Understanding Life Cycle Assessment (LCA): From Cradle to Grave

Ask most people how environmentally friendly a product is and they will think about the factory that made it. Life Cycle Assessment exists because that instinct is usually wrong. For many products, the majority of the environmental impact sits somewhere else entirely - in raw material extraction, or in how the product is used, or in what happens when it is thrown away.

What LCA measures

An LCA follows a product across its whole life and quantifies the environmental burden at each stage:

• Raw material extraction
• Processing and manufacturing
• Transport and distribution
• Use by the customer
• End of life - disposal, recycling or recovery

Crucially, it does not measure carbon alone. A full LCA covers multiple impact categories, which is what allows it to expose trade-offs: a change that lowers emissions may raise water consumption, and without LCA that shift stays invisible.

The standards

LCA is governed by two international standards. ISO 14040 sets out the principles and framework; ISO 14044 specifies the requirements and guidelines. A study that does not follow them is an estimate, not an LCA, and will not stand up when a customer's technical team reviews it.

The four phases

1. Goal and scope definition

The most consequential phase, and the one most often rushed. Two decisions shape everything:

• Functional unit - what exactly you are measuring, expressed as a unit of function rather than a unit of product. Not "one litre of paint" but "the paint required to cover one square metre for ten years". This is what makes two products genuinely comparable.
• System boundary - where the study starts and stops.

2. Life Cycle Inventory (LCI)

The data collection phase, and by some distance the most laborious. Every input and output is quantified - energy, water, raw materials, emissions to air and water, waste. Primary data from your own operations is preferred; established databases fill the gaps upstream.

3. Life Cycle Impact Assessment (LCIA)

Inventory data is translated into impact categories - climate change, acidification, eutrophication, resource depletion, water use and others. This is where a long list of flows becomes something a decision maker can act on.

4. Interpretation

Results are examined for significant issues, checked for completeness and consistency, and tested for sensitivity to assumptions. Honest interpretation includes stating limitations - an LCA that reads as uniformly positive usually signals a study that was scoped to produce that answer.

Why companies commission LCAs

• Customer requirement. Large buyers increasingly ask for product-level environmental data as a condition of supply.
• Credible claims. Marketing statements about sustainability need evidence. An LCA provides it and reduces greenwashing exposure.
• Design decisions. LCA frequently overturns intuition about where impact actually sits, which redirects improvement effort to where it matters.
• Regulatory direction. Product-level environmental disclosure requirements continue to expand in export markets.

LCA and carbon footprint are not the same thing

A product carbon footprint measures greenhouse gas emissions only. An LCA measures multiple impact categories, of which climate change is one. A PCF is effectively a single-issue LCA - which is why an organisation that has completed an LCA can usually produce a PCF from the same inventory at modest additional cost.

The same inventory also supports Scope 3 reporting and strengthens the Environment theme of an EcoVadis assessment. Data collected once, used several times.