TLDR

Most of the mugs that are being sold as made of "bamboo" these days are actually plastic with some ground-up bamboo mixed in. They are not more biodegradable, or healthier, but they can still be a good choice as a sustainable way to drink your coffee.

Bamboo

I've been seeing more and more posts on Instagram about bamboo travel mugs and cups. There's clearly some confusion surrounding these products, so I thought I'd write a little about them.

Bamboo has been popular for decades as a sustainable base material for anything from kitchen floors to bicycle frames. It’s a beautiful material in its natural state, but few of the uses we see leave it that way. Many of its applications require the raw bamboo to be processed in some not-so-good-for-the-environment ways. The impact of this processing is generally not taken into consideration, and my take is that bamboo’s touted advantages are a lot more marketing hype than actual environmental benefit.

CUPS, MUGS AND BAMBOOZLEMENT

In the case of “bamboo” coffee cups we suspect something is fishy already when we look at the product. Does it look like bamboo? It sure doesn't. It looks like plastic. And it is in fact mostly plastic. What is sold as “bamboo” is called in the industry filled plastic, i.e. plastic resin with some filler powder or fiber mixed in. In this case the filler is ground bamboo:

resin + bamboo powder = cups

Fillers have long been added to plastics to modify the base polymer's performance somehow, or to make a less-expensive product by using a filler that is cheaper than the resin. Bamboo powder probably adds some stiffness to a molded cup and makes it cheaper to produce.

The big benefit of adding bamboo to the resin used to make cups though is a marketing one: consumers think they are buying a more earth-friendly, healthier product. In the marketing messages on the packaging there is generally no mention of the plastic content (or the type of plastic resin), and the cups are claimed to be eco-friendly and biodegradable. They are, in fact, neither.

SUSTAINABILITY

tableware of bamboo-filled plastic

That is not to say that these are bad products. I have been testing some small bowls made of a bamboo-filled resin in the Joeveo corporate dishwasher since October, 2014. Four years and maybe 500 dishwasher cycles later they still look good. I like the feel of their slightly rough surface (though some might prefer a smoother surface for thorougher cleaning).

And what about sustainability? Well, if you frequent coffee shops, these cups, like other reusable cups and mugs, are much better for the planet than the single-use coated-paper cups that coffee is typically served in there. These plastic/bamboo cups have the potential to last a lifetime and beyond so that the energy and resources embodied in them when they were made and transported to you isn’t sent to the landfill and wasted.

THE BOTTOM LINE

If you like the looks and feel and price of that “bamboo” coffee cup you see on the shelf, or on your screen, go for it. Take care of it and enjoy it forever and you’ll be doing the planet a favor. But don’t buy it because it’s made of bamboo or because it’s healthier, or more sustainable, or more biodegradable than the same product without the bamboo. It isn’t!