Using Pepper Spray Legally

What is the legal way to use pepper spray? Using pepper spray irresponsibly can incur criminal or civil liability. Spraying an innocent victim in the face can be a crime. Much like a punch in the face, it would be charged as assault or battery in most jurisdictions. The justification for using pepper sprays must either be self-defense from personal injury or an arrest situation, and the force must be reasonable under the circumstances. For example, the law says you can´t lawfully spray someone in the face for using obscene language or because you are simply afraid because they look mean.