Bamboo grows fast, so it's sustainable, it requires few pesticides, and the plant has some natural anti-microbial properties, too. The plant itself is actually very eco-friendly. The problem lies with the processing and labeling of some bamboo fabrics used in baby clothes, crib bedding, and more.
According to the U.S. Federal Trade Commission (FTC), much of the bamboo fabric in baby products is actually rayon, which is decidedly less eco-friendly. When the bamboo fibers are made into rayon, a lot of chemicals are required, which release toxins into the environment. There's not much of the original plant fiber left by the time the processing is finished, and the anti-microbial features are often lost. It also may not be bio-degradable as some manufacturers have claimed. You end up with a synthetic fabric that is labeled as natural and organic bamboo.
The FTC says, "most 'bamboo' textile products, if not all, really are rayon, which typically is made using environmentally toxic chemicals in a process that emits hazardous pollutants into the air. While different plants, including bamboo, can be used as a source material to create rayon, there’s no trace of the original plant in the finished rayon product."
Companies are supposed to label this type of fabric appropriately. It should not be called "bamboo" unless it is made directly from the fibers. It should otherwise be called "rayon from bamboo" or "viscose from bamboo." The FTC has recently cracked down on some companies that improperly labeled their products as bamboo.
Of course, there are two sides to every story, and bamboo products manufacturers certainly have their own story to tell. Many say that rayon from bamboo is nothing like traditional rayon. All of them tout bamboo's eco-friendly properties. I have yet to see any information supporting the eco-friendliness of the actual manufacturing process and the chemicals used in that process, though.
If you're buying bamboo baby products, you'll need to do a little extra research to make sure you're getting what you want. Bamboo baby products made from the actual bamboo fibers or the wood itself likely are eco-friendly. For bamboo fabrics, the FTC says manufacturers should have testing data and fabric analyses on-hand to prove that their baby products are, indeed, made from natural bamboo instead of heavily processed fibers.
Not all bamboo baby products are heavily processed in a way that would negate the eco-friendly label. Plenty of manufacturers use bamboo in an environmentally responsible way. It's just a good idea to double check that you're buying a product that truly matches your desired level of green.