Metro Paws’ Poopy Packs use EPI additive with polyblend. The EPI additive is designed to control and manage the lifespan of plastics and reduce their footprint in the environment. The unique mix of polyblend and additive allow the Poopy Packs to degrade at a controlled rate when the bags are exposed to photo (sunlight), thermal (heat) and/or mechanical stress in the presence of oxygen and causes the plastic to ultimately degrade in the presence of microorganisms, moisture and oxygen into environmentally benign products within a few months. This process causes the molecules to become hydrophilic (water- attracting) and small enough to be ingestible by microorganisms, setting the stage for biodegradation to begin. This process allows for Metro Paws Poopy Packs to be given the official classification of ASTM 6954 for degradation.