Hi there ... with 30 years in the trade I would not be willing to risk it either .. I know that's not what you want to hear. You would be protected somewhat with a cap or foils but you don't need to come into direct contact to set off a reaction ... I use household bleach with gloves and I still get a rash on the inner elbow !!!
There are so many health and safety rules these days I can see why your hairdresser is playing safe.
i once refused to perm a client who had been using henna colour and explained why ... she went down the road to get it done ... came back in tears with dark green hair ... really.
Play safe please and trust your stylist
EK xx