Run the safety and identity gate before unloading
The first review combines load identity, source history, container condition, temperature, visible free water, sludge and phase separation. Closed-cup flash point can support screening where volatile fuel or solvent contamination is plausible.
An unexpectedly low flash point or unidentified load should be quarantined. Odour is not an acceptance test, and flash point neither identifies the substance nor quantifies fuel or solvent concentration. Confirmatory analysis should match the suspected material and applicable legal requirements.
- Inspect seals, labels and container integrity.
- Record visible water, sludge and phase separation.
- Choose confirmatory methods before releasing a quarantined load.
Match each question to a suitable method
Water methods must suit the expected range and matrix. Coulometric Karl Fischer analysis can quantify lower concentrations but has recognised chemical interferences. Qualitative glycol screening can miss degraded or oxidised glycol.
ICP-AES can rapidly measure selected dissolved or finely dispersed elements, but larger insoluble particles may be under-represented. Sodium, potassium or boron patterns can prompt a coolant investigation; they are not definitive proof by themselves.
- Use chromatographic or another validated method when volatile identity or concentration matters.
- Validate the water procedure for the actual ULO matrix.
- Interpret metals alongside filtration, particle and source-history evidence.
Convert results into controlled disposition
The acceptance system needs defined accept, conditional-accept, quarantine and reject routes. Limits must reflect plant capability, safety controls, permits, intended products and residue-management consequences rather than copied generic numbers.
Decision rules should address analytical uncertainty, repeat testing and referee analysis near a limit. Retain samples support disputes and root-cause work, while trending by generator, collector, route, oil family and season can expose deterioration before it becomes a major incident.
- Do not confuse a screening result with complete risk assessment.
- Record the technical and legal basis for every limit.
- Preserve the disposition and destination of rejected material.
Read the underlying documents.
- ASTM D93: flash point by Pensky-Martens closed cupASTM International ↗
- ASTM D6304: water by coulometric Karl Fischer titrationASTM International ↗
- ASTM D2982: detection of glycol-base antifreezeASTM International ↗
- ASTM D5185: multielement determination by ICP-AESASTM International ↗
Source links and status were reviewed on 31 July 2026. Standards and regulations may be revised after publication.