Whether you’re perusing the latest issue of an architectural magazine or reading a green building blog online, the word “disclosure” is certain to catch your eye. With the release of the latest version of the LEED Green Building Rating System (LEED v4),1 disclosure has taken center stage in the ongoing discussion of how “green building” is defined. And sharing the stage with disclosure are new tools such as Environmental Product Declarations (EPDs) and Health Product Declarations (HPDs), which have emerged to help measure the “greenness” of building products. But in order to understand disclosure’s eventual impact on building design and practice, it is important to start with a review of how the concept developed and how it is related to other important sustainable building concepts.
Many different stakeholders within the building community have been active in the promotion of disclosure, but they all tend to share similar questions. A particular building material may help save operating energy, but how does it impact other equally important environmental concerns? A product may have a high recycled content, but after the effort required to salvage, transport, and convert the material, is there still a tangible net environmental benefit? Beyond specific environmental concerns, how does the product affect the safety, health and well-being of building occupants?
Unfortunately, many of these questions cannot be answered effectively using current tools such as energy calculators and one-dimensional green product certifications. Although disclosure offers an opportunity to move from guesswork to informed decision-making, it is important to recognize that it remains a work in progress, raising perhaps as many questions as answers.
Environmental Product Declarations (EPDs)
EPDs have been around the longest of all the new disclosure tools, and current procedures to develop EPDs have been in place for over a decade. However, the fact that even this disclosure tool is still relatively new attests to how quickly the concept of disclosure has entered the construction market. Nevertheless, the current EPD process has been built on a solid, science-based approach that examines total environmental impact over the entire lifecycle of a product.
There are many excellent definitions of EPDs, but for the purposes of this article, the EPD may best be described as a tool that discloses recognized environmental impacts, using quantifiable measures, over the product lifecycle in accordance with globally recognized procedures.
Recognized Environmental Impacts
The environmental impacts reported by EPDs are based on a universally recognized listing of impact categories established by the U.S. Environmental Protection Agency (EPA). This listing, called the Tool for the Reduction and Assessment of Chemical and other Environmental Impacts (TRACI), categorizes a number of key environmental impacts related to the release of various chemicals into the atmosphere, ground and water. Currently, five of the impacts are included in the data provided by most EPDs. Table 1 provides a listing of these five impact categories, along with a brief description of their effects.
In addition to these primary environmental impact categories, EPDs also include an analysis of the energy consumed during the product’s lifecycle and classify this energy into renewable and non-renewable sources. In addition, EPDs include data regarding water and other resource consumption, as well as information about hazardous and non-hazardous waste generated over the product lifecycle.
All of the data reported in an EPD are also quantified based on the best current science in order to allow for comparison of environmental impacts among similar products. In the case of the five key TRACI impact categories, these measures are based on chemical or molecular values that can be added to the impacts of other products to help establish an overall environmental “footprint” for a combination of products, such as a building or major building component. Table 2 provides a listing of the specific metrics associated with each TRACI impact category.
In all cases, the specific chemical selected may be used as a common denominator for other chemicals that produce a similar result. As an example, although carbon dioxide (CO2) is the most-recognized greenhouse gas, the TRACI tool allows for the conversion of other greenhouse gasses such as methane (CH4) and ozone (O3) into the equivalent amount of CO2 that would cause the same effect. Because the TRACI measures accommodate the range of chemicals associated with environmental impact, these measures can be added to the impacts of other products to establish an overall environmental “footprint” for a whole building constructed from these products.
The assessment and measurement of the environmental impacts reported in an EPD are structured to include all aspects of a product’s lifecycle, from the initial acquisition of raw materials to the eventual removal and disposal of the product. This lifecycle typically is described in an EPD using a diagram similar to Figure 1.
Key elements of the product lifecycle include the identification of all resource inputs (e.g., raw materials, energy, water, etc.) and all environmental outputs (e.g., atmospheric emissions, waterborne waste, solid waste, etc.) associated with the key stages of the product lifecycle, including raw material acquisition, transport, manufacture, installation, maintenance, removal, disposal, etc. The diagram also typically includes a system boundary to indicate exactly what processes are covered within the lifecycle assessment. As an example, the system boundary for many consumer products does not include the operation or use of the product, while almost all building material EPDs include maintenance and operational impacts within the system boundary.
In addition to using quantifiable and well-known measures of environmental impact based on established science, EPDs are conducted in accordance with the requirements of rigorous international standards. In almost all cases, these procedures are based on standards adopted and maintained by the International Standards Organization (ISO). Some of the ISO standards relevant to EPDs include:
• ISO 14044 Environmental Management - Lifecycle Assessment - Requirements and Guidelines
• ISO 14025 Environmental Labels and Declarations - Type III Environmental Declarations - Principles and Procedures
• ISO 21930 Sustainability in Building Construction - Environmental Declaration of Building Products
The use of well-established procedures helps ensure that the information disclosed in an EPD has been developed in an objective and scientific manner. In fact, the type of EPD required by LEED and other green building guidelines requires a final third-party review to validate the disclosure for accuracy and reliability.
