What about making employers provide a safe working environment?

We're already making them take a hand in enforcing the law. That doesn't deputize them in any way.

As for "refusing a lawful request" you're conflating legal terms. A "lawful request" exists in the context of HIPPA disclosure, to indicate that the requesting party has the legal right to request such information that is otherwise protected by medical privacy laws.

The term for an in-person LEO interaction is "lawful order". In that case, there are no bright lines defining what constitutes a lawful order, however the key point is that it is illegal to refuse to comply with what is deemed to be a lawful order. And in the case where an LEO is requesting entry to private property, without a warrant (or exigent circumstances that would otherwise allow their entry) there can not be a "lawful order" to grant access.

Any other handwaving?