R 325.50256 Exhaust ventilation systems.

Rule 6. (1) An employer shall ensure that the construction, installation, inspection, and maintenance of exhaust systems conform to the principles and requirements set forth in ANSI Z9.3 “Spray Finishing Operations: Safety Code for Design, Construction, and Ventilation,” 1985 edition, and ANSI Z33.1 “Blower and Exhaust Systems for Dust, Stock and Vapor Removal or Conveying,” 1961 edition, as adopted in R 325.50252. (2) If dust leaks are noted, then repairs shall be made as soon as possible. (3) The static pressure drop at the exhaust ducts leading from the equipment shall be checked when the installation is completed and periodically thereafter to assure continued satisfactory operation. If an appreciable change in the pressure drop indicates a partial blockage, then the system shall be cleaned and returned to normal operating condition. (4) In installations where the abrasive is recirculated, the exhaust ventilation system for the blasting enclosure shall not be relied upon for the removal of fines from the spent abrasive instead of an abrasive separator. An abrasive separator shall be provided for this purpose. (5) The air exhausted from blast-cleaning equipment shall be discharged through dust-collecting equipment. Dust collectors shall be set up so that the accumulated dust can be emptied and removed without contaminating other working areas.