Re: Building a large spire out of blocks of eggcrate, what to do about the sides?
Encyclia brings up a good point to consider. I have a few thoughts:
1) The studies concern styrene monomers and trimers - not the long chain polystyrenes of which styrofoam is built. Polystyrene is non-biodegradable but it can be degraded by sunlight. Even sunlight degradation, however, leads to small bits of polystyrene - not styrene itself. I think the concern over styrenes are more an issue of pollution from plastic manufacture rather than a problem with polystyrene itself. I will admit, however, that I have not found what I would consider to be "hard evidence" one way or the other.
2) Many things are made of polystyrene - including egg crate. Unless you are going with an all-natural materials viv (+ silicone and glass of course!), you may not be able to avoid polystyrene and concerns about leachates from plastics generally.
I feel a bit like someone telling a pregnant woman that smoking one cigarette isn't going to hurt her baby: A single cigarette won't hurt her baby, it's true - but what will she think of me if she her baby is born with a a birth defect after she has that one cigarette?