My official question to OSHA was…
Recently, OSHA issued an LOI aligning with NFPA 350 regarding PRCS isolation. In particular, OSHA stated that a pipe passing through a PRCS but not terminating within the space would NOT have to be isolated and evacuated. I want to know if this practice would be acceptable if the employer were to "reclassify" the PRCS to non-PRCS using 1910.146(c)(7) or 1926.1203(g). Both of those standards state that there can not be a known or "potential" atmospheric hazard. Having a 1" liquid NH3 line with about 2,000 pounds inside the space, inside piping/tubing that was not installed per ASME B31.3 or 31.5, and is not in an inspection/testing program because the facility is NOT a PSM/RMP facility, is a SUPER RISKY approach to reclassifying a PRCS. According to Merriam-Webster, "potential" is defined as "
existing in possibility; capable of becoming or developing into something in the future".
With the material in the piping inside the space, is there not a "potential", therefore, the space would not be eligible for "reclassification"? Maybe we could leave the piping charged with the hazardous chemical and do the entry as a "permitted entry" with all of the requirements of (d)-(k) in place?
OSHA’s response: (emphasis by me)
Thank you for your inquiry to OSHA concerning whether a permit-required confined space may be reclassified as a non-permit required confined space when a 1-inch liquid ammonia line containing approximately 2,000 pounds of ammonia remains within the space, and where the associated piping or tubing was not installed in accordance with ASME B31.3 or ASME B31.5 and is not included in an inspection or testing program because the facility is not subject to the Process Safety Management (PSM) or Risk Management Program (RMP) standards.
OSHA’s LOI on isolation for a pipe merely passing through a PRCS addresses whether that line must be isolated for a permit entry. It does not automatically mean the space can be reclassified under 29 CFR 1910.146(c)(7) or 1926.1203(g). For reclassification, ALL actual or potential atmospheric hazards MUST be eliminated without entry.
If a charged 1-inch liquid ammonia line remains in the space, especially where the piping is not designed, maintained, inspected, or tested under a recognized program, there is a credible possibility of a leak or release. That is enough to support the conclusion that a potential atmospheric hazard remains. In that case, the space would generally NOT qualify for reclassification. So, while OSHA may allow the line to remain charged for a permit-required entry under certain circumstances, leaving it in service would likely be inconsistent with reclassifying the space to a non-permit space unless the employer can demonstrate that no potential atmospheric hazard exists. Accordingly, the more defensible approach would be to treat the entry as a permit-required confined space entry and comply with the full permit requirements in 1910.146(d)-(k) or the corresponding construction provisions in 1926 Subpart AA.