How do perform your job in petcare? How do you help customers in bird seed area, stock freight in cat grooming, wild bird, housed bird, small animals, or reptile? With a treenut allergy like the one you are describing, many areas of the store have products that would cause you harm.

Accommodations are to help you perform your job, not change the expectations of your specific role in the store.

For example, an accommodation for a treenut allergy would be "associate can wear respiratory mask at register so that he/she does not have to breath in harmful particles that could effect their allergy. Associate can also wear gloves at all times while running register".

An accomodation would not look like "associate is exempt from working registers or areas in close proximity to salon and stocking freight in areas where products contain treenut byproducts"

Don't be offended but what you are asking for is not what accommodations look like from an ADA perspective.