Life Cycle Assessment (LCA): how to evaluate a product's environmental impact

Companies can no longer simply claim to be green: regulators and customers demand quantitative evidence. The Life Cycle Assessment (LCA) provides that data, because it measures the environmental impacts associated with a product throughout its entire life, from raw material extraction to end of life.

What is a Life Cycle Assessment (LCA)?

The Life Cycle Assessment (LCA) is a standardised scientific methodology that systematically evaluates the environmental impacts associated with all the life stages of a product, process, or service, from raw material extraction (the "cradle") to final disposal (the "grave"). It is used to identify, quantify, and reduce the negative effects of an activity on the environment.

Why is the LCA important?

The LCA offers a holistic, objective view of environmental impact and avoids a common mistake: shifting the problem from one life cycle stage to another, or from one impact category to another (for example, reducing emissions at the cost of increasing water consumption). Thanks to that global perspective, organisations can make informed decisions to optimise resources, reduce costs, and improve the sustainability of their products.

Phases of the LCA: how is it structured?

The LCA is divided into four phases, according to the ISO 14040 (principles and framework) and ISO 14044 (requirements) standards:

Phase 1: goal and scope definition

The functional unit is identified (a 500 ml glass bottle, one kilometre travelled, etc.) and the system boundaries are set. The choice between cradle to gate and cradle to grave conditions the whole study and must be justified.

Phase 2: life cycle inventory (LCI)

The inputs and outputs of each process are recorded (energy, water, materials, emissions, waste). Primary data come from meters or internal systems; secondary data from databases such as Ecoinvent or Agribalyse. You can go deeper in the article on the Life Cycle Inventory.

Phase 3: impact assessment (LCIA)

Using methods such as Environmental Footprint 3.1 or ReCiPe 2016, the inventory is translated into indicators of climate change, eutrophication, toxicity, or water footprint. If you are interested in the latter, see the article on the grey water footprint.

Phase 4: interpretation and improvement

The LCA reveals the critical points (hot spots), the stages where most of the impact is concentrated. Acting on them, for example by switching to renewable electricity in an energy-intensive process, directly reduces the product's environmental burden.

Key indicators in environmental impact assessment

The LCA uses different indicators to measure impact across the life cycle:

• Greenhouse gas (GHG) emissions: carbon dioxide (CO2), methane (CH4), nitrous oxide (N2O), among others.
• Energy consumption: energy used in extraction, manufacturing, transport, and end of life.
• Water consumption: water used in production processes.
• Waste generation: solid and liquid waste and emissions to the atmosphere.
• Resource depletion: use of non-renewable raw materials.

What applications does the LCA have?

• Eco-design: optimises materials and processes to reduce impact from the design phase.
• Public policy and regulation: serves as a basis for standards and eco-labels.
• Environmental Product Declarations (EPDs): make it possible to communicate environmental performance transparently and comparably.
• Comparisons between products: help choose the most sustainable option among alternatives, provided they fulfil the same function.

Advantages and limitations of the LCA

Advantages

• Offers a comprehensive, data-based assessment.
• Supports strategic sustainability decision-making.
• Improves credibility and transparency with customers and regulators.

Limitations

• Requires specialised software and extensive databases.
• Can be costly and complex, especially for SMEs.
• Interpreting the results requires technical expertise.

How to start measuring environmental impact

For a first approximation you can use Manglai's carbon footprint calculator and quickly estimate emissions and other indicators. For a rigorous, comparable study, the recommended approach is a full LCA supported by a platform such as Manglai's product footprint, which structures the data and connects it with reporting. You can also consult the guide to methods and tools for the LCA.

Frequently asked questions about the LCA

Is an LCA mandatory to declare a carbon footprint?

No, but ISO 14067 requires you to justify the study boundaries; a simplified LCA is usually the most robust solution.

Is the LCA mandatory for all companies?

It is not mandatory in every sector, but more and more regulations and customers require it as a guarantee of sustainability.

Can I compare different products with an LCA?

Yes, provided they fulfil the same function and the system boundaries and functional unit are clearly defined.

What is the difference between an LCA and a carbon footprint?

The LCA is broader: it covers multiple impact categories, whereas the carbon footprint measures only greenhouse gas emissions.