Unfortunately, the same rules that banned old style creosote also
banned creosote and tar covered sleepers coming into contact with soil.
The risk is apparently one of phenolics geting into the soil. The
legislation is not retrospective, if there are there than that is ok,
but not going forward. When sold a tar / creosote covered sleeper, you
should be asked and sign to say that you are not putting them on soil,
thoug what else you would do with them I know not.
Clifford
Bawtry, Doncaster, South Yorkshire