A

A1–A3
The product stage life-cycle modules: raw material supply, transport to the factory, and manufacturing. Often the only modules included in a 'cradle-to-gate' EPD.
A4–A5
The construction stage modules: transport of the finished product to the building site (A4) and installation (A5).
ADPE / ADPF (Abiotic Depletion Potential)
Two EN 15804 impact indicators measuring the depletion of non-renewable resources: ADPE for mineral and metal elements, ADPF for fossil fuels. Reported as two separate figures, not combined into one score.
Allocation
The method for splitting a shared process's environmental impacts between the multiple products it produces — by mass, economic value, or another physical relationship. ISO 14044 sets a preference order and favors system expansion over allocation wherever that's feasible.
AP (Acidification Potential)
An EN 15804 impact category measuring emissions — sulfur dioxide and nitrogen oxides, chiefly — that increase the acidity of soil and water, expressed in kg SO₂-equivalent.
Avoided burden
Environmental impact credited to a product system for displacing a competing process — recovered energy from waste incineration offsetting grid electricity, for example. The mechanism behind Module D and behind system expansion as an alternative to allocation.

B

B1–B7
The use-stage modules: use, maintenance, repair, replacement, refurbishment, and operational energy and water use.
Biogenic carbon
Carbon absorbed from the atmosphere by biological sources (e.g. trees) and stored in a product, tracked separately from fossil carbon emissions in an EPD's global warming potential results.

C

C1–C4
The end-of-life modules: deconstruction/demolition, transport, waste processing, and disposal.
Comparative assertion
A public claim that one product is environmentally superior to, or equivalent to, a competing product serving the same function. ISO 14044 requires a formal critical review before publishing one — simply comparing two EPDs side by side, without checking they share a PCR, functional unit, and system boundary, doesn't meet that bar.
Complementary PCR (c-PCR)
A product-category-specific rule set that supplements a core PCR like EN 15804 or PCR 2019:14 with narrower requirements — a c-PCR for cement or insulation, for example. Required whenever an EPD reports against a functional unit rather than a declared unit.
Cradle-to-gate
An LCA/EPD system boundary that stops at the factory gate, covering only modules A1–A3.
Cradle-to-grave
An LCA/EPD system boundary covering the full life cycle, from raw material extraction through end-of-life (A1 through C4).
Critical review
An independent check of an LCA's methodology and results against ISO 14044, distinct from EPD verification itself — mandatory whenever a study is used to support a comparative assertion disclosed to the public.
Cut-off criteria
The rule an LCA practitioner uses to decide which minor inputs, energy flows, or waste streams can be excluded from a study rather than fully quantified. The PCR sets the threshold, and whatever's excluded has to be disclosed, not just dropped silently.

D

Declared unit
The reference quantity an EPD's results are expressed against — 1 kg or 1 m³ of product, for example — used when a product's function can't be defined across its full life cycle, typically in cradle-to-gate EPDs. Compare functional unit.

E

Embodied carbon
The greenhouse gas emissions associated with producing, transporting, and installing a material or building, as distinct from its operational emissions.
EP (Eutrophication Potential)
An EN 15804 impact category measuring nutrient loading — nitrogen and phosphorus, chiefly — that can trigger excessive algae growth in water bodies. EN 15804+A2 splits it into freshwater, marine, and terrestrial sub-scores rather than one combined figure.

F

Functional unit
The precisely defined, performance-based quantity an LCA measures impacts against — set by the PCR so results are comparable across manufacturers.

G

GPI (General Programme Instructions)
The rulebook a program operator publishes covering how its EPD program works overall — verification procedures, the process for developing new PCRs, fees, registry rules — as distinct from a PCR, which governs one specific product category.
GWP (Global Warming Potential)
An impact category measuring greenhouse gas emissions in kg CO₂-equivalent. One of several impact categories an EPD reports, not the only one.
GWP-fossil / GWP-biogenic / GWP-luluc
Under EN 15804+A2, global warming potential is reported as three separate sub-indicators rather than one number: emissions from fossil sources (GWP-fossil), the net effect of biogenic carbon uptake and release (GWP-biogenic), and emissions from land-use change (GWP-luluc). The three sum to GWP-total. See GWP.

H

HPD (Health Product Declaration)
A standardized disclosure of a building product's chemical ingredients and any known health hazards, based on the product as delivered rather than its full life cycle. It answers a different question than an EPD — content and hazard, not environmental impact — and the two commonly appear together for the same product.

I

Industry-average EPD
An EPD reporting averaged results across multiple manufacturers or an entire product category, usually published by a trade association. See product-specific EPD.
ISO 14040 / ISO 14044
The two foundational LCA standards: ISO 14040 sets out LCA's principles and framework, ISO 14044 its detailed requirements and methodology. Every EPD's underlying LCA follows these, on top of whichever EPD-specific standard (ISO 14025, EN 15804, ISO 21930) and PCR apply.

