Section 325.52912. Ventilation in confined spaces.

(1) Air replacement. All welding and cutting operations carried on in confined spaces shall be adequately ventilated to prevent the accumulation of toxic materials or possible oxygen deficiency. This subrule applies not only to the welder but also to helpers and other personnel in the immediate vicinity. All air replacing the ventilated air withdrawn shall be clean and respirable.

(2)    Airline respirators. In circumstances for which it is impossible to provide such ventilation, airline respirators or hose masks approved for this purpose by NIOSH under C.F.R. Title 42, Part 84, as adopted by reference in R 325.52902, shall be used.

(3)  Self-contained units. In areas immediately hazardous to life, a full-facepiece, pressure- demand, self-contained breathing apparatus or a combination full-facepiece, pressure-demand supplied-air respirator with an auxiliary, self-contained air supply approved by NIOSH under

C.F.R. Title 42, Part 84, as adopted by reference in R 325.52902, shall be used.

(4)  Outside helper. Where welding operations are carried on in confined spaces and where welders and helpers are provided with hose masks, hose masks with blowers or self-contained breathing equipment approved by the mine safety and health administration and NIOSH, a worker shall be stationed on the outside of such confined spaces to ensure the safety of those working within.

(5)   Oxygen for ventilation. Oxygen shall not be used for ventilation.

History: 2015 AACS.