Does saying "Be Careful" to someone help to become more aware of hazards?

Having been in the processing industry for many years I have heard the following conversations in several ways:

'We’ve been having accidents on site and we want to reduce them.’ ‘Do we know why?’‘Well, our investigations have shown that people aren’t paying attention.’‘Hey, that’s great. We can tell them to be more careful - I’ll bet they’ve never thought of that.’‘Well, obviously not; otherwise they wouldn’t be having accidents.’‘That’s agreed then. Let’s turn being careful into a pithy slogan and put some posters up.’

Is safety as simple as ABC (Always Be Careful)? Really? (~ Craig Marriot in Challenging the Safety Quo)

How many people do hear "Take Care"and "Be Careful" on a regular basis before starting a task? Does this really help to work safer? Professor Patrick Hudson used to say in college that if you ask people to pay attention that more actually goes wrong!

Well known scientists (like for instance Daniel Kahneman, Ap Dijksterhuis, Victor Lamme) have shown us that less than 5% of what we do we do consciously. And that is probably already on the high side. The conscious mind works like a house. It can only be in one room at the time. If we would act consciously in all we do we hardly would get anything done. Acting from the unconscious mind are the type of actions that have been embedded in our mind. Done without thinking. Maybe scaring, but, by far most what we do we do without "thinking". This also means that considering risks we do far more often than not without thinking. Scary? Think about driving. Have you never experienced that suddenly you realise you are 20 km further than you thought. You have overcome 20 km with quite a few hazards in between without thinking about them. You dealt with them safely but unconsciously.

Therefore, we have to program the unconscious mind to work safely. Working safely has to be embedded into the unconscious mind. How does it work?

It is done by repetitively feeding informal safety triggers and incentives, and authentically setting the example through repetitive and low profile imitations (Erik Deblonde, arbo 7/6|2016). It gets adopted and leads to, as we know "common sense", embedded into our unconscious system. Interesting to note is that these imitations are not fed through the "carrot and stick" method. These imitations are directly initiated by specific nerve cells known as mirror neurons.

When? With every task, with every job. And applying these imitations is not just the manager's job, its everybody's job. Monkey see, monkey do. And social pressure is powerful (I refer to the 'social proof', one of the six principals of persuasion by Dr. Robert Cialdini). If this takes place in organisations where there is a culture of psychological freedom to voice safe behaviour, and where questions may be asked, then hazards shall get addressed in a better way.

For instance consistently applying the right PPE for the job. Asking and checking for the physical and chemical risks before a line break. Asking and checking lock-out of all energy sources before working on a machine or system. Checking if the area is safely barricaded before a lifting job or doing a job at height (protecting for falling and falling objects), but also turning off mobile phone before start driving, and so on.

"Be Careful!" does hardly help to avoid unsafe behaviour, unless the addressee replies and asks if he or she might be overlooking something, because in that case the conscious mind has been triggered. But how often does that happen?