My suggestions:
- Situate the tanks in the lowest traffic area possible.
- Make sure that there is no way that the tank can be tipped over. Epoxy a bracket(s) on the back and attach it to the wall.
- If there is a stand with a cabinet containing plumbing (a skimmer in a sump, etc.), make sure that the cabinet locks.
- Cover as much of the top of the tank as is possible.
- Ensure that you have a drip loop and a surge protector. Bundle all cords together and affix them to the wall & tank stand.
- Keep all chemicals under lock and key.
There may be OSHA guidelines that dictate more, but I can't speak to them with any authority.