Signs are not a substitute for safety. They aren’t band aids that cover hazards that were best eliminated in the first place. Signs are a warning, not a substitute for proper machine safeguarding.
With all signs, the goal is to state all important information clearly and unambiguously. To do this, it requires being 100% sure that the words, pictures, numbers, diagrams, schematics, codes, and symbols on the sign are easy to understand for everyone who may come into contact with them.
A warning needs to be clear without having to consult another person to clarify. Designing a sign to be legible from the start must be a priority. However, humans aren’t perfect, and if a mistake makes it to print, employees need to be aware that they have the right to contact the relevant personnel to clarify the meaning of any sign.
The hazards that exist for a site should be apparent from the warning. Not only does the reader need to be aware that there is a hazard, but they need to see what it is and why it’s dangerous. Knowing why will ensure that employees will have the capacity to navigate their own way around the hazard and take it seriously.
Employees need to have no doubt about what the hazard is or why it’s dangerous. A common example of this is a no-smoking sign. Just stating that an area is not somewhere that smoking can occur isn’t enough information. The sign needs more information to be complete. Even adding wording like vapor ignition isn’t optimal. To make it abundantly clear, stating that explosions are possible should be part of the warning.
Working in the field, I remember a good example of this. A team was working in a permit-required space. They were working next to a pipe that stated, “WARNING: ARGON PURGE.” The warning was specific enough as to what the hazard was but it failed to display the consequences of it.
Argon is an inert gas itself and isn’t harmful on its own. However, too much argon into an enclosed space will displace all of the oxygen in this area. There is no guarantee that every employee that looks at the sign will immediately realize the risk of the oxygen deprivation that the sign implies. This gap in communication may seem small but can become tragic. That hazard ended up taking someone’s life.
There is a preferred order for displaying multiple pieces of information on a sign. We’ve been conditioned since we were kids to read from top to bottom, from left to right. That is the orientation to prioritize. Signs shouldn’t take time to mentally process.
The color of the sign needs to stand in stark contrast with the surroundings. The color of the wall it’s posted on needs to be considered as well. The placement of the sign should still allow for it to be readable and understandable.
When there are multiple lines, it is recommended to justify them. Centering or right-justifying the text is not recommended. Following this standard pattern makes it easier to interpret the sign:
Carefully consider how easy a sign is to read and how quickly the message is understood. When there are several parts to the sign, this becomes even more important. The header needs to be in all uppercase letters. After that, using a mix of upper and lower case is the rule to follow. A key to clarity is to keep important clusters of words together on the same line so that misinterpretation can be avoided.
One of the few exceptions could be the standard “NO SMOKING,” sign. With only one message spread across two words, the sign can get away with splitting the words up into two lines. As long as the “NO” is obvious on the top line and the “SMOKING” is immediately under it to keep it clear that they are linked, then the message can still be cohesive.
If the warning to not smoke was part of a larger sentence, then separating the “no” and the “smoking” onto different lines would not be acceptable.
Exit signs are some of the most common signs and the most important to get right. Experts have chimed in countless times on this subject because it is so fundamental to so many emergency situations. Inadequate signage in an emergency is inexcusable, but by the time that happens, it’s too late.
A common error in placing exit signs is against the back walls at supermarkets, warehouses, or large industrial spaces. The placement seems fine because when it’s being placed the observer is looking right at it. If they go even a few feet to the side, the sign will now be difficult to see. Not only exit signs but extinguishers will often share this fate. The problem is exacerbated by having a rack in the way or placing the extinguisher in a recession.
Not only do exits need to be marked but also non-exits need to be clearly identified. Signs stating “NOT AN EXIT”, “SUPPLY CLOSET,” or “BOILER ROOM,” are important. If the door could be mistaken for an exit, it needs to be marked. Evacuees need to know where to avoid false exits and hazardous spaces during an emergency.
Glow-in-the-dark signs are excellent supplements to existing signage. Using signs, arrows, and strips can guide people out of a building, even under a smokescreen. Doors and frames need to be identified, as well as obstacles like bars, knobs, levers, paths, steps, landings, and handrails. Other places with restricted movement need to be clearly marked like restricted height areas, standpipes, and hose cabinets.
Doors work best when they have duplicate signage. Having a second sign above the door makes it easy to identify even when the door is open. If a door is left at an angle, the sign is easily obstructed and might not be in someone’s line of sight until they already pass it.
Doors that open more than 90 degrees can obfuscate a single sign completely. The problem is worse if the door is opened towards the observer, with the sign now completely behind the door.
Evacuees could waste valuable time looking for an exit if it’s not properly marked. They could head for an exit that is farther away if the closest one is not clear. They could wander into the wrong area, one which traps them or exposes them to more hazards than before.
Signs need to be available at all times because they are there to warn about particular hazards. They don’t always indicate an exit, but provide other warnings or inform those entering the space what personal protective equipment is required.
The posting needs to be durable enough to withstand the environment it’s in. If a sign is vulnerable to chemicals, swings in temperatures, or adverse weather conditions, its service life won’t be as long. Whenever exposure to a harsh environment is possible, the signage needs to be prepared for it. Waterproof materials might be called for, paper may need to be laminated to be sure that the message remains legible.
Evacuation floor plans come with their own set of rules. The important thing to keep in mind is keeping the diagram neat, clear, and organized. The reader needs simple symbols with contrasting colors to show important points like exits, extinguishers, and manual alarms. One of the most important symbols to get right is the YOU ARE HERE designation. They need to quickly know exactly where they are so that they can get to their desired destination in time.
Plans need to be thought out ahead of time. They should be mounted in the correct orientation so that the reader can read their position and go off it without translation to the existing structure. This is one of the easiest details to miss, but in an emergency, it’s one of the most important things to get right.
Floor plans and safety signs are an essential part of any safety program. However, even if every sign is perfectly designed, printed, and posted, it still isn’t a substitute for employee knowledge or other safety equipment like extinguishers, lockout tagout, and manual alarm signs. That’s why proper training is paramount. An evacuation plan that has been practiced is the one that will succeed.