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2023 Proficiency Test (PT) on Engine Oil (used) started


The letter of instructions can be downloaded here as a pdf document. To download a document, please click the right mouse button and choose the "save as" option.


Please download the instructions for the PT iis23L08 here: the letter of instructions and the report form here

Download the instuctions for iis23L08M here: letter of instructions for Metals and the report form here


Summary of this proficiency test:


On 10 May 2023 the proficiency test on Engine Oil (used) started with 82 participants from 48 different countries. On that date, the samples were dispatched to the laboratories. Enclosed to the sample is the material safety data sheet (MSDS).

Please confirm sample receipt as soon as you have received and checked the contents of the sample package via Please enter the date of receipt and press the "save date" button.


The samples can be analyzed on:Total Acid Number, Base Number, Density at 15°C, Flashpoint PMcc, Fuel Dilution, Kinematic viscosity at 40°C / at 100°C, Viscosity Index, Kinematic Viscosity Houillon at 40°C / at 100°C, Water and over 20 elemental analysis ( Al, Ba, B, Cd, Cr, Cu, Fe, Pb, Li, Mg, Mn, Mo, Ni, K, Si, Ag, Na, Sn, Ti, V, Ca, P, Zn).  


The deadline for reporting results is set on 16 June 2023. A laboratory that reports test results after the deadline will definitely not get direct feedback in case any of its results are suspect! So be in good time to get the most out of this proficiency test.

The test results should be reported via our internet based results reporting platform A login and a password can be requested via email to





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