Many plants that are naturally resistant to mold, rot and insects are high in silicon content in proportion to carbon. Silicon is just not edible to most life-forms, so it makes sense this would work.

As important as the non-toxic nature of the product is the non-corrosive nature. Most other pressure treated woods are highly corrosive to all ordinary fastners except stainless steel. IF one can’t count on your fasters to endure as long as the wood, there is not much point in building w/ P.T. wood. This alone could make it worth the price and long lead time involved, but I hope they are considering expanding their operations soon, or licensing their processes to operations in other parts of the nation.