Some substances are more toxic than others. The toxicity of a substance is described by the types of effects it causes and its potency. 1  Types of Effects: Different chemicals cause different effects.
I think I remember reading that injured means bruises and lascerations, seriously injured meant hospital but not life threatening, critically injured meant hospital ICU time and fatally injured meant injuries leading to dying sometime later.
Serious injury means any injury which: (1) Requires hospitalization for more than 48 hours, commencing within 7 days from the date of the injury was received; (2) results in a fracture of any bone (except simple fractures of fingers, toes, or nose); (3) causes severe hemorrhages, nerve, muscle, or tendon damage; (4) involves any internal organ; or (5) involves second- or third-degree burns, or any burns affecting more than 5 percent of the body surface.