Firstly: DIN standards have no legitimate character.
Secondly: DIN standards are optional standards.
Thirdly: DIN standards get a legitimate character as soon as a law is referring to them.
Fourthly: DIN standards are getting legislated by working parties of the German Institute of Standardization and their currency is getting checked every five years, if necessary they get amended or even abandoned.
Requirements for fuel oils are listed in the DIN ISO 51603 and splitted up in five categories: Fuel oil EL (extra-light), fuel oil S (heavy), fuel oil R (re-refined), fuel oil SA (low sulphur) and fuel oil EL A (extra-light alternative).
In this case fuel oil EL is not important because it is no industrial fuel oil. Fuel oil R is recycled waste oil – not really our business. The standards for heavy fuel oils are the important part for us and here especially their viscosity, density, heating and calorific value as well as their sulphur content. Mentioning the data tables of the DIN institute at this point would be idle. You can get them right out of the internet onto your desk in just one, two, three clicks via google.