Sealing H4 treated pine from leaching chemicals?

[FenceFurniture]

Currently there is a vege garden being built here.
http://www.woodworkforums.com/f286/vege-garden-built-208324

The posts and sleepers are H4 rough sawn Treated Pine. I don't fancy the idea of the Copper Chromium Arsenate leaching into the soil for edible plants to soak up, and I was thinking to paint the surfaces in contact with the soil with plastic paint (Solaguard). Thinking very seriously of painting the external faces of the sleepers with this paint anyway.

Is this the best way to seal in the CCA or is there a better product to use? I suppose I could line the inside with Builders plastic but that will pose logistical problems, in that the top part that is exposed to the sun will break down within about 6 months.

Should I perhaps do both - paint them and then tack the plastic on so that it doesn't go above mulch height and get exposed to UV? I could run an untreated batten across the top edge of the plastic to hold it it place. These battens would be sacrificial due to rot and simply replaced when required.

[NCArcher]

I wouldn't bother.

Can the arsenic leach from the timberinto my vegetable patch?
Arsenic may leach from treated timber into soil,although this is variable depending on a number offactors and is generally contained to the immediatearea surrounding the wood. Uptake of arsenic byplants is generally limited due to the distance fromthe source, the low amount in the soil and limiteduptake by vegetables generally.A review conducted by the APVMA concluded thatthe affected zone of soil is very limited and plantsgrowing near CCA treated posts did not haveelevated levels of arsenic
http://www.public.health.wa.gov.au/cproot/2278/2/copper%20chrome%20arsenate.pdf

[FenceFurniture]

Excellent! That article is just what I needed to read. Thanks very much Tony.

[justonething]

You can use paint that is bitumen based, they have strong adhesive capability when it is not in direct sunlight. Latex paint unfortunately does not stick all that well once dry due to the seasonal movement of timber and therefore should not be used.