Minn. R. 4731.2270
RESPIRATORY PROTECTION EQUIPMENT RESTRICTIONS
The commissioner may impose restrictions in addition to those under parts 4731.2240 , 4731.2260 , and 4731.2700 to: A. ensure that the respiratory protection program of the licensee is adequate to limit doses to individuals from intakes of airborne radioactive materials, consistent with maintaining total effective dose equivalent ALARA; and B. limit the extent to which a licensee may use respiratory protection equipment instead of process or other engineering controls.