In the typical modern factory, signs are everywhere. While the intention is good, the effect can be counterproductive. People get "sign fatigue" and start tuning out the flood of messages. In some facilities, there are so many signs overhead, on the walls, and on equipment that they blend into each other and ratchet up the background noise.
Reserve sign usage for important messages. When signs become too abundant, people start ignoring all of them.
People may disregard a particular sign because they believe the information is outdated or incorrect. If you think a safety sign is outdated or incorrect, tell your supervisor and ask to be notified of the resolution.
Outdated signage can be a lethal problem in applications covered by NFPA 70E. Don’t assume the original sign reflects current conditions. When working around energized equipment, use the sign as a starting point rather than a substitute for hazard analysis.
A final note: Don’t assume a danger doesn’t exist just because a corresponding sign isn’t there.