Prior to secondary blasting, tests for methane shall be made in the mine atmosphere at blast sites by a competent person. Secondary blasting shall not be done when 0.5 percent or more methane is present.
Sec. Appendix I to Subpart T of Part 57--Standard Applicability by
Category or Subcategory
Subcategory I-A 57.2210157.2210357.2220157.2220257.2220457.2220557.2220657.2220757.2220857.2221157.2221457.2221557.2221757.2222057.2222157.2222257.2222457.2222757.2222857.2222957.2223457.2223757.2230157.2230257.2230657.2240157.2250157.2260157.22608
Subcategory I-B 57.2220157.2220257.2221757.2222257.2222757.2223157.2223257.2223457.2223857.2240157.22501
Subcategory I-C 57.2210257.2210457.2210657.2220157.2220257.2220357.2220957.2221057.2221257.2221657.2221757.2222257.2222557.2222757.2222857.2223357.2223557.2224157.2230357.2231057.2231357.2250157.22602
Subcategory II-A 57.2210157.2210357.2220157.2220257.2220457.2220557.2220657.2220757.2220857.2221257.2221457.2221557.2221957.2222057.2222157.2222257.2222757.2222857.2223057.2223257.2223557.2230157.2230457.2230757.2231157.2231257.2250157.2260357.22608
Subcategory II-B 57.2220157.2222757.2223157.2223257.2223557.2223857.2250157.22604
Category III 57.2210157.2210357.2220157.2220257.2220457.2220557.2220657.2220757.2220857.2221357.2221457.2221557.2221857.2222057.2222157.2222257.2222357.2222457.2222757.2222857.2222957.2223457.2223757.2230557.2230857.2250157.2260657.22607
Category IV 57.2210557.2220157.2222657.22227 57.2223257.2223557.2223957.22501
Subcategory V-A 57.2210157.2210357.2220157.2220257.2220457.2220557.2220657.2220757.2220857.2221257.2221457.2221557.2221857.2222057.2222157.2222257.2222757.2222857.2222957.2223457.2224057.2230157.2230257.2230957.2231257.2231457.2231557.2250157.2260557.22608
Subcategory V-B 57.2220157.2220257.2221857.2222257.2222757.2223157.2223257.2223457.2223857.2231457.22501
Category VI 57.2223157.2223257.2223657.22238