OSHA trumps Iowa OSHA.
Full stop.
Iowa has a division empowered by OSHA to enforce OSHA regulations on the state. Some states do the same with the EPA.
But in a case of a state being less restrictive than the federal level you go to the federal level unless you want to spend a lot of money to lose the case.
I have been doing this for over 20 years, and am pretty familiar with how regulatory things work here. What this does is give Iowa companies some breathing room till the fed enforcement starts. Saying “Well we do this in Iowa” to OSHA is a guaranteed way to end up with a big fine. Saying “Well this was the instruction given to us by our local regulatory arm. How can we come into compliancy?” Is a path to a reduced finding (it happens more often than you would imagine) but you will be forced to the federal standard if the federal agency chooses to enforce. Full stop.
Now all this depends on the USSC ruling. If I had to guess, Kim thinks it will be a strike down to the mandate.
Nope. It’s not that simple. The state plans are required to provide “at least as effective protection” as the federal osha requirements. Iowa (and a couple of other states) have determined that them their own COVID procedures do just that.
Now it’s true that OSHA can try to revoke those state plans if they actually don’t provide that level of protection, but that means substantial and protracted litigation on that front.
To revoke a state plan: OSHA has to navigate this mess:
https://www.osha.gov/laws-regs/regulations/standardnumber/1902/1902.49
That won’t be easy.