In an article and TV report published on May 22, 2017 by the German TV station NDR, journalist Heike Dittmers reported on the inner plastic coating of coffee to go cups. Dittmers collected samples of coffee to go cups from McDonald’s, Tchibo, Starbucks, von Allwörden, and an unspecified canteen, and sent them to a certified laboratory for chemical analysis of the coatings. In three cups (canteen, Starbucks, McDonald’s) the plasticizer diisodecyl phthalate (DIDP, CAS 26761-40-0) was measured at 0.03 mg/kg, 0.06 mg/kg, and 0.10 mg/kg, respectively. In two cups (McDonald’s, von Allwörden) a mix of hydrocarbons was measured at 0.41 mg/kg and 4.86 mg/kg, respectively.
According to Dr. Jane Muncke from the Food Packaging Forum, chemicals from the coating can migrate into hot (and particularly into fatty) drinks such as coffee (e.g. with milk). The legal migration limit for DIDP is 9.5 mg/kg. However, Dr. Muncke highlights that phthalates are suspected endocrine disrupting chemicals (EDCs) and people are exposed to these substances not only from coffee to go, but also from other food and drink products contaminated with phthalates by the packaging or during production processes. Regarding the mix of hydrocarbons, Dr. Muncke suspects that the detected long-chain hydrocarbons could accumulate in body fat.
Heike Dittmers (May 22, 2017). “Kaffeebecher: Was steckt in der Beschichtung?” NDR (in German)