HPD Glossary: Key Terms in the HPD Open Standard v3.0

on by Leave a comment

Quick answer

A Health Product Declaration (HPD) is a standardized report of what a building product contains and the health hazards linked to those contents. It is written to the HPD Open Standard, which the Health Product Declaration Collaborative (HPDC) maintains; the current version is 3.0. The terms that come up most often are:

  • GreenScreen score: a hazard rating for each substance. BM scores come from a full GreenScreen assessment, and LT scores come from the faster List Translator screen.
  • LT-1: List Translator “Likely Benchmark-1”. The substance is very likely a chemical of high concern.
  • Residuals and impurities: substances that were not added on purpose, such as leftover monomers or catalysts. An HPD must consider them at the same threshold as the ingredients that were added on purpose.
  • Nested materials: an inventory method that lists each material in the product and nests its substances underneath it.
  • Threshold: the concentration a substance has to reach before it must be reported. The usual levels are 100 ppm (0.01%) and 1,000 ppm (0.1%).
  • Characterized, Screened, Identified: three yes/no flags. They say whether every substance above the threshold has an amount and role, has been checked for hazards, and has a name and CAS RN.

An HPD reports hazard. It does not report exposure or risk, and it is not a certification or label.

What is a Health Product Declaration?

The HPD Open Standard is a voluntary technical specification. It sets how manufacturers report a product’s contents and the health information linked to them. Everything is reported for the product as delivered to the job site. Architects, specifiers, owners and certification programs read HPDs to compare products on material health.

The standard does not do any of the following:

  • certify, label or rank products
  • judge whether one product is “better” than another
  • assess performance
  • replace a life-cycle assessment or an Environmental Product Declaration (EPD)

The Manufacturer Guide to the HPD Open Standard v3.0 is clear that the standard reports hazard only. Exposure and risk need a separate assessment.

HPDs serve as documentation for LEED (the v4/v4.1 Material Ingredients credit), the WELL Building Standard, the Living Building Challenge, Enterprise Green Communities and Cradle to Cradle Certified. They also exchange data with Declare (through Toxnot), Pharos and GreenScreen. The guide counts more than 10,000 published HPDs from over 700 manufacturers.

Every HPD follows the same six sections:

  1. Summary
  2. Content in Descending Order of Quantity
  3. Certifications and Compliance
  4. Accessories
  5. General Notes
  6. References

The glossary below uses the definitions in the HPD Open Standard v3.0 and the HPDC’s Emerging Best Practices documents.

Content inventory terms

Content inventory

The content inventory is the list of everything in the product, together with the reporting threshold and the hazard screening results. Section 1 of an HPD summarizes it, and Section 2 gives the detail.

Material

A material is a uniform (homogeneous) solid, liquid or gas made up of one or more substances. A coating or finish always counts as its own material. A supplied input that doesn’t stay distinct in the finished product, such as a solution dye in a fabric, does not get its own entry.

Substance

A substance is matter defined by the molecules or atoms it’s made of and by physical properties such as density or melting point. Each substance is reported with a name, an identifier (usually a CAS RN), a percent, a role and its hazard results.

Content

“Content” is the standard’s umbrella word for materials and substances together.

Threshold (inventory threshold)

The threshold is the concentration at which a substance must be reported. The lower the threshold, the fuller the disclosure.

Threshold Percent equivalent What it means
100 ppm 0.01% The most stringent common level. LEED v4 Material Ingredients Option 2 requires it.
1,000 ppm 0.1% The common baseline, and enough for LEED Option 1.
Per GHS SDS 0.1% for carcinogens, reproductive toxicants and Category 1 mutagens; 1% for other hazards Covers only the hazardous contents a Safety Data Sheet must list. It does not meet LEED requirements.

A threshold can apply to the whole product (product-level) or to each material separately (material-level).

Nested Materials Inventory

This method lists every material in the product, with the substances above the threshold nested under each one. A substance that appears in two materials is listed twice. The method has two variants:

  • Nested, with material-level thresholds. Each material has its own threshold, which makes this the most rigorous option.
  • Nested, with a product-level threshold (new in v3.0). One threshold applies across the whole product. A material can appear with no substances under it if every one of its substances falls below that threshold.

Nested inventories show which material carries a hazard. They also let you swap in updated supplier data without rebuilding the whole HPD.

