Safety procedures, safety talks, signs and other instructions direct workers. But attempting to identify all behaviors needed to keep employees safe fail in the midst of a changing work environment of aging equipment, cost-cutting, and changes in processes and people.
We also get complacent around these practices.
However, when peers are observing and giving feedback they are constantly looking for new hazards and at-risk behaviors, even those not listed in policy manuals, and having conversations about threats to safety.
Yes, direct the behavior you want to see; this is necessary but far from sufficient.