A no entry sign

Briefing: ‘Sign blindness’ - a significant risk to health and safety

Safety signs are a powerful way to ‘nudge’ people into adopting the right behaviours, so why then do people sometimes break the rules? asks Cheryl Peacock, editor of a new report by Seton. In this briefing, we investigate the concept of ‘sign blindness’ and the important impact it can have on health and safety.

Says Peacock:

“Leaving aside those who deliberately choose to ignore signage, one of the most common reasons [people break the rules] is ‘sign blindness’ – an industry term which simply means we fail to notice what’s in front of us. Sign blindness is a big risk to health and safety – but there are steps you can take to make sure potentially life-saving messages are taken in and understood.”

The HSE has brought a number of high-profile prosecutions against companies where poor signage was a factor in a major incident. The new report provides the following example: 

A company that manufactures metal pressings and sub-assemblies for the automotive industry was fined more than £500,000 in 2018 after a worker was struck by a forklift truck and suffered a serious brain injury. An HSE investigation identified inadequate control of workplace transport risks, including insufficient safety signage to highlight hazards.

Repeated exposure
Safety signage can be broken down into mandatory (e.g. wear high-vis), prohibitive (avoid a hazardous area), safeguarding (to prevent harm to others) and warning (take action now). A triangle is used to indicate warning, a square is normally for safety information and a red circle prohibits action, while a blue circle provides mandatory information, such as an instruction to wear PPE.

But, says Seton, as powerful as these signs are when we encounter them for the first time, repeated exposure over time can make them less effective. In other words, we become ‘blind’ to them, sometimes failing to register the hazard because we’ve not had an accident up to now.

As well as familiarity, signs can lose their impact when there are too many in one place – which is known as ‘cluster blindness’. When we’re confronted with so much information, it’s difficult to assess the level of risk quickly. 

Says psychologist Dr Jennifer Parkin:

“As we go about our day to day lives, we may think our visual perception captures the world around us in a camera-like way, such that we perceive every detail that hits our retinas. But research evidence indicates that this just isn’t the case. There are limits to the amount of information that we can pay attention to at any one time, and so we actually only perceive some of the visual information presented to us. If we’re focusing on a specific task, we are less likely to notice an unexpected object even if it falls within our gaze – a phenomenon called inattentional blindness.

“Perhaps unsurprisingly, our brains seem to be primed to pick out and focus on things that are relevant to us – we’re less likely to experience inattentional blindness to our own name than for other words. We’re also more likely to notice faces than objects if they occur unexpectedly in a scene.”

Dr Parkin continues: 

“Change blindness is another example of how we can be looking at something, and yet fail to notice key elements. It’s a well-documented phenomenon whereby if an object or scene that we’re deliberately paying attention to changes while we’re looking at it, we don’t actually detect that a change has occurred. Interestingly, we tend to underestimate our susceptibility to this. Even people who consider themselves to be observant – the kind who pick up on continuity errors in films – still experience change blindness. It doesn’t just happen with subtle details, like changing the font of text, we can also miss much larger changes, such as switches in conversational partner in a one-to-one interaction.”

The report advises that, when an environment is cluttered with signs, we find it difficult to pick out the information we need. Even if we know the signs are important and relevant to us, if there are too many of them, we are less able to take on and respond to the information presented in those signs. Feeling overloaded with information causes a stress-response, which in turn can affect cognition and behaviour. If we’re trying to navigate within a building, and the signage is complex and cluttered, we are more likely to just ignore all the signage and find our way somehow else, such as asking for directions.

Improving the effectiveness of signs
There are ways to increase the likelihood that signs will be noticed and heeded. Seton advises that ensuring that they are well-positioned (in the sight line of the intended viewer) and readily legible at the distance they will be encountered are obvious fundamentals. Limiting the information – both in terms of the number of different signs, and the information given within any one sign – is also important. If lots of information does need to be conveyed at a particular location, using a hierarchical layout helps the reader pick out what they need.

Seton says using other modalities to draw attention can also be helpful – auditory alarms and sirens are particularly effective in signalling there is a hazard. Flashing lights also increase the likelihood a hazard warning is noticed. It must be remembered however, that all stimuli, regardless of mode, add to our cognitive load. If alarms sound too frequently, they have a detrimental effect on cognition, increasing the likelihood of making a mistake, as well as causing stress and fatigue.

Says Ed Barnes, Product Innovation Manager at Seton:

“All safety signs say something important – the problem is that they eventually start to feel like part of the wallpaper when people see them every day. Workplaces, in particular, become so familiar to employees over time that it’s easy to miss vital signs especially when they’re busy. Even new signs alerting people to spills and trip hazards, building work or in response to an unexpected event like COVID-19 may fail to drive the right behaviours because messages are lost in the ‘background noise’ of other communications.

“This is why growing numbers of businesses and public sector organisations, including warehouses, offices, colleges and hospitals, no longer rely on visual cues alone. Instead, they’re combining their visual safety messages with audio – using ‘talking signs’ to communicate critical messages. An audio-visual sign helps to protect everyone, whether or not they’ve had formal health and safety training, so it’s good for suppliers and visitors to a site, as well as employees. It also means that people who prefer to hear instructions out loud aren’t disadvantaged compared to those who respond better to visual or written messages.”

The world is changing quickly, says Seton, so organisations need to continually review the effectiveness of their current signage and adapt quickly to new and existing hazards as they emerge. By taking a flexible approach, you can drive up safety standards and reassure staff, customers and visitors that you take your responsibilities seriously.