Basic Inventory

This method gives one flat list of substances for the whole product, with no materials, against a product-level threshold. It suits simple products with few ingredients. The method can’t be changed after work starts in the HPD Builder without redoing some of it.

Percent (%) and ranges

Amounts are reported as percent by weight. To protect a formula, a manufacturer can report a range of up to 20 percentage points. A wider range needs an explanation in the Substance or Material Notes.

Role

The role is the function a substance or material performs, such as binder, filler, pigment or plasticizer. HPDC standardized the field in v2.2 and keeps a controlled vocabulary of roles.

Material Type

Material Type is a broad class for each material based on its chemistry, such as metal, ceramic, polymeric material or paper. It’s defined in HPDC’s Material and Substance Characterization Best Practice.

Accessories

Accessories are products required for installation, maintenance, cleaning or operation, such as adhesives or fasteners. They’re listed in Section 4. If none are needed, the HPD says “No accessories are required for this product.”

Residuals, impurities and reporting descriptors

Intentionally added substances

These are the ingredients a manufacturer or supplier puts into a product or material on purpose to give it a function. They are what appears in a formulation.

Residuals and impurities (R/I)

Residuals and impurities are substances present in a product or material that were not added on purpose. Examples are unreacted monomers, leftover catalysts or solvents, and contaminants in raw materials. They usually come from the process chemistry. The HPDC’s Best Practices for Considering Residuals and Impurities (June 2025) sets these rules:

  • R/I are considered at the same threshold as intentionally added substances, in both level and scope.
  • R/I below the declared inventory threshold don’t need to be reported.
  • R/I must be reported when they score BM-1, LT-1, LT-P1 or NoGS.
  • The notes have to say what the consideration was based on: direct testing, a supplier SDS, a supplier disclosure letter, other named documentation, or process chemistry via Pharos. An SDS-based note must add that an SDS may not identify every R/I.
  • If none were found, the note says no R/I are expected at or above the content inventory threshold.

Residuals and Impurities Considered

This Section 1 field records whether R/I were evaluated. For a Nested inventory it shows how many materials were evaluated out of the total, written as “X of Y”. For a Basic inventory it is a yes or no. Either way, an explanation is required in the Residuals and Impurities Notes. Some v2.3 and later HPDs label the field “Residuals and Impurities Evaluation Completed”.

Characterized

A product is “Characterized” when every substance above the threshold has its percent weight and its role reported.

Screened

A product is “Screened” when every substance above the threshold has been checked against the HPD Priority Hazard Lists and GreenScreen, with the results reported.

Identified

A product is “Identified” when every substance above the threshold is reported by name and identifier, usually the CAS RN.

A substance can be Characterized and Screened but not Identified. This is how manufacturers protect trade secrets while still showing hazards, and LEED v4 accepts it.

CAS RN

The Chemical Abstracts Service Registry Number is the unique identifier for a chemical substance. An incorrect CAS RN produces incorrect hazard screening, so the most specific applicable number must be used.

Undisclosed / proprietary

A substance is undisclosed or proprietary when its name and CAS RN are withheld. It still has to be characterized and screened. HPDC’s Content Inventory Completeness best practice allows a narrow exception for supplier content that is truly unknown, but only when an HPD Approved Preparer or Third-Party Verifier is involved. That content is capped at 1% of product weight, or 5% when it sits inside a single homogeneous material in a Nested inventory.

Hazard screening and GreenScreen terms

Hazard screening

Hazard screening checks each reported substance against authoritative hazard lists. Those lists are compiled by government agencies and other expert bodies, including the U.S. EPA and the EU. A screening hit means the substance is linked to a hazard. It says nothing about exposure to that hazard, or the risk from it, in the installed product.

HPD Priority Hazard Lists

These are the hazard lists the HPD Open Standard requires substances to be screened against. They are mostly drawn from GreenScreen for Safer Chemicals and also include lists from government agencies. Hits appear as hazard warnings in Section 2.

Pharos Chemical and Materials Library

Pharos is a hazard database run by the Healthy Building Network. The HPD Builder uses it to screen substances automatically, and Pharos also provides the process-chemistry data used to look for residuals and impurities. Some HPDs list the Toxnot Chemical Hazard Screening Library as their screening source instead.

