At first glance, food and beverage containers made from bamboo seem like a good choice for environmentally friendly consumers. Bamboo is the fastest-growing plant on the planet, so there’s no shortage of sustainable material. Plus, bamboo containers are reusable and can, therefore, replace the disposable containers used by coffee shops and other food and beverage outlets.
According to data cited by German consumer organisation Stiftung Warentest foundation, disposable coffee cups create 40,000 metric tons of waste each year in Germany alone.
However, a recent test by the consumer group, that investigates and compares goods on the German market, has shown that by switching to a bamboo cup you might be risking your health in the process.
Testing 12 different bamboo cup brands, Stiftung Warentest found that buyers are generally given the impression that they are buying natural products. With descriptions such as “bamboo mug” or “made from bamboo fibres”; producers gloss over the fact that the cups are made from a powder of finely-ground bamboo fibres that are then glued together.
All of the cups tested contained melamine resin, a glue made from formaldehyde and melamine. Formaldehyde is a known irritant and is carcinogenic if inhaled. Melamine is suspected of causing damage to the bladder and kidneys.
As reported by Food Packaging Forum, the International Agency for Research on Cancer has also recently classified melamine as being “possibly carcinogenic to humans”. Still, as long as certain conditions are met, melamine resin is not considered a dangerous substance.
Bamboo cups not suitable for hot drinks
One of these conditions, however, is that it is kept under 70°C, and these bamboo cups are being specifically marketed for hot drinks. So, when the Stiftung Warentest testers simulated the process of adding a hot drink to the cups, they made a concerning discovery.
The test is outlined in the video below (don’t forget to select the correct subtitles if you don’t speak German):
The cups were filled with 3% acetic acid and kept at 70°C for two hours to simulate contact with a hot, slightly acidic drink such as coffee. This was repeated seven times for each cup. After the third and seventh fillings, the liquid in each cup was tested for chemicals.
The results showed that four of the twelve cups contained “very high amounts of melamine” after the third filling. In three of the other cups, this occurred after the seventh filling. High concentrations of formaldehyde were also measured.
Even more concerning, the results were sometimes higher after the seventh test, suggesting that the harmful chemicals don’t evaporate but continue to seep into drinks with prolonged use.
Keep bamboo cups out of the microwave
Stiftung Warentest also slammed the manufacturers for not properly warning about the dangers of placing the bamboo cups in the microwave. When heated to high temperatures, the cup’s material will begin to decompose: as the cup’s surface is destroyed, it will release even more melamine and formaldehyde. One cup’s packaging simply stated that it should be kept out of the microwave to prolong its life.
Many of the cups also suggested that they were “biodegradable” or “recyclable”. Stiftung Warentest maintains that this is a barefaced lie. Of course, natural bamboo fibres will biodegrade over time, but the cups will not rot, even if you give them years. Neither can they be recycled via standard methods—the only option is to burn them.
Their overall advice? “Keep your hands away from bamboo cups,” the Stiftung Warentest report concluded. “Use reusable cups made of materials other than bamboo.”
Featured image: Screenshot from video