A PRACTICAL GUIDE TO EPD

PART TWO: INTERPRETING GWP VALUES

GWP is closely connected to a product’s Life Cycle Analysis (LCA), which considers all the factors involved in the entire production process.

In fact, if we talk about emissions, we must be complete and uncompromising: we must consider both the direct emissions intrinsic to the product and the indirect ones that may occur during the production, transport, use and disposal of the product.

The life cycle is analyzed by dividing it into standard phases common to all EPDs:

As displayed above , the LCA monitors the product throughout its life: it starts from production (Product Stage, A1-A3) and ends with demolition (End of Life Stage, C1-C4), also providing for the possibility of reuse and recycling (D).

Where can I find the GWP values in Artigo’s EPDs?

Under the section 3.1 Life Cycle Assessment Results, a Life Cycle Impact Assessment Analysis table is presented, where the “GWP – Total” data is located.

As you can see, this table shows the values of all phases of LCA, from phases A to D.

So, how do you compare it between products?

A lower GWP value indicates a lower environmental impact. For a correct comparison, it is essential to verify that the EPDs use the same calculation methodology (“PCR” or Product Category Rule) and belong to the same product category.

How to Interpret Numbers in Scientific Notation

In technical documents, numbers can be expressed in scientific notation using the letter “E” to indicate the power of 10. The “E” stands for “exponent” and represents the multiplication by a power of ten. For example:

2E0 means 3.2 × 10⁰ = 3.2
2E-1 means 3.2 × 10⁻¹ = 0.32
2E-2 means 3.2 × 10⁻² = 0.032

Let’s talk about Cradle to Gate

The best way to perform product-to-product comparisons is by examining its Cradle to Gate values (A1-A3 or “Product Stage”).

What does Cradle to Gate include:

A1: Raw Material Extraction
A2: Transportation of raw materials
A3: Production processes

A1, Raw Material Extraction, is typically the biggest contributor to GWP. Below, is a graphic representation of A1 for 3 mm Uni and Kayar, from the GAIA EPD.