Martyn said:
Cocobolo might be the best bet, but some people are strongly alergic to it...
A very important point, Martyn ... here's a good explanation of possible problems ...
"There is no doubt that some woods can be potentially toxic to some people. The question is always one of "what degree". This cannot truly be answered. Each individual has different degrees of resistance, some more prone to allergic reactions, and others not so. Every day our knowledge of tree biology and chemistry grows, leaving us with more information, but also more questions. How all this relates to each individual is impossible to know. All we can say is "be cautious". Use new woods in a limited way, with proper respirators, until you know that it has no adverse reaction with your body.
Toxicity can mean a lot of different things to different people so here are some basic ideas:
Natural Chemical Poisons:
This normally refers to chemicals produced by the tree. It has been suggested that these chemicals originated as part of the trees natural defense system against insect and other animal attack. They tend to be present in higher concentration in the sap, bark and foliage of the tree, and to a much lesser extent in the trunk. For example, the foliage of black cherry contains a precursor of cyanide, but yet we work with the wood with little difficulty.
Woods that are naturally oily, even after kiln drying are much more likely to cause an allergic reaction, just because the woods oil can transfer onto your skin more easily and enter the blood stream. The reaction can range from that of a mild irritant, to something that is truly toxic and lethal, although the latter is very rare."
My own opinion is stick with Cocobolo and give out rubber gloves to anyone in doubt
Mark