No compensation shall be payable if the injury or death to the employee was proximately caused by:
(1) His intoxication, provided the intoxicant was not supplied by the employer or his agent in a supervisory capacity to the employee; or
(2) His being under the influence of any controlled substance listed in the North Carolina Controlled Substances Act, G.S. 90-86, et seq., where such controlled substance was not by prescription by a practitioner; or
(3) His willful intention to injure or kill himself or another.
When the injury or death is caused by the willful failure of the employer to comply with any statutory requirement or any lawful order of the Commission, compensation shall be increased ten percent (10%). When the injury or death is caused by the willful failure of the employee to use a safety appliance or perform a statutory duty or by the willful breach of any rule or regulation adopted by the employer and approved by the Commission and brought to the knowledge of the employee prior to the injury compensation shall be reduced ten percent (10%). The burden of proof shall be upon him who claims an exemption or forfeiture under this section.
"Intoxication" and "under the influence" shall mean that the employee shall have consumed a sufficient quantity of intoxicating beverage or controlled substance to cause the employee to lose the normal control of his or her bodily or mental faculties, or both, to such an extent that there was an appreciable impairment of either or both of these faculties at the time of the injury.
A result consistent with "intoxication" or being "under the influence" from a blood or other medical test conducted in a manner generally acceptable to the scientific community and consistent with applicable State and federal law, if any, shall create a rebuttable presumption of impairment from the use of alcohol or a controlled substance.