Quality & testing
UCO quality: FFA, moisture, impurities and MIV
Read UCO quality parameters correctly: free fatty acids, moisture, insoluble impurities, MIV, methods and contractual acceptance.
Direct answer
FFA describes free fatty acid content on a stated reporting basis. Moisture and insoluble impurities are separate measurements. MIV is commonly shorthand for moisture, impurities and volatile matter, but the contract must define the exact components and methods to avoid overlapping results.
FFA and acid value are different reported quantities
An acidity report must state whether it gives acid value or a conventionally calculated acidity percentage and which reporting basis is used. ISO 660 covers acidity measurement. Do not treat a percentage and an acid value as interchangeable or convert them without the stated basis.
The receiving plant decides its acceptable limits. A quoted FFA target does not prove the result of a lot. Ask for a certificate identifying the sample, lot, method and date.
Define the combined MIV requirement
ISO 662 covers moisture and volatile matter; ISO 663 covers insoluble impurities. If a contract uses a combined MIV limit, specify how each result contributes to that total. Do not add a separate water result to a moisture-and-volatiles result without checking overlap.
Report each value with units, method and basis. A buyer may need additional contaminants assessed for its process. A sample photograph or clear appearance cannot establish the analytical values.
Translate a specification into an acceptance plan
For every parameter, identify the agreed limit, laboratory method, sampling point and decision rule. Separate indicative targets on a TDS from measured results on a COA. If the analytical basis is missing, clarify it before comparing offers.
- FFA reporting basis stated
- Moisture and volatiles method identified
- Insoluble impurities result identified
- Combined calculation defined without double counting
- Buyer-specific limits and acceptance procedure agreed
Buyer questions
Does low FFA prove that UCO is authentic?
No. An acidity result is a quality measurement. Origin and chain-of-custody evidence must be assessed separately.
Is one MIV limit suitable for every buyer?
No. Define the components and methods and use the receiving plant’s accepted specification.
Sources and evidence
Primary references support the stated technical definitions. Procurement checklists are editorial guidance, not evidence of a specific lot, shipment or certification.
- ISO 660:2020 — Acid value and acidity ↗
- ISO 662:2016 — Moisture and volatile matter ↗
- ISO 663:2017 — Insoluble impurities ↗
Confirm laboratory methods, commercial terms and applicable requirements with the buyer and qualified advisers before contracting. No guide establishes stock availability or company certification.
Continue your assessment
UCO certificate of analysis vs technical data sheet
Understand COA and TDS documents for used cooking oil: measured lot results, indicative specifications, units and evidence gaps.
Used cooking oil sampling: a buyer’s checklist
Plan representative UCO sampling with lot identification, sealed retained samples, laboratory instructions and an agreed acceptance point.
Filtered UCO vs pretreated UCO: questions for suppliers
Specify what filtration and pretreatment mean in a UCO offer and request analytical evidence of the material actually delivered.
Discuss a documented UCO requirement
Send the quantity, loading and destination places, intended use, quality limits and required documents. Our trading desk can assess the file.
Discuss a documented UCO requirement →