I live in the stuff (cocobolo), day-in and day-out. 'Thank the creator' I don't react to it. Probably about 5% of the guys who walk into my shop have related to me that they have had a reaction from it at one time or another. Another 25% or so are concerned about it because of what they have previously heard about it. I had one guy work for me that, as time went on, couldn't work around it any longer as the reaction got progressively worse.
I have around 12k board feet of cocobolo and mill it almost every day. Cocobolo stretches a full spectrum of colors, from almost ebony-like dark to lightish-tans, with reds, purples, oranges and all shades of browns in between. Every once in a great while, usually when cutting the real dark stuff (ebony-like dark and oily stuff), I get a burning sensation right up in my sinuses. As soon as I get away from it or put my dust mask (back on), it usually goes away, but that's just me and again I thank my 'lucky stars' it's nothing worse, otherwise I'd be out of business.
Sierra Madre Sawing and Milling
Sierra Madre, California