Section 75.150 - Tests for methane and for oxygen deficiency; qualified person(a) The provisions of Subpart D-Ventilation of this part and § 75.1106 require that tests for methane and for oxygen deficiency be made by a qualified person. A person is a qualified person for this purpose if he is a certified person under § 75.100 .(b) Pending issuance of Federal standards, a person will be considered a qualified person for testing for methane and for oxygen deficiency: (1) If he has been qualified for this purpose by the State in which the coal mine is located; or(2) The Secretary may qualify persons for this purpose in a coal mine in which persons are not qualified for this purpose by the State upon an application and a satisfactory showing by the operator of the coal mine that each such person has been trained and designated by the operator to test for methane and oxygen deficiency and has made such tests for a period of 6 months immediately preceding the application. Applications for Secretarial qualification should be submitted to the Health and Safety Activity, Mine Safety and Health Administration, Certification and Qualification Center, P.O. Box 25367, Denver Federal Center, Denver, Colo. 80225.35 FR 17890, Nov. 20, 1970, as amended at 43 FR 12320, Mar. 24, 1978