PA Mining Law - Section 273 (1) Practice test questions for the PA Mine Officials' Exam Progress Indicator: Question 2 of 14 2.  In accordance with 30 CFR §49.6(b)(3), mine rescue apparatus and equipment shall be maintained in a manner that will ensure readiness for immediate use.  The certification and the record of corrective action shall be maintained at the mine rescue station for a period of __________ and made available on request to an authorized representative of the Secretary. Choices: two years one year six months ninety days