I have not flown Aer Lingus in many years so they are the ones to ask. The questions I have:
Is this a flight from the US to Ireland? Or is it within Europe? Will the aerosol can be in your checked luggage or carry-on? Is what is contained in the can considered a toiletry?
Aerosol cans are allowed in checked baggage as long as they are not huge cans, keep under 12 ozs to be on the safe side and make sure it is not flammable. that is why they take them in checked baggage. With carry on it has to be less than 3.4 oz. No one needs to take huge cans of anything, there are small cans of everything now to buy. I have even found small contact solution.