Long term behaviour of plastic material under stress is a critical property in several applications. Plastic components in applications like infrastructure or automotive often need to withstand a certain stress over very long time. Also in packaging application this is relevant in some cases.
ISO 899-1 - Tensile creep behaviour
ISO 16770 - FNCT Full notch creep test (FNCT)
ASTM D 1693 - ESCR Bell test (environmental stress cracking - method B)