[Greenbuilding] Alternatives to Pressure Treated Wood

[dantonioli at earthlink.net]

I'm considering a roofdeck project where I'll have to use a lot of pressure
treated wood as "sleepers." The surface is uneven and there's only a few
inches of clearance between the bottom of the deck boards and the
roofdeck....which means a lot of long rips through pressure treated wood,
and a lot of copper green over all of the exposed untreated surfaces. The
last time I built a deck this way I told myself that I wouldn't do it again
because working with PT this way is unhealthy--there's a ton of pt dust, too
much copper green, and I can feel the physical effects and it sucks. I'm
most likely going to turn the job down but thought I'd look into options.
 
The question is: is there a rot resitant, structurally sound material that
can be cut and tapered? FSC wood? Exciting new composition lumber? 
 
Dan Antonioli