While I don't use balsa -- because yucca is so much safer and easier to get and cut into shapes -- like others, I wouldn't worry about toys made from reputable dealers. I have been collecting and posting stories on Birdsafe.com for over 10 years (and the site only contains a fraction of the stories I have received), and I have yet to hear of an issue with a balsa toy.
I am much more worried about many other toys that are on the market today -- toys that contain batteries (talking toys -- those could be deadly under the right circumstances), toys that attach to the side of the cage that spin, toys that contain long rope/leather strands that could wrap around a bird's neck, and many others that have been shown to be a problem with some birds. Not that I wouldn't even give some of those to my birds, if I feel they can safely play with them -- as I say -- any bird can find trouble with anything given the right circumstances.
But if my bird loves balsa toys and has been playing with them for years without issue, I wouldn't take them away
I am much more worried about many other toys that are on the market today -- toys that contain batteries (talking toys -- those could be deadly under the right circumstances), toys that attach to the side of the cage that spin, toys that contain long rope/leather strands that could wrap around a bird's neck, and many others that have been shown to be a problem with some birds. Not that I wouldn't even give some of those to my birds, if I feel they can safely play with them -- as I say -- any bird can find trouble with anything given the right circumstances.
But if my bird loves balsa toys and has been playing with them for years without issue, I wouldn't take them away