Pack Analysis showed that the problem can contains high content of nitrate on problem can; where the problem can is 55% higher than the normal can in nitrate content. Nitrates in the packed can acts as a depolarizer. Normally chrome on the TFS becomes the sacrificial anode and retards further corrosion of the substrate. But with the presence of high content of Nitrate acting as depolarizer, chrome +++ cannot protect substrate thus making the iron becoming the sacrificial anode resulting to pitting. Hence, pack variation could be a probable cause of the problem