This article was specially prepared by MPOB scientists to communicate the concern on food safety associated with the 3-Monochloropropane-1, 2-diol (3-MCPD) esters contamination of defined palm oil to palm oil millers. Although the contamination is hardly seen in crude palm oil (CPO), its significant presence in refined palm oil is a cause for concern not only for the refinery but also for palm oil mills. This is because the chloride that is reported to be responsible for the formation of the contaminant 3-MPCD esters in the refined palm oil appears to be a strong contender and one of its sources can be traced to the process water used in the mills. Acidity has also been proven as a precursor for the formation of the esters where higher level of the esters was formed
in acidic condition.