The board may, after a hearing pursuant to chapter thirty A, revoke, suspend, cancel the license or place on probation, reprimand, censure, or otherwise discipline a licensee upon proof satisfactory to a majority of the board that said person:—
(a) has obtained or attempted to obtain a license by fraud or deception,
(b) has been convicted of a felony or of a crime involving moral turpitude,
(c) has been grossly negligent in his practice of respiratory therapy,
(d) has been adjudged mentally ill or incompetent by the court of competent jurisdiction,
(e) has used drugs or intoxicating liquors to the extent which adversely affects his practice,
(f) has acted in a manner which is professionally unethical according to ethical standards of the profession of respiratory care.