The Health Product Declaration (HPD) Open Standard Overview: PART EIGHT


The Health Product Declaration (HPD) is the most requested materials transparency document in the AEC industry. The HPD has become an important specification tool for LEED v4.1 projects, WELL, and other ratings systems. An HPD consists of two basic parts: a content inventory and a list of potential health hazards associated with product ingredients. Building product manufacturers sometimes have a difficult time navigating the HPD Open Standard. In this continuing series, we review the HPD Open Standard and how it relates to building product manufacturers.

In part eight of our series, we examine 2.2 HPD Open Standard Format Section 2: Content in Descending Order of Quantity. We will focus primarily on 2.2.1 Material or Product. This section focuses on materials in a product (Material) and the substances of which each material is composed (Substance) in a Nested Materials Inventory or the substances of which the product is composed in a Basic Inventory. There is also a “part inventory”, which is an optional addition to the Nested Materials Inventory, and enables the association of materials with parts of the product as they might appear in a bill of materials. If the terms just discussed don’t ring a bell, please refer to our earlier blogs to learn more. Let’s dive in . . .

2.2.1 Material or Product
This section includes several components including general information, percentages, material HPD URL, inventory thresholds, residuals and impurities, material types, and other components. According to the HPD Open Standard, the Content Inventory can be structured using two methods, the Nested Materials Inventory Method and the Basic Inventory Method. The methods for creating a content inventory are based on how contents are categorized and listed and how reporting thresholds are applied. The content inventory lists contents in the product as well as the thresholds established for their reporting, hazard screening information, and other relevant information.

Nested Materials Inventory Method Versus Basic Inventory Method
In this method, thresholds are established for each material and these thresholds govern which substances must be listed under each material. For this method, the product manufacturer must include every material that is part of the product as delivered. Each material must have its own line-item entry, regardless of the extent of further inventory at the substance level. For the Basic Inventory Method, the contents are reported only at the substance level, regardless of the material structure of the product. A product-level threshold must be used.

Building product manufacturers need to decide which inventory method better suits their needs. The advantages of the Nested Materials Inventory include: Allows supplier data to be updated without changing the entire HPD, you can switch out just the component that changes without requiring recalculation of the entire HPD, for complex products that you assemble, you can build the HPD component by component from supplier data, and Nested Materials Inventories provide the most rigorous reporting and are easier for HPD users to read and understand.

The advantages of using the Basic Inventory Method include: the process is easier for simple products with few ingredients and enables you to avoid reporting small quantities of substances that would be required under material-level thresholds. In both methods, product manufacturers routinely want to protect proprietary product formulations. In addition to withholding the identities of substances, manufacturers can protect proprietary information by entering contents of the product as ranges rather than exact quantities.

Bottomline: Building product manufacturers are encouraged to use the Nested Materials Inventory due to its more rigorous reporting, ease of use, and other critical advantages.

Nested Materials Inventory Percent
This is the Material’s percentage in the final product by weight. The percentage is a characteristic of the product rather than the material; it is assigned when the material is added to the product inventory. A fixed percentage is preferred. However, a percentage range may be provided. An average or typical percentage may be included in the Other Material Notes with an explanation of how the average was derived. Ranges should not exceed 20%. If a range does exceed 20%, the reason for the large range must be described in the Other Material Notes for a product to be identified as “Characterized.”

There are several factors to consider when dealing with percentages. Product manufacturers should be familiar with percentage ranges. If the percentage of the material varies over time due to market availability, pricing or other factors, an explanation must be provided in the Other Material Notes. If the entry is for a substitute material (such as different species of wood used as a veneer), “Alternate” is indicated. As long as the primary material for which it is an alternate has a disclosed percent or percent range, “Alternate” is sufficient for disclosure of percentage for this material. If the percentage is withheld, “Undisclosed” must be entered with an explanation of why this information is withheld in the Other Material Notes. The building product cannot be identified as “Characterized” if the percentage of any material in the product is “Undisclosed.”

Bottomline: Building product manufacturers need to ensure they have the correct percentages for materials and follow the HPD Open Standard to the tee in order to meet the LEED credit requirements. Incorrect data and incomplete sections can invalidate the HPD for LEED contributions, so manufacturers need to be diligent.

Inventory Threshold
“Threshold” is key to understanding the precision of reporting used in the HPD (and ability of the HPD to comply with LEED, Cradle to Cradle, and other programs). The threshold is the amount or concentration of a substance that must be present for that substance to be reported, at the specified threshold level. A lower threshold means that smaller amounts of substances will be reportable and therefore disclosure will be more complete. The HPD Open Standard offers four primary threshold options. They include:

  • 100 ppm: Inventory includes substances at or above 100 ppm (0.01%) concentration in a material or product.
  • 1,000 ppm: Inventory includes substances at or above 1,000 ppm (0.1%) concentration in a material or product.
  • Per GHS SDS: Inventory of substances in a material or product meets the level of resolution required for Safety Data Sheets as prescribed by the Globally Harmonized System of Classification and Labeling of Chemicals: substances that are identified as health hazards are reported at 1,000 ppm (0.1%) for reproductive toxicants, carcinogens, and Category 1 mutagens, and at 10,000 ppm (1%) for all other hazard categories.
  • Other: Inventory of substances in a material or product is based on a completely different protocol, or has more or less stringent thresholds than any of those described above. When selected, an explanation must be provided in either the Inventory and Screening Notes or the Other Material or Other Product Notes.

In a Basic Inventory, a single “Per Product” level threshold must be indicated, which denotes that all substances present in the final product at or above the indicated threshold have been reported. In a Nested Materials Inventory, there are two reporting options: the manufacturer may indicate a threshold for reporting as either “Per Material” or “Per Product”. If inventory data for the substances within a single material or within the product are obtained at multiple threshold levels, the least stringent threshold must be indicated, with further explanation in the Other Material Notes or Product Notes.

Bottomline: The inventory threshold is crucial for contributing to LEED v4.1 MR Credit: Building product disclosure and optimization – material ingredients. Project teams must use at least 20 different permanently installed products from at least five different manufacturers that use any of the following programs to demonstrate the chemical inventory of the product to at least 0.1% (1000 ppm). Building product manufacturers that use outdated SDS that reports ingredients to only 10,000 ppm will not qualify for the credit.

Overall, building product manufacturers need to be careful and meticulous when completing their product HPD. Project teams depend on accurate information for product specification. Manufacturers have a better opportunity of getting their products specified if they have a complete and “LEED compliant” HPD. ▪

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