11 
Oil Spill identification - Round Robin 20045 
1. Introduction 
Note 
For literal quotations of parts of reports, 
publications and letters, In this report 
the typesetting of the text to the right Is 
used 
1.1 Invitation 
The round robin started with this invitation by email with enclosed 
letter on 19-5-2005: 
Dear all, 
RIZA (Institute for inland water management and waste water treatment) is a 
governmental institute responsible for the environmental quality of the 
surface water in the Netherlands. 
One of our tasks is the comparison of oil samples from spills with possible 
sources. 
For many years we have exchanged spill samples each year with the Dutch 
Forensic Institute (NFI) for quality assurance. The results of each exchange 
were evaluated in a report with the original reports as appendix. 
Due to questions of other laboratories we started together with BSF1 
(Bundesambt fur Seeschifffahrt und Flydrographie) last year to organize an 
(inter)national round robin. The round robin of 2004 (RR2004) was dealing 
with gas oil (diesel) samples. Fifteen laboratories of nine countries 
participated, resulting in a general report and 15 original reports as 
appendixes. The results are available on request. 
Samples and analysis method 
It is intended to use each year a different kind of sample. This year our study 
deals with three to four bilge samples (diesel-lubricating oil), which must be 
compared. 
In most Round Robins a method is prescribed. Oil Spill Identification 
however is a typical “expert” method. Analytical methods can be given, but at 
the end an expert has to take the decision based on all information. For us the 
RR is a means to inform each other how to deal with cases. 
From the results of RR 2004, it can be seen that most of the laboratories have 
an own method, although a lot of them follow more or less the Nordtest 
method. 
The CEN working group CEN/BT/TF 120 intents to finish in June an 
European guideline for sampling and oil spill identification of waterborne oil, 
based on the Nordtest method. 
So for next year we can advice to follow this guideline and discuss and 
compare the results of the laboratories that have followed it, in more detail. 
But in general each laboratory has to follow its own standard procedure for 
oil comparison. 
The resulting report should not only consist of a simple yes or no, but also a 
summary of the procedure should be given, together with detailed results and 
reasons why a decision has been taken.