What is the difference between your EPD and your PHD?

The Yuantai Derun hollow section EPD and the PHD answer different questions and are used for different credits. The EPD, to EN 15804 and ISO 14025, is a life cycle assessment: it quantifies environmental impact, and the figure most buyers want from it is global warming potential, which for us is 1.95 to 2.21 kg CO2e per kilogram over modules A1 to A3.

The PHD, a Product Health Declaration rated Platinum, looks instead at what is inside the material: alloying elements, residual process chemicals and surface treatment residues. It speaks to material transparency and to human health rather than to carbon.

In practice this means the EPD carries the LEED environmental declarations credit and the PHD carries the material ingredients credit. Teams sometimes assume one document covers both, which is the most common misunderstanding we see. Both are published by Global GreenTag. Further detail is on our EPD certification page.