Just as if you were wearing PPE, your first steps are to alert management and seek medical attention.
However, you likely do not have the same range of options afterwards.
Although you may receive worker’s compensation, you may not be able to hold your employer accountable for your disregard for PPE. Especially if your managers taught you how and when to use PPE, as per legislation.
Because of this, company policy will generally determine a course of action.