will be treated as equal -- no weighting scheme is specified among impact categories -- and the impact categories will not be aggregated into a common number. The problem here is all impact categories should not be treated as equal. Given the intent of other organizations and governments to address public health concerns related to PVC, public health impacts should be weighted significantly more than other impacts.

Completely absent from the methodology is a process for evaluating the presence of persistent or bioaccumulative toxics in the life cycle of a product. Although persistence and bioaccumulative capacity are not impacts, they are indicators of the capacity to cause significant harm to humans and animals. PBTs need to be added as a separate "impact" category reflecting their priority for elimination by both the US federal government and the Stockholm Convention.

The difficulty of assigning a common metric to the "human health other" impact category highlights the tendency of the current method to discount human health concerns. We remain skeptical that the proposed methodology can be transformed to address persistence, bioaccumulative capacity, and all the chronic human health effects in a manner that is of similar quality with many of the other impact categories -- such as climate change and acid rain -- where the data are of higher quality and easier to convert into common units of analysis. The methods for translating releases of chemicals that impact human health into common units are more complex, contain more assumptions, and are subject to greater disagreement. The greater complexity of data and higher uncertainty of data quality will translate into efforts to simplify. Complex impacts such as endocrine disruption and neurological effects will be eliminated to save time and simplify the process. Persistence and bioaccumulation will be discarded because they are not "impact categories." Each of these steps to simplify the process will discount human health concerns that are central to the intent of PVC avoidance policies.

4C) How will the TSAC account for poorly quantified, uncertain and missing data?

For the human health-related categories that are critical to the intent of a PVC credit, many critical pieces of flow data never make it into life cycle analyses because they are uncertain, incomplete, poorly quantified, or just not in the interest of the analyst. For example, a recent analysis of the BEES 3.0 treatment of PVC flooring revealed that there are no dioxin flows from PVC manufacturing included in the model, despite the fact that the US EPA dioxin analysis has quantified certain dioxin flows from the manufacture of VCM and EDC[13].

Furthermore, the EDC/VCM manufacturing dioxin flows enumerated in the oft cited EPA "Inventory of Sources of Dioxin in the United States" are only a small portion of the dioxin flows the EPA and others know to exist. The EPA Inventory is often misunderstood and misused. It represents only estimates of the dioxin flows that have been characterized and quantified to a fairly high degree of reliability, not a complete inventory of total measured flows as it is typically characterized by the PVC industry. A tremendous volume of dioxin flows are known to exist, but their absolute values have not yet been quantified reliably enough to be included in the EPA Inventory chart. For example, the EPA estimates that landfill fires alone (with PVC the primary chlorine donor and therefore a major dioxin factor) may contribute 1000g TEQ of dioxin per year - several orders of magnitude higher than the current EDC/VCM manufacturing estimates.[14] Furthermore, the peer review of the EPA's inventory indicates that the manufacturing numbers may be much less reliable than their placement in the Inventory table indicates.[15]

It is important that the TSAC not fall victim to the common pitfall of LCA-type analyses of assuming a lack of impact or a lack of grounds for action due to failures to include data or uncertainties in the data. Because POPs and PBTs are characterized by their inherent danger to human health, i.e. the lack of a "safe" exposure level or assimilative capacity, failure to incorporate data cannot be presumed to suggest lack of impact. Scientific evidence that demonstrates the potential for high risk from these chemicals and their likely release in the life cycle of materials mandates action without waiting improvement in the absolute quantification of those risks. As we have seen repeatedly in the realm of environmental health hazards -- ozone depletion, climate change, tobacco, lead -- strong positive policy action is often warranted well in advance of the emergence of scientific measurements with the high confidence levels that quantified models like LCAs require. This is one of a multiple set of factors that drive the use of the screening methodologies for chemicals of concern discussed in Section 3, rather than basing judgments on relative weightings of incompletely quantified flows.

4D) How will the TSAC account for end-of-life concerns?

It is widely acknowledged that greener materials can either be recycled or composted at the end of their useful life. Yet the proposed impact category assessment methodology does not evaluate either the recyclability or biodegradability of PVC and its alternatives. While "recyclability" and "biodegradability" are not impact categories, they are indicators of impacts. These factors of green materials need to be incorporated into the methodology.

