In order to use rapeseed oil as fuel, some physical and chemical properties of the oil must be met. The description of these properties as well as its effect on the diesel engine should be taken into account. Thus, the German norm DIN 51605 is to be followed.

This norm establishes the maximum and minimum values for the parameters selected to accept a rapeseed vegetable oil as appropriate biofuel to substitute diesel in modified engines. The parameters include some intrinsic rapeseed oil properties and some which are variable and indicate if the oil has been correctly processed. Between these properties, acid value, iodine index and oxidation time are the ones which indicate the vegetable oil degradation.