Plenty of people think they're "smart" - and assume they know better than a vague warning sign: When some people see a "Danger confined space" sign they're going to think the danger is banging your head on the low-ceiling; that's not the real danger of confined spaces: a bigger threat is unbreathable gasses, like CO2, that tend to pool at the bottom of confined spaces: that's often the real danger. But yet I've never seen a sign saying "Danger: confined space: CO2 pooling risk" or similar.
This. But the problem aren't the people, but the vague warning sign. Another example is
The problem is that many warning signs don't exist to warn people, but to prevent lawsuits. So they are phrased as generally as possible and often include false positives.
There’s no warning sign for CO2 risk that will work for a non-expert. You have to go for the basics (“risk of suffocation and death”) at that point, because no one knows that you can drown in CO2.
I disagree. I think that most of the population of United States would understand that oxygen deprivation is bad. I agree that coming up with verbiage for a sign that clearly communicates the correct intent would be difficult.
Plenty of people think they're "smart" - and assume they know better than a vague warning sign: When some people see a "Danger confined space" sign they're going to think the danger is banging your head on the low-ceiling; that's not the real danger of confined spaces: a bigger threat is unbreathable gasses, like CO2, that tend to pool at the bottom of confined spaces: that's often the real danger. But yet I've never seen a sign saying "Danger: confined space: CO2 pooling risk" or similar.