On July 23, 2019, the German consumer organization Stiftung Warentest published an article investigating the concentration of melamine that migrates into drinks from bamboo-based, re-useable cups. The organization carried out tests on twelve re-useable bamboo cups. Each cup was filled with 3% acetic acid and kept at 70 degrees Celsius for two hours to simulate contact with a hot drink such as coffee. This was repeated seven times for each cup. Measurements showed that four of the twelve cups resulted in ‘very high amounts of melamine’ (CAS 108-78-1) after the third filling. In three of the other cups, this occurred after the seventh filling. High concentrations of formaldehyde were also measured.
The article reminds readers that such bamboo cups cannot be made from bamboo alone and rely on the addition of melamine-formaldehyde resin to serve as a glue to hold the bamboo together. It warns specifically against the use of such cups in microwaves and also criticizes manufacturer claims advertising the recyclability and biodegradability of the cups. It explains that as the cups are made with melamine, they will neither degrade in the environment nor within industrial composting facilities for many years. The cups are also not recyclable in traditional material recycling processes. Only waste to energy incineration is an option.
Concerns about migration from bamboo food contact materials and also about marketing efforts labeling them as ‘eco-friendly’ were also published in a recent discussion document from an EU working group (FPF reported). The International Agency for Research on Cancer (IARC) has recently classified melamine as being “possibly carcinogenic to humans” (FPF reported).
Stiftung Warentest (July 23, 2019). “Bambusbecher im Test – Die meisten setzen hohe Mengen an Schadstoffen frei.” (in German)
EUWID Verpackung (August 12, 2019). “Bambusbecher in der Kritik.” (in German)