The original intention of safety slogans was to remind people about safety. Unfortunately, the typical slogan generalizes instead of informs. There’s no actionable message. As signs proliferate, management often gets a false sense of security. Consequently, safety training wanes. That is, the slogans tend to substitute for substantive training. And slogans everywhere leads to worker perception that safety is already taken care of.
This is not to say that safety slogans are necessarily unhelpful. But they should help “flavor” the safety message instead of dominate it — the same way a little hot sauce should flavor an omelet. A little hot sauce makes for a great omelet, but too much ruins it.
It’s not that you need better slogans or more detailed ones. The question of more or fewer is probably not that important either. You need to assess how much actionable safety information workers are receiving, and make sure the use of slogans is proportionate to that. Just like putting a little hot sauce on an omelet.