10.C Controls.
10.C.01 All welding, cutting, and heating operations must be ventilated (natural or mechanical) such that personnel exposures to hazardous concentrations of airborne contaminants are within acceptable limits. > See Section 06.
10.C.02 Welding, cutting, and heating not involving conditions or materials described in this Section may normally be done without mechanical ventilation or respiratory protective equipment.
10.C.03 Either general mechanical or local exhaust ventilation must be provided whenever welding, cutting, or heating is performed in a confined space. > See Sections 10.A.06.d and 10.C.05.
10.C.04 Materials of toxic significance. Welding, cutting, or heating operations that involve or generate any of the substances listed below must be performed in accordance with the following subparagraphs: Antimony, Arsenic, Barium, Beryllium, Cadmium, Chromium, Chromium (VI), Cobalt, Copper, Lead, Manganese, Mercury, Nickel, Ozone, Selenium, Silver, or Vanadium. > See also Section 10.A.06.d.
- Whenever these materials are encountered in confined spaces, local mechanical exhaust ventilation and personal respiratory protective equipment must be used. The use of local mechanical exhaust ventilation systems that permit the re-entry of exhaust air back into the work area, or local exhaust which incorporate a system for the filtration and recirculation of exhaust air back into the work area must not be permitted.
- Whenever these materials, except beryllium and chromium (VI), are encountered in indoor operations, local mechanical exhaust ventilation systems that are sufficient to reduce and maintain personal exposures to within acceptable limits must be used and maintained in accordance with manufacturer's instruction. Care must be taken to ensure replacement filters are from the same manufacturer and are the correct filter for the exhaust system. When either beryllium or chromium (VI) is encountered in indoor operations, approved local mechanical exhaust ventilation systems and personal respiratory protection must be used.
- (1) In areas where only welding is conducted, a general exhaust system ventilation rate of 2,000 CFM per welder is required in open welding areas.
- (2) Local exhaust ventilation should have a capture velocity of 100 FPM as measured from the farthest distance from the work, and a duct transport velocity of 1,000 FPM minimum. Local exhaust ventilation systems which filter and return the air back into the work environment must be allowed for welding, that is not in a confined space or does not include beryllium or chromium, if the provisions of Section 06.H.01.f. are followed.
- Whenever these materials, except beryllium and chromium (VI), are encountered in outdoor operations, and local mechanical exhaust ventilation systems sufficient to reduce and maintain personal exposures to within acceptable limits are not provided, then appropriate respiratory protective equipment must be used.
- Whenever beryllium and chromium (VI) are encountered in outdoor operations, the need for and type of engineering and work practice controls to be implemented, as well as the need for and type of respiratory protection to be provided must be based upon the results of an initial worker exposure assessment and exposure determination with regards to these substances.
- Workers may be exposed to hazardous concentrations of chromium (VI) while welding, cutting or performing hot work on stainless steel, high chrome alloys or chrome- coated metal, or during the application and removal of chromate-containing paints and other surface coatings. > See Section 06.L.
- Workers working with materials of toxic significance, must remove outer clothing, vacuum off, and wash before taking a break, drinking, smoking, or leaving for the day.
- A good housekeeping plan must be developed and implemented for all work areas where welding, cutting, or heating operations involve materials of toxic significance. The plan must require all surfaces to be regularly HEPA vacuumed and wet wiped. The frequency must maintain the surfaces free of contamination and will be dependent on the frequency, type, and volume of welding, cutting, or heating completed in the area.
10.C.05 Welding, cutting, or heating operations that involve or generate fluorine or zinc compounds must be performed in accordance with the following:
- In confined spaces, local mechanical exhaust ventilation and personal respiratory protection sufficient to maintain exposures to within acceptable limits must be used.
- In open spaces, sampling must be performed as required and following the procedures in Section 6.A.01 to determine concentrations of fluorides or zinc compounds and the need for local exhaust ventilation and personal respiratory protection sufficient to maintain exposures to within acceptable limits.
10.C.06 Arc and gas cutting. Oxygen cutting using either an iron powder or chemical flux, gas-shielded arc cutting, and plasma cutting must employ local mechanical exhaust ventilation or other means adequate to remove the fumes generated.
10.C.07 Other persons exposed to the same atmosphere as welders or cutters must be protected in the same manner as welders or cutters.
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10-3. What kind of ventilation is required whenever welding, cutting, or heating is performed in a confined space?
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