EPDs in Codes and Standards
EPDs are included as part of LEED v4 under Option 1 of Credit MRc2 (“Building Product Disclosure and Optimization: Environmental Product Declarations”). In this option, LEED credit may be awarded for projects that incorporate at least 20 products covered by EPDs. Full credit is available for products covered by product-specific declarations, while half-credit is awarded for products covered by a generic industry declaration.
EPDs also may soon become part of other well-known green building codes and standards. Recently, the inclusion of EPDs has been proposed as an addendum to the ASHRAE 189.1 Standard for the Design of High-Performance Green Buildings; the addendum is currently undergoing public comment and review. In addition, several proposals to add EPDs to the International Green Construction Code (IgCC) were submitted as part of the 2014 code hearings process and may be formally approved for inclusion in the 2015 version of the IgCC.
Benefits and Limitations of the EPD
Based on the previous discussion, it should be obvious that the key benefits of EPDs are related to the quantitative, scientific and standardized approach used in their development. This combination of sound measurement, good science and recognized procedure certainly helps to ensure the validity and reliability of the environmental data contained in EPDs.
In addition, because of the quantifiable basis for all measurements, the data for a specific product can be added to the data for other products to obtain a relatively reasonable picture of the overall environmental impact of whole buildings and major sub-assemblies. Finally, the measureable values contained in EPDs can be used not only to compare products but to improve existing products. In fact, one of the original rationales for the development of EPDs was to develop useful tools to drive continuous product improvement.
Of course, the benefits of EPDs come with a cost; one key limitation is the amount of resources required. Based on this researcher’s own experience in helping material manufacturers and trade associations develop EPDs, the entire process is very resource intensive. In addition, the complexity of the development process also may be viewed as a limitation. For starters, the inherent complexity of EPDs, combined with the current lack of overall environmental impact data, means that it is possible for different EPD practitioners to obtain different results using the same basic procedures. More importantly, because construction and design professionals usually aren’t chemists by training, it may be very challenging to select building products simply based on factors such as CO2 equivalents or moles of H+ ions.
Finally, although EPDs offer a way to compare the environmental aspects of building products, they currently fail to address more specific issues involving human health. And because of this limitation, the Health Product Declaration (HPD) has been developed.
Health Product Declarations (HPDs)
Compared to EPDs, the HPD is a brash newcomer, with the first HPD standard formally published just a few years ago. As a result, the most significant difference between EPDs and HPDs involves the degree of rigor and standardization in their underlying processes. Where EPDs rely on scientific method and quantifiable measurement, HPDs rely less on certainty and more on precaution. In fact, one of the founding values of the HPD is the precautionary principle, which advocates for the restriction or elimination of products if there is any concern about their safety.
In addition, the measurements used in HPDs may be considered much less quantifiable than EPD metrics. Rather than providing a measurable effect on health impact, the HPD simply identifies the presence or absence of specific chemicals. As with EPDs, there are many definitions of HPDs; in light of our previous definition of the EPD, the HPD may best be described as a tool that discloses product ingredients and, based on a variety of reference sources, discloses known/suspected health hazards associated with these ingredients.
Without a doubt, the most critical feature of the HPD is the full disclosure of all ingredients in a building product. Because many building materials, especially materials other than liquids such as coatings or adhesives, are not specifically subject to previous material safety data sheet (MSDS) or current safety data sheet (SDS) regulations, manufacturers are under no obligation to disclose the specific ingredients in their products. And even though many building materials manufacturers do in fact voluntarily provide MSDSs and/or SDSs for their products, procedures regarding the disclosure of important health impacts that may be relevant to the building designer are not well-established.
As a result, the HPD may offer a more standardized approach to the disclosure of ingredients. Current HPD standards also allow for the use of proprietary ingredients without disclosing the specific chemical or mixture, as long as the health hazards are clearly identified and disclosed.
After a product’s chemical ingredients have been identified in an HPD, these chemicals must be screened against a variety of reference lists that identify any health hazards known or suspected to be associated with the ingredients. Frequently, these lists are referred to as being “authoritative” because many of the lists have been established by leading national and global bodies based on the best science available. However, these lists may vary significantly in terms of their recognition and scope. Some examples of current HPD “authoritative” lists are shown in Table 3.
It should be noted that Table 3 provides only a partial listing of current HPD reference sources. The full listing in the current HPD Open Standard includes over one dozen compilers and over two dozen specific lists.
