What is ISO 14040/44? The Complete Guide to LCA Standards

Life Cycle Assessment has become essential for businesses measuring their environmental impact. But conducting a credible LCA requires following international standards. ISO 14040 and ISO 14044 provide the framework that makes LCA studies reliable, comparable and trusted globally.

If you’re investigating LCA for your products, understanding these standards is your first step towards robust environmental assessment.

Understanding ISO 14040 and ISO 14044#

ISO 14040 and ISO 14044 work together as the foundation of all Life Cycle Assessment studies. Think of them as the instruction manual for conducting LCA that ensures quality and consistency worldwide.

ISO 14040 provides the principles and framework. It defines what LCA is and establishes the overall structure for conducting assessments. Published initially in 1997 and revised in 2006, it sets out the backbone of the LCA process.

ISO 14044 delivers the detailed requirements and guidelines. Building on ISO 14040’s framework, it specifies exactly how to implement each step of an LCA study. It replaced three earlier standards (ISO 14041, 14042, and 14043) in 2006, consolidating all methodological requirements into one comprehensive document.

Together, these standards ensure that when someone conducts an LCA in Newcastle, Tokyo, or São Paulo, they’re following the same fundamental approach.

The Four Phases of LCA According to ISO Standards#

The ISO standards define LCA through four interconnected phases. Each phase feeds into the others, creating an iterative process that refines and improves the assessment.

1. Goal and Scope Definition#

This phase establishes why you’re conducting the LCA and what you’ll include. The standards require you to clearly define:

• The intended application and reasons for carrying out the study
• The functional unit (what exactly you’re measuring)
• System boundaries (where your assessment starts and stops)
• Data quality requirements
• Any assumptions and limitations

Your goal might be improving product design, supporting marketing claims, or meeting regulatory requirements. Each purpose shapes how you’ll conduct the rest of the assessment.

2. Life Cycle Inventory Analysis (LCI)#

The inventory phase involves collecting all input and output data for your product system. This means quantifying:

• Raw materials and energy consumed
• Emissions to air, water and soil
• Waste generated
• Products and co-products produced

ISO 14044 provides detailed guidance on data collection, calculation procedures, and allocation methods when processes produce multiple products. The standard recognises that data quality varies, so it requires documentation of data sources and their limitations.

3. Life Cycle Impact Assessment (LCIA)#

LCIA translates your inventory data into potential environmental impacts. The standards require three mandatory elements:

• Selection of impact categories (such as climate change, acidification, eutrophication)
• Classification – assigning inventory results to impact categories
• Characterisation – calculating category indicator results using science-based models

You might calculate that your product contributes 2.5 kg CO₂ equivalent to climate change, 0.3 kg SO₂ equivalent to acidification, and so on. ISO 14044 ensures these calculations follow accepted scientific methods.

4. Life Cycle Interpretation#

The interpretation phase evaluates your results to reach conclusions and recommendations. The standards require:

• Identifying significant issues from your inventory and impact assessment
• Completeness, sensitivity and consistency checks
• Conclusions that align with your defined goal and scope
• Clear communication of limitations

This phase connects your technical results to practical decision-making.

Key Principles That Guide Every LCA#

ISO 14040 establishes seven fundamental principles that shape how LCA studies are conducted:

Life Cycle Perspective – Consider the entire life cycle from raw material extraction through production, use, and disposal. This prevents shifting environmental burdens between life cycle stages.

Environmental Focus – LCA addresses environmental aspects and impacts. Economic and social aspects typically fall outside the scope unless specifically included.

Relative Approach – All results relate to the functional unit. If you’re assessing packaging that protects 1 litre of product for 6 months, all impacts are calculated relative to that function.

Iterative Approach – LCA phases interact and inform each other. Initial results might reveal you need to adjust your system boundaries or collect additional data.

Transparency – Document all choices, assumptions and limitations. Others should understand exactly how you reached your conclusions.

Comprehensiveness – Consider all relevant environmental issues to identify potential trade-offs between impact categories.

Priority of Scientific Approach – Base decisions on natural science where possible. Where science doesn’t provide clear answers, document your value choices.

Why ISO Compliance Matters for Your LCA#

Following ISO 14040/44 isn’t legally mandatory, but it’s become the expected standard for credible LCA studies. Here’s why compliance matters:

Credibility and Trust#

ISO-compliant LCAs undergo rigorous quality checks. When stakeholders see your study follows international standards, they know the results meet globally accepted criteria for accuracy and completeness.

