I don't know, but it seemed like common sense to me.
The final version of Rule 634.3 states
“All workers within the right-of-way of a Federal-aid highway who are exposed either to traffic (vehicles using the highway for purposes of travel) or to construction equipment within the work area shall wear high-visibility safety apparel. Firefighters or other emergency responders working within the right-of-way of a Federal-aid highway and engaged in emergency operations that directly expose them to flame, fire, heat,
and/or hazardous materials may wear retroreflective turn-out gear that is specified and regulated by other organizations, such as the National Fire Protection Association. Firefighters or other emergency responders working within the right-of-way of a Federal-aid highway and engaged in any other types of operations shall wear high-visibility safety apparel.”
I agree, it makes total sence and I must say that here in Northerm Michigan it seems like everyone is doing a great job in wearing them from fire, law, ems and even the towing guys.
This is a reason why there is an exemption in the law for those engaged in operational duties such as fire suppression. They can't make turnout gear a brighter color because the pbi material can only be dyed to certain colors. Additionally adding more reflective stripe on turnouts brings about other risks.
If there was a fire retardant material that is florescent lime green they would make every vest out of it.
That was my point. From day one, rule or no rule, we didn't wear them in the hazardous areas such as fire or where there was the chance of fire or chemical release. It was common sense.
The vest were not then, and are not now fire or chemical resistant. Our EMS crews, Chiefs or command, and ancillary personnel not involved in the "hot zone" wear theirs. When the extrication is complete, or the fire hazard has been mitigated, then the rest of the crew dons their vest. It was common sense.
Now it is "legal" common sense.
As far as the gear being a brighter color, I have been told by a certain manufacturer that it has something to do with the chemical composition of the fabric which does not allow for different or brighter colors.