Theoretically, you could gamble with unsafe acts and never be injured. A common example of this is people who use a lawnmower without eye protection. One person might engage in this unsafe behavior for years without an eye injury and thus conclude it’s actually safe after all. However, every lawn mower manufacturer includes a warning not to operate the machine without eye protection and (except for electric mowers, which are quiet) hearing protection. Mowing weekly every summer without hearing protection would seem to have no ill effect, until you go for that hearing exam shortly after you turn 50.
Just because you don’t wear your safety glasses doesn’t mean you will automatically suffer an eye injury. Relying on this fact as a reason not to wear them is false logic. It’s akin to saying that just because you run across a highway doesn’t mean you will automatically get run over by a semi tractor trailer. Luck would probably be on your side the first few times. But eventually, you are going to get run over.
In the typical factory, employees can get by without wearing safety glasses and maybe for a long time nothing serious will happen. The same is true on the typical electrical install job. It’s also true that if you gave ten of those employees a pair of dice, it’s unlikely anyone would roll a three twice in a row. But unlikely doesn’t mean impossible — it just means as long as your luck holds. It is also fairly likely that one or more of those employees will roll a two with one die and a one with the other. If you add a third die, the chances of hitting a one on each die at the same time are much less than hitting a total of three with only two dice.
Let’s say there’s some strange science fiction at work with those dice. If anyone ever rolls a three (even once), that person will suffer a severe injury or maybe even die. Now it becomes imperative that nobody rolls a three. How might you prevent this? You could add another die, thus ensuring the minimum total for a given roll is four, or you could ban dice entirely. Notice that neither solution relies on luck.
Now let’s translate this dice rolling over to something electricians do every day. That is, take a voltage measurement. But now we are talking basic physics (not strange science fiction) when looking at what could happen. Suppose you are the electrician. You came out of an electronics background, where there’s no way to get an ionization trail going with those 5V circuits. So you developed the habit of checking voltages with a probe in each hand. In this case, your safety did not depend on luck.
Then you get hired into a maintenance job, and due to your electronics background, you get assigned to work on electronic motor drives. Immediately, the dynamics change. Now you’re working with a 480VAC circuit. And if you go back to the branch circuit overcurrent protective device (OCPD) in the distribution panel, you are exposed to many 480V circuits. You might still be lucky and never create an ionization trail or maybe create one that doesn’t quite cross the threshold for creating an arc fault or arc blast.
If you perform a cost/benefit analysis on taking a voltage measurement two probes at a time versus one probe at a time, you find no difference in cost. It really takes no more time one way versus the other. On an individual anecdotal incident basis, you might also find no difference in benefit. However, if you look at the aggregated data, you find an enormous difference in benefit. The same holds true for wearing safety glasses, putting your earmuffs on, and many other safety practices. They are practically free to implement, and, in the aggregate, very costly not to implement.
This kind of cost/benefit analysis is how to correctly evaluate whether to implement or not implement a given safety practice. Don’t look at isolated anecdotes or small sample sizes. A small sample size, for example, is one electrician over a span of 20 years (just got lucky and never rolled a three). Aggregated data show a much more accurate, reliable picture. And the kicker is that you don’t even have to look at the data. This has already been done for you, and the results are embedded into OSHA regulations, NFPA 70E, and industry standard practices.
Rather than roll the dice and eventually lose all your chips, stay out of the safety casino in the first place.
