EPD Impact Categories in Plain English
EPDs live or die by a handful of impact categories. Understand what each metric actually measures and you can steer product design, marketing claims, and bid sheets with confidence instead of guesswork.
Global warming potential (GWP)
The headline act. GWP adds up every greenhouse gas a product emits, converts them into carbon-dioxide equivalents, and spits out a single figure. Designers latch onto it because cuts here translate directly to climate goals and LEED v5 points (IPCC, 2024).
Ozone depletion potential (ODP)
Think of the 1990s aerosol scare: ODP tracks chemicals that nibble away at the stratospheric ozone layer. Numbers are tiny—often measured in micrograms—but regulators still watch them like hawks (EPA, 2024).
Acidification potential (AP)
Sulfur and nitrogen oxides leave smokestacks, float through the sky, then fall as acid rain on forests and facades, affecting soil and water alike. AP bundles those culprits into one sulfur-dioxide equivalent figure so architects can see corrosion risk up front.
Eutrophication potential (EP)
When nutrients such as phosphates or nitrates wash into rivers they turbo-charge algae, starve fish of oxygen, and turn clear water pea-soup green. This category is split into freshwater, marine, and terrestrial sub-scores under EN 15804+A2 (CEN, 2023).
Human toxicity – cancer (HTP-c)
Some substances lodge in tissue and may trigger tumours years later. HTP-c models fate, exposure, and dose-response to express that cancer risk per kilogram emitted.
Human toxicity – non-cancer (HTP-nc)
Other chemicals strike organs or disrupt hormones without causing cancer. HTP-nc uses the same LCA toolkit to quantify those non-cancer impacts so product stewards can rank hazards quickly.
Photochemical ozone creation potential (POCP)
Hot summer day, traffic jam, hazy skyline—that smog owes plenty to volatile organic compounds (VOCs) reacting in sunlight. POCP expresses the smog risk of a product’s emissions as kilograms of ethene equivalent.
Abiotic depletion potential – minerals & metals (ADP-Minerals&Metals)
Copper, lithium, rare earths: once they’re mined they are gone for good. This indicator tallies how fast we are spending the planet’s non-renewable stockpile and flags hotspots for circular-design fixes.
Abiotic depletion potential – fossil (ADP-Fossil)
Same logic, different resource. It converts every joule of oil, gas, or coal consumed across the life cycle into megajoules of energy content, highlighting energy frugality—or waste.
Water deprivation potential (WDP)
Water scarcity is rising even in temperate regions. EN 15804 now reports net water use separately from mere extraction, a nuance that avoids penalising closed-loop cooling systems (UNEP, 2025).
Particulate matter (PM)
Tiny PM2.5 particles trigger asthma and heart disease. This category pools primary particulates and secondary precursors into disease-case equivalents, giving health and safety teams a hard number to chase.
Ionizing radiation potential (IRP)
Mostly an issue for power-hungry processes drawing from nuclear grids. It quantifies the human health impact of radioactive releases along the fuel chain, expressed in kilobecquerel cobalt-60.
Eco-toxicity – freshwater (ETP-fw)
Here the question is: what does the product leak do to fish, plants, or soil microbes in rivers and lakes? Results are usually presented as comparative toxic units for aquatic species; large numbers ring instant alarm bells.
Soil quality index (SQP)
Heavy metals, compaction, or lost organic matter can cripple soil fertility. SQP sums those pressures into one score so landscape architects and agrifood clients can spot soil-health red flags early.
Land use
Clearing forest for raw-material extraction or plant expansion locks in habitat loss and carbon releases. LCA land-occupation metrics reveal where a product eats up natural or arable land and guide offset or restoration plans.
Why these categories matter commercially
Contractors no longer scan EPDs for carbon alone. Many public tenders now score at least three additional categories, and 37 percent of specifiers in the U.S. said secondary impacts swayed their 2024 purchasing decisions (Dodge Data, 2024). Miss the full picture and you risk being swapped out late in design, when you have no time left to respond.
A quick playbook for manufacturers
- Confirm which categories your product standard (PCR) mandates.
- Check data quality for the top three cost drivers—often energy, binders, or coatings.
- Model improvement scenarios early so you don’t end up chasing marginal gains during EPD review.
Collecting solid site data upfront means fewer review rounds and a quicker route to publication. Nobody wants to recieve last-minute data requests during factory shutdown season.
Bottom line
Impact categories translate complex chemistry into board-ready metrics. Nail them and you not only satisfy compliance but land on more shortlists, more often.
Frequently Asked Questions
Do I have to report every impact category listed in EN 15804?
Usually yes, unless your product’s PCR explicitly allows an omission with documented justification. Skipping a category without permission risks program-operator rejection.
Which single category do specifiers prioritise in 2025?
GWP still commands the most attention, but surveys show water use and particulate matter are gaining fast in drought-prone U.S. states (USGBC, 2025).
Can I compare products if one EPD uses A1–A3 only and another reports A1–C4?
No. Always align system boundaries before comparing numbers; otherwise you are effectively mixing apples and orchards.
About the Author
Walker Ryan is a climate-tech entrepreneur focused on driving industrial decarbonization through better data. As the founder and CEO of Parq, he helps manufacturers generate high-quality, third-party–verified carbon disclosures at scale—accelerating a traditionally slow and expensive process. Before starting Parq, Walker led over $200 million in sustainability-focused investments as VP of Strategy & Growth at ReStream Solutions, following earlier experience in investment banking at Deutsche Bank. He brings a rare mix of capital markets expertise and hands-on sustainability knowledge to tackling the infrastructure of industrial emissions.
