DS has a peanut allergy (ingest). we have been to Five Guys and are just really careful when we go. we have less of a problem there versus places like Texas Roadhouse and Logan's, where people drop the shells all over the floor. those places do seem to irritate DS.
and most peanut oils are so refined that the allergen has been removed. chick-fil-a uses peanut oil. but it has never bothered DS because it has been refined and the allergen removed. his is not a life-threatening allergy (well, that we know. he hasn't had a lot of exposure to peanuts--just one cross-contamination that left him swollen and with difficulty breathing, but not anaphalactic.), and he has eaten at chick-fil-a without problems for years. from what i understand, some can tolerate peanut oil and some cannot. DS can. so, it isn't to say that everyone with a peanut allergy needs to avoid peanut oil.