The Oil Spill Analysis service is awarded the accreditation by ENAC (ISO 17025) and based on the chemical characterization of oil spills in the aquatic environment according to the CEN 15522-2 legal standard, which is based on the principles of environmental forensics. The products capable of being assayed include crude oil and its derivatives which contain a significant proportion of hydrocarbons with a boiling point higher than 200ºC. The method is based on a comparative study of ratios of molecular markers between the different candidate sources and the contaminated samples. Even though the laboratory has a great expertise in the determination of a wide range of environmental samples, the accreditation scope is specifically limited to seawater, sampling nets, emulsioned samples and tar balls. In addition, persistent chemical floaters on the sea surface (vegetable oil, plasticizers, FAMEs, siloxanes) can be also analyzed under the ENAC accreditation based on an internal lab methodology. The service is responsible for all the steps in the analytical process of the oil spills except sampling and transportation.