Also, very sympathetic with the inventor being upset with use of the symbol out of it's place, thereby reducing it's effectiveness. This seems like one instance where copyright law should be implemented and strictly enforced, some kind of license free-to-use for actual biohazards but not anything else.
"Johnson & Johnson has registered the symbol for their medicinal products."
How did this ever get approved?
"The appropriation of the symbol has led to further irritation due to the practice of hospitals, first aid teams, and ski patrols in the United States reversing the symbol to a white cross on a red background – so undoing the original idea of the Red Cross emblem, namely reversing the Swiss flag – thus inappropriately suggesting an affiliation with Switzerland."
I imagine many other video games violate the Geneva convention!
Secondly, copyright holder can die, coupyright could be sold, and new owner could be irresponsible, litigious, and repurpose the symbol for a brand of coffee.
Then what, should all labs and scientists in the world find a new symbol?
The only solution is to treat misuse of the symbol same way we treat misusing emergency services.
I was first thinking of laws, but they are slow & contentious to pass (esp with one party consistently acting in bad faith), so I quickly landed on copyright, which of course has all the problems you cite and more.
Maybe start with (C), and pass laws to implement your solution? Or, maybe there's a way prosecutors can leverage existing laws.
Of course, that shirt is for sale in Australia and I have no idea what fair use encompasses there.
(Also, the design aesthetic of that shirt is atrocious in every sense.)