Mass balance and batch-based traceability represent two different, often complementary, methods of tracking materials through a supply chain, with the primary difference lying in whether the materials are physically separated (batch) or mixed (mass balance) during production.
• Batch-based Traceability (Segregation): Ensures that specific, certified material remains separate from non-certified material throughout the entire chain. Each batch can be traced back to its specific origin using a Raw Material Batch ID or a Digital Product Password
• Mass Balance: Allows certified and non-certified materials to be mixed, but requires that the volume of certified material entering the process matches the volume of certified material exiting, accounting for conversion losses. MSC allows only mixing of batches of fish from various MSC certifications, as long as the mass balance annually adds up.
Mass Balance Traceability
Mass balance is a bookkeeping method used when physical separation of materials is difficult or too costly, such as in chemical production, oil refining, or food processing.
• How it works: If a company purchases 100 tons of sustainable material and 900 tons of conventional material, it can produce 1,000 tons of product. However, through mass balance, they can claim 100 tons of “certified sustainable” output (plus or minus processing losses).
• Key Features:
o Mixing allowed: Certified and conventional materials are blended.
o Bookkeeping: Records are kept of all incoming and outgoing materials (a “mass balance ledger”).
o Certification: Requires independent auditing to verify that output does not exceed input.
o Flexibility: Ideal for high-volume, continuous manufacturing processes where physical separation is impractical.
• Drawbacks: The final product might not actually contain any of the certified raw material, but it carries the associated environmental/ethical credentials.
Batch-Based Traceability (Product Segregation)
This method, often referred to as “Identity Preserved” or “Segregation,” requires that certified materials are kept separate from conventional materials at every stage.
• How it works: A batch of certified raw material is tracked from the farm or supplier, through transportation, processing, and finally to the end customer.
• Key Features:
o Physical Separation: No mixing occurs between certified and non-certified products.
o High Assurance: The end-user is guaranteed that the specific product they receive is 100% derived from the certified source.
o Increased Cost/Complexity: Requires dedicated storage, transport, and production lines, making it more expensive.
• Drawbacks: Difficult to implement in complex supply chains with continuous, mixed-feedstock processes.
Comparison Summary
|
Feature |
Mass Balance |
Batch-Based (Segregation) |
|
Physical Separation |
No (Mixing allowed) |
Yes (Required) |
|
Traceability Level |
Administrative/Bookkeeping |
Physical/Specific |
|
Costs |
Lower (Uses existing infrastructure) |
Higher (Requires dedicated facilities) |
|
Best Used For |
High-volume, continuous processing (Chemicals, Oils) |
Niche products, specific certifications |
|
Precision |
Certified volume matches total inputs |
Full, chain-of-custody tracking |
When to Use Which?
• Mass Balance is used to scale up the use of sustainable alternatives (like recycled plastic or bio-based feedstock) in existing infrastructure without constructing new, dedicated, separate lines.
Batch-based is used when a product must be 100% verified as coming from a single source (e.g., organic, specific high-value sourcing).