Quality & testing
UCO contaminants: phosphorus, metals and buyer-specific testing
Go beyond FFA and MIV when reviewing used cooking oil: agree contaminant parameters, test methods, detection limits and receiving-process acceptance.
Direct answer
FFA and MIV do not describe every contaminant relevant to UCO processing. A receiving operator may require phosphorus, metals or other process-specific measurements. Ask it to define the analytes, methods, units and limits for the actual facility. A filtered appearance or a low FFA result does not replace those measurements.
Start with the receiving process
Identify which fuel-production route and pretreatment facility will receive the material. The NREL feedstock-impurities report discusses contamination and pretreatment considerations for aviation-fuel production. It is a technical reference rather than a universal UCO purchase specification.
Ask the receiving operator which contaminants need reporting. Record each parameter individually rather than using a general phrase such as clean oil. Different facilities can require different preparation and acceptance evidence.
Require a method and a reporting limit
A useful laboratory result identifies the sample, analyte, unit, method and detection or quantification limit where relevant. ISO 10540-1 describes a phosphorus determination method for fats and oils; the buyer and laboratory must confirm suitability for the sample and required range.
Do not treat a result reported below a laboratory limit as proof that the substance is absent. Clarify whether the method can measure below the contractual acceptance threshold. Compare results only when units and reporting bases are compatible.
Test the material after the relevant treatment
Record settling, filtration or other pretreatment and the point at which sampling occurred. A process name does not prove the final concentration of a contaminant. Confirm whether the analysed sample represents the material intended for loading.
Agree the additional testing plan before pricing treatment or accepting a batch. The guide supplies no universal phosphorus or metals limit and no statement that a particular UCO lot is suitable for a production facility.
- Receiving process identified
- Required analytes listed separately
- Units and analytical methods agreed
- Laboratory reporting limits checked
- Sample linked to final loading material
Buyer questions
Does filtered UCO automatically meet phosphorus limits?
No. The treatment description does not replace a measured result for the final material and the receiving operator's acceptance criteria.
Does a low FFA result prove that metals are acceptable?
No. Acidity and metals are different measurements. Request the tests required for the intended receiving process.
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 10540-1:2003 — Phosphorus determination ↗
- NREL — HEFA state-of-industry report, revised September 2026 ↗
- FOSFA — Contractual methods of sampling ↗
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 quality: FFA, moisture, impurities and MIV
Read UCO quality parameters correctly: free fatty acids, moisture, insoluble impurities, MIV, methods and contractual acceptance.
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.
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.
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 →