R 325.50257 Respiratory protection.

Rule 7. (1) An employer shall implement a respiratory protection program in accordance with Occupational Health Standard Part 451 “Respiratory Protection,” as referenced in R 325.50252, when respirators are required by this rule. (2) Abrasive-blasting respirators shall be worn by all abrasive-blasting operators in all of the following situations: (a) When working inside blast-cleaning rooms. (b) When using silica sand in manual blasting operations where the nozzle and blast are not physically separated from the operator in an exhaust-ventilated enclosure. (c) Where concentrations of toxic dust dispersed by the abrasive blasting may exceed the exposure limits set in Occupational Health Standard Part 301 “Air Contaminants for General Industry,” as referenced in R 325.50252, and the nozzle and blast are not physically separated from the operator in an exhaust-ventilated enclosure. (3) Employers may use properly fitted particulate-filter respirators, commonly referred to as dust-filter respirators, for short, intermittent, or occasional dust exposures such as cleanup, dumping of dust collectors, or unloading shipments of sand at a receiving point when it is not feasible to control the dust by enclosure, exhaust ventilation, or other means. The respirator used shall be for protection against the specific type of dust encountered. (4) Dust-filter respirators may be used to protect the operator of outside abrasive blasting operations where nonsilica abrasives are used on materials that have low toxicities. (5) Dust-filter respirators shall not be used for continuous protection if silica sand is used as the blasting abrasive or if toxic materials are blasted.