For any chemical flagged by one or more of these lists, specific hazard warnings are provided by the list compiler. Similar to hazard warnings on the MSDS, these warnings identify hazards related to specific health concerns, such as cancer, reproductive toxicity, developmental toxicity, etc. Table 4 provides a selected listing of typical hazard language associated with a selection of current HPD reference lists. After screening each chemical ingredient against the hazard references, all known and suspected hazards as identified by these lists must then be reported as part of the HPD.
HPDs in Codes and Standards
HPDs are included as part of LEED v4 under Option 1 of Credit MRc4 (“Building Product Disclosure and Optimization: Material Ingredients”). In this option, LEED credit may be awarded for projects that incorporate at least 20 products covered by HPDs or similar disclosures. Like EPDs, HPDs also may soon become part of other well-known green building codes and standards. As an example, several proposals involving HPDs were included as part of the 2014 code hearings for the 2015 version of International Green Construction Code (IgCC).
Benefits and Limitations of the HPD
Undoubtedly the biggest benefit offered by the HPD is the minimal amount of resources needed to produce it. In contrast to the exhaustive science required to develop an EPD, the time and effort to develop an HPD is much less demanding. Because product manufacturers already possess a reasonable understanding of their ingredients and have access to data from their raw material suppliers, the effort required to produce an HPD differs little from the work needed to produce the common MSDS. Based on the experiences of several manufacturers who participated in a pilot trial of HPDs in 2012, completing the first HPD may take a day or two. After the first HPD is finished, it is likely that additional HPDs can be completed in less than a day.
Along with low resource requirements, HPDs also offer an innate simplicity not available with EPDs. Instead of reviewing dozens of complex measures involved in quantifying a broad range of environmental impacts, the sole function of an HPD is to identify the presence or absence of known or suspected health hazards. As a consequence, HPDs may be more suitable for the non-scientist to review and use. As stated by Russell Perry, FAIA, of architectural firm SmithGroupJJR: “We do not need everyone to be an industrial hygienist in order for (HPDs) to be a valuable contribution to the building industry. We are not scientists in all of this and we don’t need to be. We’re not making risks assessments. We’re simply saying we have to get what these products consist of out into the world.”1
The most obvious limitation of the HPD relates to its infancy as a standard. Unlike widely recognized standard processes such as ASTM, ANSI and ISO, the HPD protocol was developed using an “open standard” approach advanced by a coalition of health-oriented building advocates. This protocol, called the HPD Open Standard, was developed primarily by representatives of the founding sponsors with little or no formal public participation. In addition, material manufacturers did not directly participate in the development of the standard, but rather were relegated to a pilot trial of the standard that was for the most part in its completed form. As a result, many of the guiding principles of standard consensus processes (e.g., open participation, balanced stakeholders, consideration of all viewpoints, and the availability of an appeals process) were not included in the development of the current HPD protocol.
Perhaps as a result of the limited consensus process involved, the current HPD Open Standard includes a number of weaknesses and discrepancies. First, the current HPD standard fails to clarify if it is necessary to report chemical ingredients that are effectively transformed or consumed during manufacture. As an example, the production of polyurethane products such as foam insulations, coatings, and sealants requires the use of MDI, a chemical considered hazardous when directly exposed to humans. But for polyurethane products produced in the confines of a factory, all of the MDI is consumed and transformed into a resultant cellular foam that itself contains no MDI. Even in field applications of polyurethanes, after proper application, no MDI remains when the material is ready for inclusion in a completed building.
The lack of clarification in HPDs also is challenging in regard to chemical mixtures. Many popular roof and wall products rely on the use of materials that may be considered hazardous when airborne in a factory setting, but in almost all cases these materials are firmly encapsulated into a larger chemical matrix that poses little or no risk of release into the building environment. Examples of such materials include titanium dioxide (TiO2), which is a key component in almost all “cool” building products, and carbon black, which is a key ingredient in rubber membranes and sealing gaskets. Some hazard lists, such as California Proposition 65, even include wood dust as a hazard. Does that mean we should identify all wood products to be hazardous?
The lack of clarification regarding ingredients is further compounded by the broad and disparate collection of “authoritative” lists used to identify hazard. Some of these lists, such as the EU REACH protocol, are widely acclaimed and accepted throughout the world. In most cases, this acceptance is due to the high levels of science and consensus used to develop the list. Others, such as California Proposition 65, are more regional in scope and in many cases are simply derivative collections of hazards identified by other lists. Some of the lists, like the U.S. EPA Work Plan List, do not actually identify a known hazard but rather are used to identify materials that are being subjected to further government review. Finally, some of the lists, such as the San Antonio Statement, are not actually lists but rather a public statement of opinion by a group of concerned individuals.