4E) Summing up the hazard

The challenges highlighted above that are raised by the TSAC's proposed effort to evaluate this credit by quantifying impact flows reflect similar concerns raised by Environmental Building News in the March 2002 issue discussion of LCA tools:

"While LCA is simple in concept, researchers performing LCA studies or developing LCA-based tools for general use face challenges involving nearly aspect of their work. Problems arise concerning the quality, consistency, and availability of data on products and processes; the methods used to compile inventories; and especially the assumptions and systems used to translate inputs and outputs into measures of environmental impact."

"The Holy Grail of the green building movement would be a database in which the life-cycle environmental impacts of different materials were fully quantified and the impacts weighted so that a designer could easily see which material was better from an environmental standpoint. Though efforts are afoot along these lines (see "BEES" in EBN Vol. 8, No. 11 and Vol. 9, No. 9), we are not even close to realizing that goal. Very often, we are comparing apples to oranges. We are trying to weigh, for example, the resource-extraction impacts of one product with the manufacturing impacts of another, and the indoor-air-quality impacts of a third."

TSAC runs the grave danger in this exercise of expending a heroic amount of energy comparing apples to oranges. The answer to the PVC question, we submit, can be arrived in a much simpler, reliable, scientifically defensible manner.

5) Conclusion

We submit that these questions demonstrate how the proposed TSAC materials evaluation process will soon confront major obstacles that are avoided by the current LEED system. The current system accounts well for the inherent contradictions and limitations of a nascent green building movement, an immature market for green building products, and multiple environmental and public health imperatives which overlap, intersect, and occasionally collide.

There is inherent value in scholarly work and pilot projects to study and refine LCA tools, and we look forward to engaging with the USGBC in this important effort to advance the state of a broader multi-attribute analysis of materials in the LEED system. These approaches, however, currently do not offer practical models for everyday materials evaluation. Therefore we recommend the following actions:

1) Clearly define the intent of the credit first. Since the intent of the credit has not been specified it is premature to propose a methodology until that step is completed. We recommend that the intent of the PVC credit is to eliminate the use and release of POPs and PBTs in the material's life cycle.

2) After intent is clearly defined, then the TSAC should develop its methodology for evaluating the merit of a PVC-related credit relative to meeting that intent. We suggest that the methodology should be defined to answer this question:

Is there evidence to support the assertion that avoiding the use of building products and materials containing PVC reduces the use and formation of targeted highly hazardous chemicals of concern, with a particular emphasis on dioxin and furans targeted by the POPs treaty and on certain other PBTs which have a large presence in contemporary building materials, e.g. lead, cadmium, and mercury (all of which have direct links to PVC production).

As the TSAC methodology suggests, this should include the full life cycle of PVC and the major alternatives on the market, but focusing on the chemical impacts, with particular weight to the POPs and PBTs. If there are materials among the alternatives that prove to be equal or worse than PVC in use and generation of the targeted chemicals of concern, they may need to be targeted for exclusion as well.

It is critical that this evaluation include all the relevant data on the use and generation as byproduct of POPs and PBTs throughout the life cycle of the materials considered. Too frequently LCAs exclude this information because the releases are either small (although of great concern) or not in their data set.

3) As TSAC defines a methodology based on intent we recommend that the TSAC seriously evaluate the design-based methodologies developed and used by organizations like MBDC, DesignTex, Skanska, and Herman Miller for evaluating the environmental and health performance of materials. Because these methodologies develop screens to capture the more toxic materials they avoid the need to quantify impacts (which are subject to high uncertainty) and compare across different impact categories. We suggest that the design-based methodologies are more compatible than LCA-type methodologies to the LEED system and more relevant to the intent of a PVC-related credit.

Finally we want to caution that the use of an LCA-type methodology for evaluating the relevance of a PVC credit sets a dangerous precedent for the LEED system. This overall environmental impact evaluation is an approach the USGBC has never applied to any other material credit. By moving down this path the USGBC may set a precedent with significant unintended consequences, including undermining its capacity to be a leader in defining green building materials. The USGBC has created with LEED a system for integrating environmental and health goals into materials selection, providing a catalyst for transforming markets, and providing the design community with needed flexibility in setting project priorities. It is critical that any methodology developed for evaluating a PVC-related credit maintain this system.