ASTM D6074 Standard Guide for Characterizing Hydrocarbon Lubricant Base Oils
6. Sampling
6.1 Sampling of base oils may be required as part of the buyer/seller arrangement. If a sampling program is required, sampling in accordance with Practice D4057 or a suitable alternative may be employed.
7. Procedure
7.1 Application of Guide:
7.1.1 This guide applies only to hydrocarbon lubricant base oils. Base oils containing detectable levels of esters, animal fats, vegetable oils, or other materials used as, or blended into, lubricants are not covered by this guide.
7.1.2 The frequency and extent of testing is to be determined based upon need. A property that can be shown to have minimal variation with time, a potential contaminant that can be shown to be consistently absent or at levels below concern, or a toxicological property that is shown to be satisfactory may justify infrequent testing or no additional testing. In such cases, reporting of typical expected values may be acceptable.
7.1.3 Some of the measurements could be performed on the individual base stocks, and then, knowing the test results and the proportions of the base stock components in the base oil, test values can be calculated. Similarly, laboratory blends of base stocks in appropriate ratios could substitute for actual stream samples when sampling is not practical. This procedure should be negotiated between the base oil buyer and the seller.
7.1.4 The test methods suggested are not an exhaustive list. Many nonstandardized methods are being used in the petroleum industry, such as high-performance liquid chromatography (HPLC), supercritical fluid chromatography (SFC), and thin layer chromatography (TLC) methods for the determination of saturates content. Further, there are more complex tests available for some properties that might give equivalent or superior information. For example, estimates of dermal carcinogenic potential can be obtained from screener tests, such as Test Method E 1687 or IP 346, but the Chronic Animal Bioassay Analysis (that is, mouse skin painting assay) represents the definitive test for the determination of carcinogenicity hazard of base oils.
NOTE 1 - Local legislative and regulatory requirements may also apply when selecting the tests to be run.
7.1.5 Some of the physical, compositional, and contaminant test methods cited in Table 1 and Table 2 are utilized outside of their published scopes. If this is the case, there typically is no other more appropriate method, and industry experience has shown the test method to give acceptable results.
7.1.6 If the test method is a modification to an accepted test method, it should be identified when providing information on a base oil (for example, DXXXX Mod.).
7.2 Properties and Potential Contaminants:
7.2.1 The following tables contain suggested properties, potential contaminants, and commonly used test methods that one might want to include in a base oil evaluation.
7.2.2 Table 1 includes physical and compositional properties and test methods only.
7.2.3 Table 2 includes parameters that may relate to potential contaminants and to toxicological properties. Typical levels were compiled through a survey of base oil producers. For further details, see Research Report.
7.2.4 A discussion of the significance of each property is provided in Appendix X1.
8. Keywords
8.1 base oil; base stock; hydrocarbon; lubricants; oil
