I don't know that the toxins will kill all plants, many people use them for raised planters for flowers, I'm just not sure I would want to eat anything grown in them. The chemicals used to treat them do leach slowly over time, I guess you will just have to make a judgement for yourself as to whether you want to continue to use them or replace them.

why not try asking the wood supplier if its a problem?

when you bie treated wood, it is usualy tanalised, it dose in a short time leach out but it is the sun that dose the leaching, if you look at it after a while when what you can see has faded, lift it and you will see that the part that was int the soil has not leached half as much , it is harmless, they say a little lerning is a dangerios thing,your nabour is geting it mixed up with crearsote, if it is green or light brown you are proberly looking at tanalising, the industry moved away from creasult years a go and the only way you will get it on wood is if you put it there yourself,

Most new treated wood today is treated with plant and (I hope) human friendly chemicals, so leaching and contamination should only be a small problem. Unless you are prepared to replace the timber every couple of years, there really is no alternative to using treated timber.
The real 'nasties' are things like old sleepers which have been drenched in creosote which is a know carcinogen. But even with those, as long as you harvested vegetables away from near the edges I suspect the amount of contamination of the soil would be minimal.

I agree with Bertie, You should be fine. I would imagine that anything toxic enough to harm humans would kill the plants first!

I wouldnt worry about this. The treated wood unless its old engine oil/ tar/ creosote wont be a problem to your plants.

What was the wood treated with?

thanks, i am reassured now.