BigWallop ) gurgled happily, sounding much
like they were saying :

Old recycled sleepers are not really suitable for a garden where
people are sitting on them

They'd have a fence going straight up from the back, so not going to be the
most comfortable seat. "Perch", possibly, but not really seat.

or making use of them as flower bed
borders and veggie bed borders (if that's what you'd call them),

Mmm. Some of them were going to be for that.

But that was the old recycled sleepers which I think are
now illegal to sell to the general public for all those very reasons.

Unless all the various websites are w-a-a-a-a-y out of date, it would seem
they're still legal for sale. But obviously, they've got a vested interest
in playing down any health risks.

New sleepers are obtainable though, and these have not been given the
strong treatment that the older ones got. These can be used quite
safely for around the house uses. So you can have the newer ones
without worries.

Yes, but the newer ones aren't as thoroughly preserved, are some tatty
softwood, and just plain don't have the "look" of the old ones...

This site tells some more tales on them:
http://www.rdgservices.com/newsleepers.html

"Railways sleepers cannot be used in the following circumstances."
"Areas where there is the risk of prolonged human contact. i.e. Retaining
walls which people walk past all the time."

Mmmm. That's starting to sound likely.