Iodine number

OELCHECK test instrument: Accessories in accordance with DIN
Sample quantity: 2 ml
Unit: none
Test result: iodine number
Result range: <10 - 200
Analysis for: Bio oils to differentiate between saturated and unsaturated ester oils
Brief description:

The iodine number indicates the parts of halogens in grams absorbed by grease or native oils, calculated as iodine. In order to determine the iodine number, excess iodine is back-titrated with a sodium thiosulphate solution using starch solution as an indicator. Consumption of the titrant indicates the iodine number.


The iodine number is a measure for the amount of unsaturated compounds in a fluid. A low iodine number indicates that the fluid contains few unsaturated compounds and is therefore significantly more stable when exposed to periods of oxidation than a fluid with a higher iodine number.

Oils are described as "saturated" when their iodine number is <10. However, unsaturated fluids have a much higher iodine number. Typical rapeseed oils, for example, have an iodine number of approximately 120.

Underlying test standard: DIN EN 14111, ASTM D5554