I used to work at a coffee shop where two of my coworkers were allergic to peanuts (one was severely allergic). At the time, we carried muffins containing peanuts, and instead of not ordering these items, my manager just asked us to use individual pieces of wax paper whenever a customer ordered one (as opposed to using the tongs, which we used for everything in the bake case).
I don't think any of us remembered to use the wax paper since we were all used to using the tongs for everything. But I'm also fairly certain neither of my PA coworkers ate anything we carried at the coffee shop.
Neither of my PA coworkers ever had an allergic reaction at work, but was this situation handled correctly?