Not true at all. There's literally videos from FDNY chiefs circulating on the NYC news shows complaining about this problem and how it affects them because they're mad about not being exempted.
https://nypost.com/2022/06/07/off-duty-firefighter-saves-chi...
https://www.reddit.com/r/Firefighting/comments/w008we/do_you...
Firefighter gear is covered in PFAS and is highly carcinogenic. I don't want them bringing that shit on the subway, no way.