'organic' compost ??

I wonder if anyone has any experience/knowledge of Hills 'Warrior' compost, as sold here in Wilts., as I wish to create a raised vegetable garden and want it to be as organic as possible. Surely municipal green waste from local tips cannot be guaranteed to be chemical free, despite the literature stating that their product complies with BSI PAS 100 2005 Soil Assn. Standard? Or am I just being paranoid? The price is good @£53.50/1000 litres and delivered in handy cubic metre bags, but I am worried about residuals since reading article in issue 42 (sept '11) of 'Home Farmer' (pp25), which talked about, among other things, the recently re-approved-for-uk-use of herbicides clopyralid and aminopyralid (present in agricultural and domestic weedkillers). If there is a problem, can we trust any suppliers, apart from one's own garden? Thoughts, anyone? Thx in anticipation...