ISO 22095 Mass Balance Chain of Custody Audit Requirements
ISO 22095 mass balance audits demand strict site boundaries, verified baseline yield conversions, and zero negative credit balances across accounting periods.
System Boundary Geometry
Meaning
The defined physical and process limits of a manufacturing system determine which polymer flows and operations are included in a mass balance calculation. This system boundary geometry establishes the exact points where raw materials enter the certified process and where finished products exit. Processors define these limits to ensure that only relevant compounding, extrusion, and molding steps are audited.
It prevents the inclusion of unrelated operations that could distort the mass balance calculations.
Material Efficiency
Defining the boundaries is necessary to track the physical transformation of the polymer through the plant. The system boundary geometry dictates which extrusion lines, blending silos, and regrind grinders are included in the certified loop. When a processor outlines these boundaries, they ensure that all sources of contamination or material dilution are monitored.
This precision is critical for maintaining the high purity levels required for food-grade or medical molding applications. It also prevents the accidental dilution of certified recycled resins with conventional polymers during complex material handling stages.
Production Limit
The physical arrangement of the machinery restricts the paths that certified materials can take. The system boundary geometry prevents the routing of certified resins through non-certified equipment or storage areas. If a batch of certified polymer is processed outside the defined boundaries, it loses its certified status.
This operational constraint requires strict separation of production lines and dedicated piping for sustainable feedstocks.
Financial Consequence
Changes to the plant layout can require expensive recertification of the mass balance system. If the system boundary geometry must be modified, the processor must pay for an audit. This constraint means that plant designs must be planned carefully to avoid disruption.