OSHA may use its General Duty Clause (GDC) to require employers to install oxygen monitors in areas where inert cryogenics are stored or used. But I like to use codes/standards (e.g., RAGAGEPs) to guide my safety engineering for these hazardous processes, even though PSM/RMP does not cover them. To do this, I turn to the International Fire Code (IFC) applicable to my state. Here is the language from the IFC regarding Inert Cryogenics, but this code references the standard where the actual requirement resides…
from the 2012 IFC
| SECTION 5501 GENERAL 5501.1 Scope. Storage, use and handling of cryogenic fluids shall comply with this chapter. Cryogenic fluids classified as hazardous materials shall also comply with Chapter 50 for general requirements. Partially full containers containing residual Cryogenic fluids shall be considered as full for the purposes of the controls required. Exceptions: 1. Fluids used as refrigerants in refrigeration systems (see Section 606). 2. Liquefied natural gas (LNG), which shall comply with NFPA 59A. Oxidizing cryogenic fluids, including oxygen, shall comply with NFPA 55 and Chapter 63, as applicable. Flammable cryogenic fluids, including hydrogen, methane, and carbon monoxide, shall comply with NFPA 55 and Chapters 23 and 58, as applicable. Inert cryogenic fluids, including argon, helium, and nitrogen, shall comply with CGA P-18. |
So we turn to CGA P-18 and we see the following:
| 5.2 Indoor storage Containers shall be designed, constructed, and installed per Section 4 and the additional requirements in this section. When a bulk container or inert gas storage system is located in a building, room, or any indoor confined area, the following additional provisions apply. 5.2.1 Construction of indoor areas When a bulk inert gas storage system is installed in a building constructed of combustible materials or close to combustible materials or sources of heat that could endanger the integrity of the storage container, a fire detection system shall be provided. 5.2.2 Minimum ventilation rate Natural or mechanical ventilation shall be provided when bulk inert gas systems are installed in buildings, rooms, or any indoor confined area. Ventilation shall be provided throughout the space at the rate of not less than 1.0 ft3/min • ft2 (0.00508 m3/s • m2) of floor area determined by the area enclosed. 5.2.3 Monitoring for oxygen deficiency INDOOR AREAS where bulk inert gas systems are installed shall be CONTINUOUSLY MONITORED with an atmosphere-monitoring system. The system shall provide an AUDIBLE AND VISUAL ALARM when the oxygen level drops to 19.5%. The alarm shall be located inside the area and immediately outside of all entrances to the indoor area. The atmosphere-monitoring system also shall send a signal to a central monitoring station or a continuously occupied location if one is provided on-site. The design of the monitoring system shall allow for ROUTINE TESTING TO DEMONSTRATE FUNCTIONALITY. 5.2.4 Warning signs Warning signs shall be posted at each entrance to the building, room, enclosure, or confined space where the bulk inert gas system is installed. Wording for such signs shall include the following as a minimum: WARNING – (Name of Gas) HIGH CONCENTRATION OF GAS CAN OCCUR IN THIS AREA AND CAN CAUSE ASPHYXIATION. VERIFY THAT OXYGEN CONCENTRATION IS ABOVE 19.5% BEFORE ENTERING AND DURING ACTIVITY IN THIS AREA. |