Environmental hazards of asphalt shingles?
I have a stack of them (I think that's the right name -- the gritty, flexible ones that come 3 to a sheet and you nail them on, overlapping?) left over from roofing the hen house.
I'm thinking of using them as edging for the vegetable patch where the weeds pop up under the fence. But I'm concerned about any potential hazards as they degrade into my soil.
Any information? A quick Google search was mostly fruitless.