Not to mention the hearing damage I do to my ears in these environments. I can't get into flow unless I literally cannot hear or see activity around me.
It's possible that escalating a "buy me PPE" request to the company lawyer could raise a few eyebrows into exactly what conditions you're being asked to work under.
In addition to being completely unable to filter out any distracting noise, I also have misophonia, so an open office is anything between distracting as all get-out and torture, but the headphones and some good loud music mitigate that greatly.
(I once worked between someone who tapped their feet and someone who drummed on the desk constantly. Those weeks were not productive, even with headphones.)