30 CFR § 57.5044
Respirators
July 29, 2020
In environments exceeding 1.0 WL, miners shall wear respirators approved by NIOSH for radon daughters prior to July 10, 1995 or under the equivalent section of 42 CFR part 84 and such respirator use shall be in compliance with §57.5005.
[60 FR 30400, June 8, 1995]