Environmental Product Declarations (EPDs) provide a transparent view of a product’s environmental impacts across its life cycle. However, relying solely on Global Warming Potential (GWP) gives a narrow perspective and misses other critical concerns such as water scarcity, acidification, and resource depletion. To achieve a complete and credible sustainability assessment, products must be evaluated across multiple impact indicators.

Relying on a single metric is like diagnosing a patient’s health solely based on body temperature. It may detect fever, but it may miss other health issues like high blood pressure. To address this, frameworks such as EN 15804 mandate the evaluation of core environmental indicators across industries.

Understanding the Differences Between Core Impact Indicators

Each indicator measures a specific environmental issue.

• Global Warming Potential (GWP): Greenhouse gas contribution to climate change. Example: Driving a gasoline car for 100 km emits ~13 kgCO₂e (IEA,2020).
• Acidification Potential (AP): Air and water acidification from emissions. Example: Energy use in the production of one kilogram of cheese releases ~4 molH⁺e (Williams, 2011).
• Eutrophication Potential (EP): Nutrient pollution in water bodies. Example: Using 300 kg of urea releases ~1.17 kgNe emissions (Hasler, 2015).
• Photochemical Ozone Creation Potential (POCP): Smog formation. Example: Using 1 litre of solvent-based paint in construction or automotive can release around 0.2 NMVOCe (US EPA, 2025).
• Ozone Depletion Potential (ODP): Damage to the ozone layer. Example: A Halon fire extinguisher can release ~3 kg CFC_-11e (EPA, 2025).
• Abiotic Depletion Potential (ADP): Use of fossil and mineral resources. Example: A 100 cc gasoline two-wheeler consumes ~0.74 MJ of fossil fuel per km (Aryan, 2022).
• Water Deprivation Potential (WDP): Water consumed in production processes. Example: Producing 1 kg of cotton in a drought-prone area requires ~1 m³ of water (Kumar, 2018).

Industry-Specific Relevance

While GWP is often the most discussed indicator, focusing only on climate change ignores other critical environmental issues. For example, a product with low GWP might still have high WDP, making it unsustainable in water-scarce regions. Similarly, industries like construction, agriculture, and manufacturing need to evaluate their impacts across multiple indicators to make informed sustainability decisions.

The relevance of the core environmental impact indicators in life cycle assessment (LCA) varies across industries, making specific indicators more relevant. Tailored evaluations based on these indicators ensure EPDs relevant for diverse industrial contexts. A research study was performed to understand the significance of impact indicators in relatable, real-world scenarios. Different sectors prioritise specific metrics based on their environmental footprint. Below are industry-specific examples supported by real-world data:

Construction materials

• GWP: Producing 1 kg of cement-based plaster emits ~0.14 kgCO₂e. While the production of 1 kg steel reinforcement bar emits ~2.6 kgCO₂e (International Finance Corporation)
• ADP-Fossil: Manufacturing 1 tonne of hot-rolled steel coil consumes ~20,000 MJ of fossil energy (Backes, 2021).

Transportation

• GWP: Emissions from a flight (150 passengers) between London and Glasgow (560 Km) are approximately 48.5 kgCO₂e (Barnsley, 2023)
• ADP- Fossil: Travelling 1 km in a 100cc electric vehicle will produce approximately 0.44 MJ (Aryan, 2022).

Agriculture & food production

• WDP: Producing 2 kg of coffee beans in drought-prone regions consumes ~1 m³ of water (Kumar, 2018).
• EP: 1 hectare of tomato production emits approximately 12 kgNe (Canaj, 2019).

Manufacturing & industry

• ODP: A Halon-based fire extinguisher emits ~3 kg CFC-11e (EPA, 2025).
• ADP-Elements: Producing 1 kg of copper depletes ~0.14 kgSbe (Oers, 2019).

Waste management & land use

• GWP-Biogenic: Landfilling 1,000 kg of biodegradable waste generates ~900 kgCO₂e (EPA, 2022).
• GWP-LULUC: Clearing 1 acre of forest for urban development emits ~8,000 kgCO₂e.

Standards and Frameworks

Frameworks such as EN 15804 require a broad set of core and additional indicators, ensuring assessments capture climate, resource, and toxicity impacts. Thus, the frameworks ensure that EPDs report:

• Core environmental indicators (e.g., GWP, WDP, AP, EP, POCP, ADP)
• Additional Mandatory Indicators (e.g., Human Toxicity, Land Use)
• Natural Resource Use Indicators (e.g., Energy Use, Water Use, Recycled Content)
• Waste production (e.g., hazardous, non-hazardous, radioactive waste)
• Output Flow Indicators (e.g., materials for reuse, recycling, and energy recovery)
• Biogenic Carbon Content (e.g., Carbon Stored in Materials)

Conclusion

No single metric captures a product’s full environmental impact. By combining multiple indicators, EPDs reveal trade-offs between carbon, water, land, and resource use. This multi-dimensional view strengthens sustainability reporting and helps industries and consumers make more credible decisions.