Define the material and intended use
Start with the manufacturer, production site, product identifier, viscosity cut, declared API group and controlled supplier specification. API Groups I, II and III use saturates, sulphur and viscosity index; those properties do not by themselves establish volatility, cleanliness, oxidation response or suitability.
ASTM D6074 guides selection of physical, chemical and toxicological characterisation methods for virgin and re-refined hydrocarbon base oils. It does not provide universal acceptance limits and does not cover finished lubricants. The buyer and seller must connect limits and frequency to the intended application.
- Control the manufacturing site and product identity.
- Define methods, units and acceptance criteria before testing.
- Separate base-oil classification from performance claims.
Establish a defensible consistency envelope
Qualification should examine representative production across relevant feedstock and operating variation rather than a supplier's best sample. The dataset needs test methods, laboratory competence, precision, detection limits, acceptance limits and an out-of-specification process.
ATIEL Issue 26 calls for verifiable feedstock screening, approved processing conditions, documented change control, routine quality control and auditable procedures. The RRBO manufacturer remains responsible for maintaining material within its declared API classification.
- Review multi-batch trends for agreed critical properties.
- Control transport, storage and commingling.
- Define change-notification and requalification triggers.
Close the gap between analysis and performance
ASTM D5185 can screen selected elements, but particle size affects the result and larger insolubles can be under-reported. No single analytical method proves complete cleanliness.
Base-stock acceptance must be followed by application-relevant formulation work. Relevant properties can include composition, contamination, volatility, viscosity, oxidation response, deposit tendency and pour point, followed by finished-oil behaviour such as sludge, foam, elastomer compatibility, homogeneity and stability.
- Do not invent a universal batch-count rule.
- Do not copy contaminant limits without application or regulatory basis.
- Use controlled copies of standards for laboratory execution.
Read the underlying documents.
- ASTM D6074-15(2022): hydrocarbon base-oil characterisationASTM International ↗
- ASTM D5185-26: multielement analysisASTM International ↗
- Code of Practice, Issue 26ATIEL ↗
- API 1509, 24th EditionAmerican Petroleum Institute ↗
Source links and status were reviewed on 31 July 2026. Standards and regulations may be revised after publication.