GreenScreen for Safer Chemicals

GreenScreen is an open method for comparative chemical hazard assessment, published by the nonprofit Clean Production Action. An HPD can report two kinds of GreenScreen result:

  • Benchmark (BM) scores come from a full GreenScreen assessment by a licensed profiler. The assessment is a toxicological review of studies, hazard lists, models and analogs. Only a full assessment can rate a chemical as lower concern.
  • List Translator (LT) scores come from the GreenScreen List Translator. It maps a chemical’s presence on GreenScreen Specified Lists against the Benchmark-1 criteria, and no extra toxicological review is done.

GreenScreen score reference

Score Full name What it means
BM-4 Benchmark-4 Prefer: a safer chemical.
BM-3 Benchmark-3 Use, though there is still room to improve.
BM-2 Benchmark-2 Use, but search for safer substitutes.
BM-1 Benchmark-1 Avoid: a chemical of high concern.
BM-U Benchmark Unspecified There isn’t enough data to assign a benchmark.
LT-1 List Translator Likely Benchmark-1 The chemical is on lists that meet Benchmark-1 criteria, so it would most likely score BM-1 in a full assessment.
LT-P1 List Translator Possible Benchmark-1 The chemical is on lists that overlap Benchmark-1 criteria, or on lower-confidence lists. More research is needed.
LT-UNK List Translator Benchmark Unknown The chemical is on a GreenScreen list, but the listing doesn’t map clearly to LT-1 or LT-P1.
NoGS No GreenScreen information The chemical is on no GreenScreen Specified List, and no public full assessment exists.

LT-UNK and NoGS do not mean a substance is safe. They only mean no priority hazard listing was found. A full GreenScreen assessment is the only way to show a substance is affirmatively safer.

Number of GreenScreen BM-4/BM-3 contents

This Section 1 indicator counts the substances that have lower-hazard Benchmark scores from publicly available full assessments.

Contents’ highest-concern GreenScreen score(s)

This Section 1 indicator lists any BM-1, LT-1 or LT-P1 scores found in the product. LEED v4 Material Ingredients Option 2 needs a 100 ppm inventory with no BM-1 or LT-1 substances.

Hazard type codes

In Section 1 and Section 2, short codes after a GreenScreen score show which hazard categories were flagged. Common examples are CAN (cancer), REP (reproductive), DEV (developmental), END (endocrine), MAM (mammalian toxicity), RES (respiratory), SKI (skin), EYE (eye), AQU (aquatic toxicity), PHY (physical hazard) and MUL (multiple hazards).

Form-Specific Hazard

This note, marked with an asterisk, appears on substances such as titanium dioxide or carbon black. It says the substance’s score and hazards are tied to a specific form, usually particulate inhalation. That exposure is expected only during activities like sawing, sanding or grinding.

Additional Listings

Additional Listings are non-hazard lists shown next to the hazard results. They were added in HPD v2.3. Examples include the Living Building Challenge Red List, the Cradle to Cradle Certified Restricted Substances List and REACH exemptions. HPDC’s Technical Committee chooses which lists are included, as described in the Best Practices for Additional Listings.

Special conditions, disclosure and publishing terms

Special Conditions

Special Conditions are HPDC policies for materials that are hard to report substance by substance. Many of them have no single CAS RN or a variable makeup. Each policy sets a structured way to describe the material, often in place of normal hazard screening, which then reads “Hazard Screening is not applicable to this Special Condition”. The HPD notes which ones were used, for example “Special Conditions applied: [BiologicalMaterial]”. The current policies cover:

  • Biological materials, such as wood and other tree-based materials
  • Geological materials, such as stone and minerals
  • Mixed recycled content
  • Polymers
  • Metal alloys
  • Electronics, such as printed circuit boards
  • Fasteners

Yes ex/SC

This Section 1 result means a completeness flag such as Characterized or Screened is “Yes” except for contents reported under a Special Condition. It does not disqualify an HPD from LEED v4 Material Ingredients Option 1.

Metal Alloy Special Condition

An alloy is reported as one ingredient, usually identified by its UNS number, because an alloy’s hazards differ from those of its alloying elements. HPD v3.0 replaces the old free-text notes with a structured, nested inventory of alloy elements, which brings the reporting into line with LEED v5.

Recycled content (RC)

Each substance carries a recycled content code:

  • PreC: pre-consumer, also called post-industrial
  • PostC: post-consumer
  • Both
  • Unk: unknown
  • None

Nanomaterial

This is a yes/no flag for whether a substance is made of nanoscale particles or uses nanotechnology.

VOC content

VOC content is reported in Section 3. It is required for all liquid and wet-applied products.