Comparability#

Standards ensure different studies use consistent methods. This lets you meaningfully compare your product’s performance against alternatives or track improvements over time.

Avoiding Greenwashing#

With increasing scrutiny of environmental claims, ISO-compliant LCAs provide the robust evidence needed to support your sustainability communications. The standards require transparency about limitations and uncertainties.

Regulatory Alignment#

Many environmental regulations reference ISO 14040/44. The EU’s Product Environmental Footprint method, CBAM requirements, and various national standards all build on these ISO foundations.

International Recognition#

ISO standards are recognised globally. Whether you’re exporting products, seeking international funding, or working with multinational supply chains, ISO compliance speaks a universal language.

Critical Review Requirements#

ISO 14044 specifies when and how LCA studies need independent verification. Critical review becomes mandatory when:

• Results will be used for comparative assertions disclosed publicly
• The study will support public environmental claims
• Stakeholders request independent verification

The review process can involve:

• Internal or external expert review
• Review by interested parties
• Panel review including stakeholders

Reviewers verify that your study meets all ISO requirements for methodology, data, interpretation and reporting. They don’t validate your chosen goals but ensure your methods align with the standards.

Common Challenges in Meeting ISO Standards#

While the standards provide clear structure, implementing them presents practical challenges:

Data Availability#

ISO 14044 requires comprehensive data collection, but real-world data gaps are common. The standards allow for justified assumptions and data proxies, but these must be clearly documented.

Allocation Procedures#

When processes produce multiple products, you need to allocate environmental impacts between them. ISO 14044 provides a hierarchy of allocation methods, but choosing and justifying your approach requires expertise.

System Boundary Decisions#

Deciding what to include or exclude affects your results. The standards require clear justification for boundary choices, balancing completeness with practical constraints.

Impact Method Selection#

Multiple scientifically valid impact assessment methods exist. ISO doesn’t prescribe which to use, so you must select and justify methods appropriate for your goal and geographic scope.

How ISO 14040/44 Connects to Other Standards#

These foundational standards link to numerous related frameworks:

• ISO 14025 – Environmental Product Declarations (EPDs) must be based on ISO 14040/44 compliant LCAs
• ISO 14067 – Carbon footprint quantification follows ISO 14040/44 principles with specific climate requirements
• EN 15804 – Construction product EPDs build on ISO 14040/44 with sector-specific rules
• ISO 14020 series – Environmental labels and declarations often require ISO-compliant LCA data

Understanding ISO 14040/44 provides the foundation for navigating this broader ecosystem of environmental standards.

Practical Implementation with Decerna#

At Decerna, we apply ISO 14040/44 standards using openLCA software and established databases like Ecoinvent. Our approach ensures your LCA meets international requirements whilst remaining practical and actionable.

We’ve developed expertise across sectors, from healthcare equipment to renewable energy infrastructure. Whether you’re seeking InnovateUK funding, preparing for CBAM compliance, or developing EPDs, we ensure your LCA follows ISO standards rigorously.

Our experience shows that ISO compliance doesn’t mean complexity. With proper planning and expert guidance, you can conduct LCAs that are both scientifically robust and business-relevant.

Getting Started with ISO-Compliant LCA#

Beginning your LCA journey with ISO 14040/44 compliance requires:

1. Clear objectives – Define what you want to achieve before starting
2. Adequate resources – Budget for data collection and potential external review
3. Expert support – Work with practitioners who understand both standards and practical application
4. Quality data sources – Identify primary data needs and acceptable secondary sources
5. Documentation systems – Prepare to record decisions, assumptions and data sources

The standards provide flexibility within their framework. Your LCA can be screening-level or comprehensive, cover single products or entire portfolios, focus on specific impacts or assess comprehensively. What matters is that your choices align with your goals and follow ISO requirements.

Conclusion: Standards That Enable Credible Environmental Assessment#

ISO 14040 and ISO 14044 transformed LCA from varied approaches into a globally consistent methodology. They don’t make LCA simple, but they make it systematic, transparent and trustworthy.

For businesses serious about understanding and reducing environmental impacts, these standards provide the essential framework. They ensure your environmental assessments withstand scrutiny, support decision-making, and enable meaningful improvements.

Whether you’re beginning your first LCA or refining existing assessments, ISO 14040/44 compliance ensures your efforts deliver credible, actionable results that stakeholders trust.

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Need support conducting an ISO-compliant LCA? Decerna provides expert Life Cycle Assessment services following ISO 14040/44 standards. Contact us to discuss your assessment requirements.