We have discussed this before; there is a significant difference between Recognized and Generally Accepted Good Engineering Practices (RAGAGEPs) and OSHA’s minimum performance compliance standards. OSHA standards may be adequate when quantities of the hazardous material(s) are managed at a lower inventory level; however, once those inventory levels exceed the PSM/RMP threshold, the old minimum standards are NOT adequate for those of us trying to design safety systems for these processes. We can use 1910.106 as our example again.
The ONLY place in 1910.106 that requires OVERFILL protection is when the storage tank is located “inside.” OSHA does not require overfill protection on flammable liquid storage tanks located outside, a significant miss, as overfill events are the leading cause of LOPC events during transfer operations.
NFPA 30, a true RAGAGEP, requires overfill protection for Class I and II flammable liquid storage tanks larger than 1,320 gallons.
| 21.7.1* Prevention of Overfilling of Storage Tanks. Facilities with aboveground tanks larger than 1320 gal (5000 L) storing Class I or Class II liquids shall establish procedures or shall provide equipment, or both, to prevent overfilling of tanks. |
We can even see some process safety practices in the more recent editions of NFPA 30, where they speak to having instrumentation and written procedures when the transfer is from a marine vessel or pipeline.