Based on my understanding of this question in my opinion atleast small sharp pain is worse so the cup would be more painful as it would spread that sensation over a large part of the body. (Hope this helps have a great day)
Sanitising is very important in a house hold but most importantly in the kitchen we have to always keep things clean and sanitise for the sake of our health and the people around us
Formaldehyde is an organic compound.
Reactivity is the name your looking for I believe.