L

LCA (Life Cycle Assessment)
The underlying study and calculation methodology that quantifies a product's environmental impacts. An EPD is a standardized document reporting specific LCA results.
LCI (Life Cycle Inventory)
The LCA phase that compiles and quantifies every material and energy input and every emission or waste output across a product's life cycle — the data-collection step that feeds into life cycle impact assessment.
LCIA (Life Cycle Impact Assessment)
The LCA phase that translates a life cycle inventory's raw data into impact-category results (GWP, AP, EP, and the rest) using standardized characterization factors — the step that turns a list of emissions into the numbers an EPD reports.

M

Module D
Benefits and loads beyond a product's own life cycle — recycling or energy-recovery potential — reported separately from A1–C4 since they fall outside the product's own boundary.

O

ODP (Ozone Depletion Potential)
An EN 15804 impact category measuring emissions of substances that deplete the stratospheric ozone layer, expressed in kg CFC-11-equivalent.

P

PCF (Carbon Footprint of a Product)
The total greenhouse gas emissions across a product's life cycle, expressed in kg CO₂-equivalent — effectively an EPD's GWP result reported as a single-issue study on its own, following ISO 14067 rather than a full multi-category LCA.
PCR (Product Category Rule)
The document defining exactly what an LCA must calculate and disclose for a specific product category, written under a core standard like EN 15804 or ISO 21930.
PEF (Product Environmental Footprint)
The European Commission's own LCA-based methodology for measuring a product's environmental impact across 16 categories, using Product Environmental Footprint Category Rules (PEFCRs) in place of PCRs. It overlaps heavily with EPD methodology, and in some sectors a compliant EPD can satisfy PEF requirements without a separate study.
POCP (Photochemical Ozone Creation Potential)
An EN 15804 impact category measuring emissions that contribute to ground-level ozone formation — smog, in effect, as opposed to stratospheric ozone depletion — expressed in kg ethylene-equivalent.
Primary data
Data collected directly from a product's own manufacturing process or supply chain — energy bills, production records, supplier-specific input from the actual facility. Also called foreground data among LCA practitioners.
Product-specific EPD
An EPD reporting one manufacturer's actual data for a specific product or product line, as distinct from an industry-average EPD.
Program operator
The organization that administers an EPD program, oversees verification, and publishes and hosts declarations in a public registry.

R

Representativeness
How well an LCA's underlying data matches the product actually being studied, judged on three axes: temporal (how recent), geographical (right region), and technological (right process). A PCR or program operator's data quality rules set the minimum bar.

S

Secondary data
Data drawn from a third-party life-cycle-inventory database rather than measured directly, used to fill gaps where primary data isn't available — for raw material production or a grid electricity mix, typically. Also called background data.
Sensitivity analysis
Testing how much an LCA's results change when a key assumption or data point is varied, to check whether a result is robust or hinges on one uncertain input. Often reviewed as part of critical review or verification.
System boundary
The set of life-cycle stages and processes included in an LCA's calculation — defined by the PCR, e.g. cradle-to-gate vs. cradle-to-grave.
System expansion
An alternative to allocation for handling a process with multiple outputs: instead of splitting impacts between co-products, the product system is expanded to include the co-product's function, and the impact of whatever it displaces is subtracted out. ISO 14044 prefers this over allocation wherever it's feasible.

T

Third-party verification
Independent review of an EPD's underlying LCA and finished declaration by a verifier not involved in producing it, required before publication under ISO 14025.
Type I environmental label
A voluntary, third-party-certified ecolabel (ISO 14024) awarded to products meeting a program's multi-criteria environmental standard — the EU Ecolabel, for example. Unlike an EPD, it's a pass/fail award against a bar, not a quantified LCA result.
Type II environmental claim
A self-declared environmental claim (ISO 14021) made by a manufacturer about its own product, with no independent verification required — 'contains 30% recycled content' printed on packaging, for instance. Contrast with Type III environmental declaration, which is independently verified.
Type III environmental declaration
The formal ISO 14025 classification for what an EPD is: a quantified, third-party-verified, LCA-based declaration, as distinct from Type I (ecolabels) and Type II (self-declared claims).

U

Upfront carbon
The embodied-carbon emissions released before a building or product is put into use, covering the product and construction stages — A1–A5 — as distinct from whole-life carbon, which also counts everything after that.

V

Validity period
The window an EPD stays valid for after verification — typically five years, though a program operator can set a shorter period, and a significant change to a product's materials or process can force an update before then.
Verifier
The person or panel who conducts an EPD's third-party verification. Program operators distinguish internal verifiers (employed by the EPD owner), external verifiers (independent of the EPD owner but not necessarily accredited), and third-party verifiers (independent of both the EPD owner and whoever performed the LCA).

W

WDP (Water Deprivation Potential)
An EN 15804 impact category — also called the water scarcity footprint — measuring a product's water consumption weighted by how scarce water is in the region where it's consumed, rather than raw liters used.
Whole-life carbon
The total greenhouse gas emissions of a building or product across its entire life, combining embodied carbon (production through end-of-life) and operational carbon (energy used during the use stage). See upfront carbon; compare embodied carbon.