Balance Mass Balance Volume Under ASC Feed Standard

Mass balance accounting rules under ASC Feed Standard

The Aquaculture Stewardship Council updated rules for mass balance volume accounting under Criterion 3.1 and Criterion 3.2 in version 1.2 of the ASC Feed Standard. This affects quality managers, compliance leads and inventory managers at certified feed manufacturing facilities. Feed mills using the Mass Balance Production Model must track incoming eligible ingredients and outgoing ASC feed through a documented accounting tool. Conformity Assessment Body auditors verify ingredient eligibility, ledger transactions and end-of-year volume reconciliations during annual audits.

The Mass Balance Production Model allows physical mixing of eligible and non-eligible ingredients during processing, provided overall quantities are monitored administratively. This results in an ASC claim on a portion of finished feed output that corresponds to the volume of eligible ingredients purchased. The accounting period for mass balance balancing covers twelve calendar months running from 1 January to 31 December. Failing to balance the ledger by the end of December or overdrawing volume past allowed thresholds indicates a non-conformity.

Auditors examine receiving dockets, supplier invoices, dispatch notes and ledger logs to verify calculations. In addition, feed mills must establish robust procedures to verify ingredient eligibility before crediting entries into the accounting ledger. Demonstrating accurate volume accounting protects supply chain integrity and prevents over-claiming certified feed volumes across global markets.

Operating the Ingredient Accounting System

Indicator 3.1.4 and Appendix 13 establish mandatory operational rules for the Ingredient Accounting System:

• Authorised access: The system must be operated by trained personnel and protected from deliberate or accidental data alteration.
• Continuous updates: Transactions must be recorded continually upon physical receipt of eligible ingredients and upon dispatch of ASC Mass Balance feed.
• Aquafeed destination filtering: Only raw material volumes physically received and destined for aquafeed production can be entered into the ledger.
• Deduction for non-aquafeed: Volumes previously entered as eligible that are subsequently re-allocated to terrestrial livestock feed must be deducted immediately.
• Yield and pre-processing adjustments: Any pre-processing weight changes greater than five percent caused by moisture extraction or waste removal must be incorporated into volume calculations.

Annual balancing summary and credit carryover

Appendix 14 sets specific rules for reconciling mass balance credits at the close of each accounting period:

• Annual 12-month summary: Feed mills must calculate an annual balancing summary reconciling carried-over volume, received eligible volume, sold ASC product and final carryover.
• Twenty-four month credit expiration: Unused eligible ingredient credits expire and must be deducted from the ledger if not allocated to feed outputs within twenty-four months of physical receipt.
• Temporary overdrawing allowance: Mills may overdraw eligible volumes during the twelve-month accounting period provided the ledger is fully balanced by 31 December.
• Unused credit carryover: Unused eligible volume remaining at the end of December can be carried over into the following twelve-month accounting period.
• Compliance tolerance window: End-of-year balance calculations permit a compliance tolerance window of up to a maximum five percent overdrawn shortfall before a non-conformity is raised.

Mandatory sourcing rule for Category 1 plant ingredients

Indicator 3.2.2 and Appendix 14 enforce specific sourcing restrictions for Category 1 plant ingredients derived from soy and palm oil. Under standard mass balance accounting, total eligible volumes can usually be substituted across different ingredient categories to meet overall targets. However, for soy and palm oil ingredients, feed mills must ensure that the volume of eligible Category 1 ingredients sourced equals or exceeds the volume of Category 1 ingredients contained in ASC feed sold. This rule prevents feed mills from substituting sustainable soy and palm oil with other plant categories, maintaining progress towards deforestation and conversion free supply chains.

Recognising potential supply delays, Indicator 3.2.2 permits a tolerance of up to five percent shortfall in Category 1 eligible ingredient sourcing during an accounting period. To utilize this tolerance, the feed mill must document the operational justification for the shortfall and compensate for the deficit through corrective sourcing in the subsequent accounting period. If the Category 1 shortfall exceeds five percent or remains uncompensated, a non-conformity is issued by the auditor.

What to do now

• Audit the Ingredient Accounting System: Review system access controls and confirm that incoming ingredient entries match physical receipt dockets and Due Diligence eligibility checks.
• Reconcile annual volume balances: Calculate the twelve-month mass balance summary for the current calendar year to ensure outgoing ASC feed does not exceed incoming eligible credits plus carryover.
• Monitor Category 1 plant ingredient volume: Compare received eligible soy and palm oil volumes against calculated inclusion rates in ASC feed sold to verify compliance with Indicator 3.2.2.
• Check credit expiration dates: Review ledger entries from previous years to identify and deduct any eligible ingredient volume older than twenty-four months.

Reference documents

• ASC Feed Standard, V1.2, Criterion 3.1, Criterion 3.2, Indicators 3.1.1, 3.1.2, 3.1.4, 3.2.1, 3.2.2, 3.2.3, 3.2.4, Appendix 5, Appendix 13, Appendix 14
• ASC Feed Standard Interpretation Manual, V1.2, Criterion 3.1, Criterion 3.2, Appendix 13, Appendix 14