Asked by: Alex Round, London
Even if you are allergic to peanuts, the smell of peanut butter won’t set off a reaction. Chemicals called pyrazines cause the smell, whereas the peanut proteins that cause the allergy aren’t normally volatile enough to inhale as an aroma. Cooking can release large enough particles to set off allergies to many foods; even then it isn’t the smell that is triggering this, it’s the cloud of food proteins.
There is, however, a phenomenon known as ‘chemical sensitivity’. Here, sufferers report headaches and nausea from the aroma of paint fumes and perfume. This isn’t medically recognised in the UK, though, and it certainly does not count as an allergy.
Read more:
Subscribe to BBC Focus magazine for fascinating new Q&As every month and follow @sciencefocusQA on Twitter for your daily dose of fun science facts.
