Outline headache not easily break down PBS A.contact microorganisms enzymes smaller pieces into water Co2 B.1.safer 90%/degraded in 90 days/shorter in a dump 2.more heat resistant a.melt at 60C b.shape retained up 100C Outline I headache not easily break down II. PBS A. contact / microorganisms / enzymes / smaller pieces / into water & CO2 B. 1. safer 90% / degraded / in 90 days/ shorter / in a dump 2. more heat resistant a. melt at 60℃ b. shape retained up 100℃