k, called GE and talked with them about this. It contains NOTHING in the way of additivies. NO mildewicides, nothing of that sort. The reason they state "not for" is due to what I expected, the shear strength and its ability to keep a super strong seal forever. Which is fine. I'll reinforce it with some other stuff, but it won't leach anything toxic in once it's cured.
So there we go. Good to know. Now, how long it'll hold up is another question, I don't figure I'll keep this sump design for more than a few years, so if it'll do that - I'm set.
Now, to finish the egg crate stand with the garden material cover
