I also realize that many, if not most, wood workers do not have endangered species lists memorized, therefore I think it worthwhile and important to do even a small amount of research before purchasing any lumber, domestic as well as imported, to be certain of the potential impact you are having, even in a small way, on threatened or endangered populations. This information is easy to come by and takes only minutes to locate through any Internet search engine, including those you can access on your phone as you are standing in the lumber yard or store. Unfortunately, you simply cannot count on a vendor to tell you a product they are selling is endangered.
Health Hazards
Madrone is not known or documented to cause any specific negative health effects, but the long-term negative effects of exposure to sawdust of any species are well documented.
It is important to remember that although many people may, or may not, be sensitive to any given wood the only experience that truly counts is your own, so use reported side effects as guidance but not as a substitute for cautious and safe practices. After all, despite a lack of reported major health effects, turning a bowl blank of Timborana almost killed me through immediate respiratory distress followed by a multiple week long illness, so caution is ALWAYS warranted.
Appropriate protective equipment is therefore always recommended when working with this, or any other, wood, exotic or domestic, unless you have worked with the species before and are certain you are not sensitive to it.
But also bear in mind that many of the negative health effects, although certainly not all of them, are associated with high volume contact among industrial users working in mills and other processing facilities where the amount of contact with dust and wood is much higher than would ever be realistic for a hobbyist user.
Complete information about health hazards associated with a wide variety of exotic hardwoods is available from The Wood Database. Additional information about how to best use a dust collection system and personal protective equipment, such as respirators, can also be found through this excellent and comprehensive resource.
Fortunately, I experienced no negative side effects when working with Madrone.
My Personal Experiences
As is typically the case, I was only privileged to work with a very small piece of Madrone Burl so my experiences with the material are quite limited.
As reported by others, I found Madrone Burl to make an excellent and very dense turning material. The burl was well packed with curvy grain and burl-eyes which made it quite visually striking. I had no difficulty in achieving a fine turned and sanded finish with Madrone Burl and it accepted the application of a cyanoacrylate pen finish quite nicely as well.
Overall, I was very pleased with my albeit limited experience with Madrone Burl and I would be delighted to work with it again in the future, however I suspect that the very high prices commanded by larger bowl blank sized pieces will limited my experiences to the smaller, although still quite high end, pen blank sized pieces in the immediate future.
As always, I wish all my readers a great experience in whatever their wood working interests happen to be and to those who like working with lathes especially, do a good turn today!