old deck material to make raised veg beds

[devidmike]

I keep hearing its good to use this or that for raised gardens. since its always good to reuse and recycle. how safe would it be to use old decking lumber to build the side walls? We have a small deck by an above ground pool, unfortunately time was made it very unstable and we have no choice to tear it down. the wood is grey and is 5 to 8 years old. and the perfect length already. Think that's long enough for chemicals to leach out already? the wood has a little give but I can reinforce. I figure that's the cheapest way we can do it to be ready for next years planting. what you think.. good or bad idea?