Iodine Value (IV)

IV is the most widely use test to identify the oil's purity and check contamination and/or adulteration

It is a measure of the unsaturated fatty acid in the oil (see oil composition)

Typical IV value

Coconut Oil - 9
Palm Kernel Oil - 18
Palm Oil - 52
Palm Olein - 56
Palm Stearin - 25 to 33
Rapeseed Oil - 110
Maize Oil - 103 - 125
Soyabean Oil - 130
Linseed Oil - 180



The test method is fast, reliable and especially useful in identifying mixing of high IV oil into loo IV. The other way round could be tricky and further test such as FAC by GLC is required (Fatty acid composition by Gas-Liquid Chromatography). Non Chemist trader just stick to GLC or GC as it is commonly understood, tough technically no correct. GLC or GC is a testing method


Some typical example of IV test for contamination

1. CPKO in CCNO

There are no standard trade specification for CCNO - range from 10.5 max to 12 max while typical value of Indonesia/Phillipine origin is around 9. In those day when there is good price disparity and when the spec is 12 max, inevitable 5-10% CPKO went into CCNO (yes - you can calculate by numerical ratio the resultant mixture IV)

2. Palm Oil IV 50 - 55 while typical is 51 - 52. Unfortunately CPO domestic spec has no IV spec - when you received IV 50.1 and complained, seller will claimed it is bottom stock cargo, or some 5% stearin is being added.

3. Maize Oil has wide range of IV due to origin - some soya oil will added in Maize Oil due to price disparity

4. Soyaoil from south america - watch out linseed contamination when yr IV is excessively high