as i understand it a safety factor of 1 would be a minimum for glass thickness as to size of panes
so when full of water it might handle the odd light tap or knock
i have used a safety factor of 3 for our tanks as they are on public display
which i hope means they should be able to handle 3x the impact or 3 x safer than the minimom requirement
that said i don't think any tank that is full will stand a good whack with a hard, pointed object
this is just my opinion