A reference material for the determination of overall migration from a plastic coextrudate into the fatty food simulant olive oil was produced and certified in an interlaboratory study. The analyses were carried out according to the ENV 1186 standard from the European Committee for Standardization (CEN) [1, 2, 3] with exposure of the coextrudate to olive oil for 10 days at 40 degrees C. After an initial preliminary interlaboratory study eight laboratories participated in the certification round, and two different methods were used to obtain single sided exposure of the plastic to the oil. The certified value was determined as the mean of laboratory mean values. No outliers were found. A reference value of 8.6 mg/dm(2) +/- 1.4 mg/dm(2) (+/- half width of the 95% confidence interval) was obtained which is within the range relevant for the regulatory limit (10 mg/dm(2)), making this reference material suitable for laboratories measuring according to the EU overall migration limit . The material has been found stable over 45 months.