Supplier HPD

A Supplier HPD is an HPD a supplier fills in for its own material. It feeds directly into the manufacturer’s Product HPD. Suppliers can pass along hazard screening results without revealing proprietary identities. It was introduced with v2.2 and v2.3.

HPD Builder

The HPD Builder is HPDC’s web tool for creating, checking and publishing HPDs. It runs automated hazard screening, completeness checks and the optional LEED Pre-Check, and it exchanges data with tools such as Toxnot through its API. Manufacturers get access through an HPDC membership or by buying token bundles.

LEED Pre-Check Indicator

The LEED Pre-Check is an optional automated check of whether the HPD’s fields are consistent with LEED v4/v4.1 Material Ingredients Options 1 and 2. It reviews items such as the threshold and the Characterized, Screened and Identified flags. It does not judge data quality and is not verification.

HPD Public Repository

The Public Repository is HPDC’s free, authoritative archive of published HPDs. An HPD counts as “published” only once it appears there in the orange-and-blue format. A draft carries a gray “DRAFT Unpublished HPD” watermark. Libraries such as Mindful Materials pull HPDs from the Repository by API.

Third-Party Verification (TPV)

Third-party verification is HPDC’s optional program, consistent with ISO 17065. An approved verifier runs a desk audit that checks the inventory against the supporting documents and confirms undisclosed substances were properly screened. No lab testing is involved. Verified HPDs show a verification mark, and LEED v4.1 gives them extra credit.

Third-Party Preparer

A third-party preparer is an HPDC-approved consultant who builds HPDs for manufacturers. Preparers often work under NDAs to get confidential supplier data.

Emerging Best Practices

Emerging Best Practices are HPDC’s controlled guidance documents, covering residuals and impurities, special conditions, additional listings and similar topics. They supplement the standard and can be updated between versions.

HPD v3.0 terms

  • PFAS Attestation Tool: lets manufacturers declare PFAS presence even below the reporting threshold.
  • PFAS Screening Tool: flags PFAS by cross-referencing CAS numbers against authoritative lists.
  • EU HPD Output: a version for European markets aligned with REACH. It highlights SVHCs and EU hazard classifications.
  • Expanded Product Type Taxonomy: a more detailed product classification harmonized with external datasets such as Athena.
  • Social Equity Certifications and Survey: optional reporting of JUST, B Corp and Fair Trade certifications, plus a voluntary survey on labor and community practices.
  • Digitized, modular format: HPDs become structured digital records instead of static PDFs, with API links to design and certification tools.

Frequently asked questions

What does LT-1 mean on an HPD?

LT-1 stands for “List Translator Likely Benchmark-1”. The substance appears on authoritative hazard lists that meet GreenScreen’s Benchmark-1 criteria, so it would most likely be classed as a chemical of high concern in a full assessment. It’s the most serious score the List Translator can give.

What is the difference between LT-1 and BM-1?

BM-1 is the result of a full GreenScreen assessment by a licensed toxicologist. LT-1 is a faster, list-based screen that predicts BM-1. Both flag a chemical of high concern, and both disqualify a product from LEED v4 Material Ingredients Option 2.

Does LT-UNK or NoGS mean a chemical is safe?

No. Both scores mean only that no priority hazard listing was found. Showing that a substance is safer, at BM-3 or BM-4, requires a full GreenScreen assessment.

What are residuals and impurities in an HPD?

They are substances present that were not added on purpose, such as leftover monomers, catalysts or contaminants. Manufacturers must consider them at the same threshold as intentional ingredients. Any that score BM-1, LT-1, LT-P1 or NoGS must be reported.

What is the difference between Nested and Basic inventory?

A Nested Materials Inventory lists each material and the substances inside it, using either per-material thresholds or one product-level threshold. A Basic Inventory is a single list of substances for the whole product, using a product-level threshold.

Which threshold do I need for LEED?

LEED v4 Material Ingredients Option 1 (disclosure) accepts 1,000 ppm. Option 2 (optimization) requires 100 ppm and no BM-1 or LT-1 contents. Thresholds taken from an SDS do not meet LEED requirements.

Can an HPD keep ingredients confidential?

Yes. A substance can be Characterized (amount and role) and Screened (hazards) without being Identified (name and CAS RN). LEED accepts this.

Is an HPD a certification?

No. An HPD is a standardized disclosure report. It does not rate, certify or compare products, and it does not assess exposure or risk.

Sources

Leave a Reply