round up you can buy from diy stores is not the same as round up from an agrichemical distributer, as already stated to apply many of the agrichemicals a licence is required, a proficiency test has to be obtained, the operater should wear protective clothing and appropiate masks depending on product a record of amount purchased, where stored , where applied etc etc. I did a number of years ago work as a crop spray operator working with every kind of chemical imaginable .most now banned completly cccp, been one of them, by far the most dangerous were infact the pesticides.
We did infact use to have a mixture of cccp and deisel sprayed by helicopter to control thye growth of bracken, this worked wonders on any thing but round up is basicly safe and its effect is good if applied correctly because it is systemic , killing the weeds at its source , the roots although this can take upto a fortnight, for instant results gramoxone is the one but weeds will return.
geoff