Safety Sign Blindness
Recently I was asked why there weren't signs up to highlight a hazard that had recently contributed to an injury. The comment brought back a discussion I'd had more than 10 years earlier with an Offshore Installation Manager (OIM) who'd suggested that we put some signage up to warn people of a hazard he'd observed. On the face of it, it sounded a reasonable request, but I took the opportunity to challenge him to personally recall what signage was on the rig's galley door - a door that he opened at least 3 times a day for more than 6 years and a sign you'd expect him to know. As yo guessed, after some thinking and some blank stares, he laughed at me and said he had absolutely no idea (it said 'Fire Door', by the way, which is pretty important to know if you're responsible for offshore safety). So the question is, are more safety signs always the solution? Let's consider some research into the topic.
Cluster Sign Blindness
Cluster sign blindness is term used to describe the phenomenon where employees are more likely to disregard the less 'visible' signs within a cluster of signs. There will be a tendency for individuals to only focus on those that are larger, brighter or placed in their eye-line and for them to disregard signs with fonts that are too small, aren't engaging in their design, color or impact, that are either too high or low, or that (based usually on gut instinct) seem irrelevant.
Unfortunately, the most common location you'll see 'cluster' signage is at the entrances to hazardous work areas or in high-traffic locations. In my experience, this is because there is still a mindset within company HSE teams that they need to meet regulatory requirements for advising employees of various rules and regulations and the simplest solution to meet their obligation to 'inform' is by putting signage in the high foot-traffic areas such as the site entrance or the control room, the office printer room or coffee shop. This signage isn't necessarily about mitigating a hazard or keeping employees safe, it's about employers being able to say "we told them so". As you probably guessed, this isn't necessarily beneficial to those that are going to be exposed to a hazard.
Familiarity Sign Blindness
This phenomenon occurs when employees become so familiar with their workplace, they begin to disregard information such as the signage. They might have originally paid attention when it was first put up, or when they were new to the workplace, but over time the awareness dissipates. This particular situation is expressed as 'familiarity sign blindness' and was what happened to my OIM.
Employees unconsciously filter out irrelevant information for the information that they need in the present. The science indicates that this has to do with the way our brains process the enormous amount of information we're exposed to on a daily basis.
Research indicates that there are approximately 40,000,000 sensory inputs per second being registered by our brains, and our conscious brains are only able to process approximately 0.02% of these. Obviously, there's always going to be a risk that an important safety message will be lost in the ether, disregarded by the super-computer that is our subconscious as irrelevant. Interestingly the subconscious part of the brain (doing the processing) is 5000 times faster than our conscious, so it doesn't just disregard it - it tosses it out real fast.
If a situation or environment is 'normal' and not a threat - which is 99% of the work day for most of us - and signage doesn't relate to our current activity and we consider that the brain is working independently to disregard vast sums of sensory information so that the brain's resources can focus on what it considers as the 'important' things, it's easy to see where we're not going to pay attention.
Some Suggestions for Signage
The message is simple - keep the relevant, keep it simple, make it visible, focus on safety and risk reduction and not just regulations.
With this in mind, some practical suggestions are to;
Keep the signs that matter - convince yourself "Do we really need this?", if not lose it
Keep signs clear, concise, clean and visually appealing
Check the regulations (particularly for such 'important' signage such as exit, fire equipment signage)
Cluster similar signs together (i.e. use a single sign for hardhat, hearing protection, boots etc.)
Place signs where they are most relevant - not most convenient
Place signage in the eye-line of the worker being exposed to the hazard
Prioritize your signage, consider the 'Danger', 'Warning', 'Caution' model
Use standardized signs that the employee is familiar with (ISO 3864)
Understand that symbols assist recall
Use other methods to reinforce the messages/risks to the workforce that necessitated the signage in the first place - toolbox meetings, inductions, training, newsletters etc.