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2021 Proficiency Test (PT) on Naphtha 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 iis21N01 here: the letter of instructions.

Download the instuctions for iis21N01Hg here: letter of instructions for Hg.

Download the instuctions for iis21N01AsPb here: letter of instructions for AsPb.

Download the instuctions for iis21N01DVPE here: letter of instructions for DVPE.


Summary of this proficiency test:


On 10 March 2021 the proficiency test on Naphtha started with 90 participants from 38 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: Organic Chlorides, Color Saybolt, Copper Corrosion 3hrs at 50°C, Density at 15°C, Distillation, Mercaptan Sulfur as S, Sulfur, Mercury as Hg, Arsenic as As, Lead as Pb, Total Vapour Pressure and DVPE. 


The deadline for reporting results is set on 16 April 2021. 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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