1
general::
Phrase(s): on the safe side
Fig. taking the risk-free path. • Let’s be on the safe side and call first. • I think you should stay on the safe side and call the doctor about this fever.
McGrawhill's American Idioms And Phrasal Verbs
2
general::
Avoiding danger, with a margin for error, as in Just to be on the safe side, let's order another hundred chairs. This idiom was first recorded in 1811.
American Heritage Idioms