Regardless of the level of recognition each “authoritative” list has achieved, the hazards they identify must be treated as equal threats within the HPD reporting protocol. As a result, many products that contain absolutely no hazardous chemicals as identified by the world’s most recognized authorities still must be identified as hazardous if they contain any ingredient included in the dozens of less-recognized lists and sources covered within the current HPD framework.
Taken as a whole, the potential for product exclusion within the current HPD Open Standard protocol may be significant for many segments of the building material industry. As an example, HPDs for the vast majority of building products will likely include the disclosure of at least one ingredient alleged to be hazardous by one or more of the “authoritative” lists. Table 5 provides a listing of these products, the alleged hazards they may contain, and the reference list from which the alleged hazard is identified.
Table 5, which includes so many critical building materials, may help illustrate one more concern about the current HPD Open Standard. When this researcher has raised examples of products in this table to leading green building advocates, their response has been, “Well, I’m sure the HPD Open Standard doesn’t intend to flag all these products as hazardous. After all, many of these ingredients, like TiO2 or wood dust or carbon black, when fully embedded in building materials will likely never affect building occupants.” This argument may be valid, but how will manufacturers respond in their published HPDs?
As an example, if a building product manufacturer produces a product containing even a theoretical portion of any California Proposition 65-listed ingredient (and there are over 400 of them) and fails to list the ingredient on its product labels and literature, the company could be in legal jeopardy for failing to comply with the specific reporting requirements of Prop 65 in the State of California. And past experience from California suggests that there are plenty of law firms just looking for the opportunity to initiate a Prop 65 lawsuit. As a result, it is unlikely that any product manufacturer will fail to report these ingredients and their alleged hazards in the HPDs they publish.
Likewise, how will building designers respond to HPDs that contain hazard warnings about cool roof coatings, wood, carbon black, and the like? They will be in possession of information stating the products they plan to specify contain ingredients potentially hazardous to the health of the clients. As a result, the inclusion of so many chemicals that may only be remotely connected to actual occupant health hazard could easily damage the credibility of the HPD as an objective and effective tool. In simpler terms, if the HPD flags every building product as hazardous, the relevancy and usefulness of the tool will be lost.
The final and perhaps most critical limitation of the current HPD Open Standard is the lack of risk assessment to accompany the current hazard identification. Stated simply, many materials may be considered potentially hazardous, but a useful understanding of the actual hazard requires an assessment of the risks involved. Some of the key elements of risk assessment currently lacking in the HPD Open Standard include:
• Threshold level—what level of exposure actually produces adverse health effects? Using toxicological science and experimental evidence, a maximum threshold level can be established, usually with a significant margin of safety (MOS) typically in the thousands.
• Exposure path—how can any particular hazardous ingredient directly affect building occupants? In the case of many roof and wall products, especially exterior products or materials such as insulation that are enclosed within walls and roofs, the potential for exposure will likely be very low.
Unfortunately, the current HPD protocol provides little or no information that may help a building owner or designer make decisions based on the actual risk posed by a building product.
Be Proactive, But Cautious
Although this article has identified a number of limitations of EPDs and HPDs, it is important to recognize that everyone associated with green building agrees that increased transparency is a good thing. At a minimum, these environmental and health declarations will provide a better understanding of the building material supply chain and how it may impact our environment and health. Hopefully, this understanding will grow as we continue to refine and improve the reporting standards and protocols. Finally, and perhaps most importantly, increased product disclosure will help drive continuous improvement of the building materials we use.
At the same time, judgments concerning the suitability of any particular building product or comparisons among products will remain difficult and unpredictable. As a consequence, any building designer seeking to apply the information in EPDs and HPDs should always consider the risks involved. These risks include the possibility of overlooking important factors or trade-offs, as well as the risk of arbitrary exclusion of otherwise excellent products and suppliers.
Perhaps the best recommendation going forward is to be proactive in the process—but cautious with the results. Yes, we should all agree that increased disclosure is a good thing and we need to get the process started. But we also should keep in mind that our tools are very new and still unproven in application.
As industry begins to engage in a new level of product disclosure and review, it will be important to avoid oversimplification, especially if it may lead to sweeping changes in product selection. To avoid oversimplifying the challenges we face, it will be important to continually emphasize science, best practices, and continuous improvement as the best tools for assessing and selecting sustainable building products.
1. Weeks, K., “Taking a Stance on Transparency,” ECOBUILDING Pulse, October 2013, www.ecobuildingpulse.com/green-materials/taking-a-stance-on-transparency.aspx.
Editor’s note: This article is based on a paper presented at the Center for Polyurethanes Industry’s 2014 Technical Conference.