Lesson 4: Impact Categories

Understanding Impact Categories in Life Cycle Assessment


  • Environmental Evaluation: Life Cycle Assessment (LCA) is a powerful tool for assessing the environmental impacts of products and processes. It allows for a comprehensive understanding of these impacts, aiding in sustainable decision-making and responsible resource management.

Key Impact Categories

ILCD Handbook

  • Guidance from ILCD: The International Reference Life Cycle Data System Handbook, developed by the European Commission’s Joint Research Centre (JRC), offers essential guidance for LCA methodology.

Climate Change or Global Warming Potential (GWP)

  • Measuring Global Impact: GWP quantifies the contribution of greenhouse gas emissions to global warming, evaluating gases like carbon dioxide (CO2), methane (CH4), and nitrous oxide (N2O) in terms of their heat-trapping capacity over a specific time period.

Depletion Potential

  • Resource Depletion: Depletion potential assesses the impact of human activities on non-renewable resource depletion, considering consequences related to the extraction and consumption of finite resources such as fossil fuels, minerals, metals, water, land, and forests.


  • Harmful Effects on Ecosystems: Ecotoxicity measures the harmful effects of substances on living organisms and ecosystems. It assesses the toxicity and ecological risks posed by chemicals, pollutants, or contaminants to plants, animals, and microorganisms.


  • Aquatic Ecosystem Health: Eutrophication occurs when excessive nutrients, primarily nitrogen and phosphorus, enter aquatic ecosystems, leading to the rapid growth of algae and aquatic plants, disrupting the balance of these ecosystems.


  • Environmental Acid Deposition: Acidification assesses the potential for acid deposition due to emissions of acidifying substances like sulfur dioxide (SO2) and nitrogen oxides (NOx). These pollutants can react with atmospheric compounds, leading to acid rain or dry deposition.

Human Toxicity

  • Health Impacts: Human toxicity evaluates the potential adverse effects of substances on human health, considering exposure levels and toxicity factors.

Particulate Matter Formation

  • Airborne Particles: Particulate Matter (PM) formation assesses the potential generation of fine solid particles or liquid droplets during the product or process life cycle. These particles can have various environmental and health impacts.

Photochemical Oxidant Formation

  • Sunlight-Triggered Reactions: Photochemical oxidant formation involves the creation of reactive compounds in the atmosphere through chemical reactions triggered by solar radiation. These compounds can contribute to air pollution and smog formation.

Ionizing Radiation

  • High-Energy Emissions: Ionizing radiation refers to emissions of high-energy particles or electromagnetic waves capable of ionizing atoms or molecules. This includes alpha particles, beta particles, gamma rays, and X-rays.

Land Use

  • Resource Allocation: Land use in LCIA pertains to the allocation and transformation of land resources throughout the product or process life cycle. It considers land-related impacts and changes, such as deforestation and habitat disruption.

Key Takeaways

  • Life Cycle Assessment (LCA) evaluates environmental impacts and aids in sustainable decision-making.
  • Impact categories like Global Warming Potential (GWP) and Ecotoxicity assess specific environmental concerns.
  • LCA considers resource depletion, acidification, and human toxicity, providing a holistic view of impacts.
  • Eutrophication, particulate matter formation, and ionizing radiation are crucial impact categories in LCA.
  • Land use analysis helps assess land-related impacts and changes throughout a product’s life cycle.
  • Among the most serious impacts are those with negative effects on humans, air, water, and soil.
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