Polymers Concepts , Properties, Uses & Sustainability: Part 2

A: The hard boundary is 'operational state'. ISO 14644 ties classification to particle counts measured while equipment runs. Scale-up alters shear rate and melt fracture frequency, which can elevate airborne particles even if the room layout is unchanged.

A: The hinge value is the 40°C delta. Applying volumetric expansion once gives ~2.6% volume increase, which drops density from 0.74 to roughly 0.72 g/cm³. Doubling the coefficient or ignoring phase behavior leads you astray.

A: The key threshold is oxygen concentration, not pressure. Pressure trips still protect MAWP, but they don't detect ppm-level oxygen ingress that can seed peroxide chemistry in reactive polymers.

A: The boundary is molecular size. Filtration removes solids, not absorbed organics. EFSA focuses on diffusion and desorption behavior inside the polymer, which only a surrogate challenge demonstrates.