It’s liability.

Don’t underestimate how almost every policy or protocol in every hospital, business, corporation, etc is designed in order to reduce liability with little else in mind.

Their argument would likely be that the hospital can not guarantee that a privately sourced PPE device will match the performance of the approved hospital standard, and they could claim any number of things such as the amount of fake N95’s circulating online. Should someone fall ill and die due to a deficient or defective PPE mask that was sourced privately, and the hospital allowed it to be used, they would be facing liability for that.

Liability motivates all in the US. Any time you hear of a nonsensical policy or decision from a company, it’s due to a liability issue you just haven’t fully considered. Doesn’t make it morally right, but that’s the reasoning.

For the record I highly disagree with what happened here and believe emergency situations call for “emergency policy changes.”