StacksVerified U.S. regulatory reference

30 CFR §18.22

Verified against eCFR.gov as of June 20, 2026View official text on eCFR.gov ↗
Each boring-type continuous-mining machine that is submitted for approval shall be constructed with an unobstructed continuous space(s) of not less than 200 square inches total cross-sectional area on or within the machine to which flexible tubing may be attached to facilitate auxiliary face ventilation.