ItnawitaAwaluddin, AmirSyahrul, JhonAnita, SofiaMerlinda2014-05-212014-05-212014-05-21978-602-18936-0-9wahyu sari yenihttp://repository.unri.ac.id/xmlui/handle/123456789/6273Yogurt is popular dairy milk. It is usually packaged by HPDE or PET plastics because of simplicity. However, it has disadvantage that is migration of monomer such as carbonyl compound (formaldehyde or acetaldehyde) during stored. The mechanism of migration is accelerated by microorganism activities and acid content during stored in refrigerator. Method used in this research was UV-Vis Spectrometry using Schiff’s reagent. The result showed that during stored, the concentration of formaldehyde in samples increased after 20 days of HPDE and 60 days of PET. It was found that the highest concentration of formaldehyde after 70 days stored was 3.250 mg/L of HDPE and 1.488 mg/L. Based on ICPS, UN (ILO, UNEP and WHO), the concentration limit of formaldehyde in food is 1 mg/L. It concluded that yogurt packaged by HDPE and PET is not safe after 70 days storedenMigrationFormaldehydeHDPEPETUR-Proceedings