Using spray where one was justified in using deadly force could be acceptable but maybe not wise.
Using deadly force where one was only justified in use a lesser degree of force will land one in a lot of trouble.
Using force that causes some one permanent damage may or may not be justifiable.
Using pepper spray is not considered to be causing permanent damage. Where other sprays that have not been developed for use against humans or animals might be considered excessive.
If I have something under my sink, and I grab and use it to ward someone off, they’ll regret it if they decide I was in error to use whatever I had on hand. I will use that soapbox.