Life Cycle Assessment (LCA)

LCA is a method to quantitatively assess the environmental impact of a product or service from cradle-to-grave. This means from the production of the raw materials, through the production, distribution, use, disposal and recycling of that product. We refer to these as the different phases of the life cycle of a product or service.

LCA is a process of evaluating the environmental performance over the entire period of its life. It can be used to study the environmental impact of a product, or even better, the function of the product.

LCA's key elements are:

  (1) identify and quantify the environmental loads involved
        e.g. the energy and raw materials consumed as well as
        the emissions and wastes generated

  (2) evaluate the potential environmental impacts of these loads

  (3) define the options for improvement of the environmental performance.

• Results

The result of an LCA is an environmental profile consisting of a number of potential environmental effects. Examples are global warming, depletion of the ozone layer, acidification and human toxicity.
 

Environmental profile

The value of the environmental effect category is expressed in equivalents. For global warming the equivalent is the potential contribution of 1 kg of carbon dioxide (CO₂) to global warming. This is set to 1. All other emissions with a contribution to global warming are expressed in the same unit to their relative effect compared to CO₂. An example is given below.

Global warming potential (GWP)
1 kg carbon dioxide = 1 kg GWP-equivalents
1 kg methane = 24 kg GWP-equivalents
----------------------------------------------------------Total = 25 kg GWP-equivalents

Improvement options
The major contributions can be defined using different entries in the life cycle:
• the phases
• the materials and processes
• the substances

This gives you the knowledge where to start to improve the environmental performances. It also tells you who to involve.
 

Comparisons
Different options and scenarios can be compared:
• products or innovations
• policies
• recycling options.

This gives insight into the effect of possible changes and variations.

Prioritizing
All values can be given meaning by relating the impact to the total impact in the U.S. If we apply this to all environmental effects we gain insight in the effects that contribute the most to the U.S. environmental profile. With this information we can define which improvement options will lead to the best result for the environment. In LCA language this is called normalization.

This gives insight in the most important potential environmental effects.

• Tools

Specialized software tools are used to perform LCAs. The life cycle is modeled in the software. Extensive databases are used with LCA data for commonly used processes such as power generation and transport.
 

• Methodology

Harmonization and standardization help to improve the comparability of different LCAs.

Standardization is available through ISO. Relevant standards are:
• ISO 14040 Principles and framework
• ISO 14041 Goal and Scope Definition 
• ISO 14042 Inventory Analysis
• ISO 14043 Interpretation
• ISO 14025 Type III environmental declarations

Standardization is also available when concerned parties establish a product of product group specific framework. This is called a document with product category rules (PCR). We are developing a PCR for the U.S. for the building sector to arrive to a harmonized format for environmental product declarations (EPD).
read more about EPDs
 

  Further reading

What can LCA do for you according to the UNEP
ISO technical committee on sustainability and construction

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