From Cranky Yankee's post above

"....."To my knowledge, except for Honduras mahogany, no wood used in musical instrument construction is toxic......."
"Toxic" is a misleading and emotive word to use in this context. Literally it means poisonous, and Honduras mahogany is not poisonous. It can occasionally (as can any wood) cause an allergenic reaction , but not nearly as much as rosewood does. Some people can be affected, most people will not experience any ill effects.

Cocobolo, which is a very popular wood in high-end custom guitars, is notorious for the allergenic reactions caused by its sanding dust.

I am fortunate so far in not having experienced a reaction to anything except MDF dust ...

Murray