U List of Acronyms
UDMH (1, 1-Dimethylhydrazine), Airborne Contaminant, Exposure limit  GISO, §5155, & Appx A
Listed, Permissible Exposure Limits GISO, §5155, Table AC-1
Process safety management GISO, §5189, Appx A
ULTRA-VIOLET RADIATION, Eye protection GISO, §5079
UNDERFLOOR SPACE, Access Openings GISO, §3271
UNDERGROUND HIGH-VOLTAGE, Hazards Associated with
Cables, Conductors or Equipment, work on or near ESO-HV, §2943
Application of §2943 ESO-HV, §2943(a)
Grounding De-energized Cables, Conductors or Equipment ESO-HV, §2943(k)
Manholes, Vaults, & Similar Structures ESO-HV, §2943(b)
Confined Space Regulations, Mandated ESO-HV, §2943(b)
Trenches & Excavations ESO-HV, §2943(c)
Work Conditions
7500 Volts or Less, Working with ESO-HV, §2943(h)
In Excess of 7500 Volts, Working with ESO-HV, §2943(i)
De-Energized Cables, Conductors or Equipment, Working on ESO-HV, §2943(j)
Grounding De-Energized Conductors or Equipment ESO-HV, §2943(k)
UNDERGROUND MACHINES, Power Shutoff, per MSO  MSO, §7001
UNDERGROUND MINE OPERATIONS See MINING OPERATIONS
UNDERGROUND STORAGE, per MSO 
Combustible Liquids & Gases MSO, §7064
Fuels, Lubricants & Rope Dressing MSO, §7065
UNDERGROUND STORAGE TANKS    See also under TANKS, Flammable Liquid Storage
Grounding Electrode, Used as  ESO-LV, §2395.82
Installation of Underground Tanks GISO, §5597
Tank Openings Other Than Vents GISO, §5599 
Vents for Underground Tanks GISO, §5598 
Venting, Capacity of GISO, §5598, Table FL-18
Underground Tanks per PSO  PSO-R,T&H, §6807
UNDERHUNG SWING CUT-OFF SAWS, Woodworking GISO, §4306
Point of Operation Guarding GISO, §4306(e)
Shaper & Similar Equipment GISO, §4318.1
Wobble Saws, GISO, §4323
Wood Shaper & Similar Equipment GISO, §4318.1
UNDERSLUNG SAWS, Woodworking GISO, §4306
Point of Operation Guarding GISO, §4306(e)
UNFIRED PRESSURE VESSEL SAFETY ORDERS (UFPV)
Application/Scope of  UFPV UFPV, §450
Definitions in the UFPV  UFPV, §453
Exempted Pressure Vessels UFPV, §451
  Air Tanks  See AIR TANKS  
Ammonia Systems    See ANHYDROUS AMMONIA SYSTEMS
Anhydrous Ammonia Systems    See ANHYDROUS AMMONIA SYSTEMS
Certification of Inspectors
Air Tanks UFPV, §463
Containers other than Air, LPG, NH3 CNG & LNG  UFPV, Article 4
Safety Valves/Devices UFPV, §467(a)
Inspection & Maintenance UFPV, §467(b)
Design & Construction  UFPV, Article 2
Air Tanks  UFPV, §454
Ammonia (NH3) Tanks UFPV, §458
Compressed Natural Gas (CNG)
CNG Cylinders UFPV, §456
CNG Tanks  UFPV, §455
Liquefied Natural Gas (LNG)
LNG Cylinders  UFPV, §456
LNG Tanks  UFPV, §455
LNG Vaporizers UFPV, §457
Pressure Vessels, All Other UFPV, §467
Inspection
Air Tanks UFPV, §462
LNG Tanks UFPV, §454(e)
Tanks other than Air, LPG, NH3, CNG or LNG UFPV, §467(b)
Inspections Fees
LPG UFPV, §488
Inspector Certification
Air Tanks UFPV, §463
Liquefied Petroleum Gas (LPG) Systems    See LIQUEFIED PETROLEUM GAS (LPG) SYSTEMS 
Natural Gas (NG) Systems, Compressed & Liquefied  See NATURAL GAS (NG) SYSTEMS, Compressed & Liquefied 
Permit to Operate
Air Tanks UFPV, §461
LPG Systems UFPV, §470
Propane See LIQUEFIED PETROLEUM GAS
Repairs & Alterations
Air Tanks UFPV, §466
Anhydrous Ammonia Systems UFPV, §512
LPG Systems  UFPV, §494
NG Tanks, Piping & Vaporizers UFPV, §526 
Safe Practices UFPV, §560
Safety Devices & Systems, Air Tanks UFPV, §465
Secondhand & Used Pressure Vessels 
Other than Air, LPG, NH3, CNG or LNG, for UFPV, §460(b)
Variances from the UFPV  UFPV, §452
UNFIRED STEAM BOILERS, Entering of PSO-R,T&H, §6893
UNFIRED STEAM PRESSURE VESSELS, Entering  GISO, §3312
UN-HAIRING HIDES & SKINS, MACHINES GISO, §4519
Special Types Un-hairing Machines GISO, §4521
UNLOADING OPERATIONS
Electrical, Power Poles, Unloading of Poles  ESO-HV, §2940.8(a)
Forklift Operations, Loading & Unloading Platforms     GISO, §3650(t)
Trailers, Securing during forklifts Operations GISO, §3650(j)
Vehicles, Securing during forklifts Operations GISO, §3650(t)(22)
Loading Dock Operations GISO, §3336
Dock Plates GISO, §3337
Loading Ramps  GISO, §3337 
Logging Operations, Restraining Device, Use of during Unloading    LSSO, §6340(g)
Oil & Gas Production Operations
Liquids, Loading & Unloading Operations PSO-D&P, §6651
Loading & Unloading Platforms PSO-D&P, §6652
Wharves & Piers, at PSO-D&P, §6659
Oil & Gas Refinery, Transportation & Handling
High-Vapor Pressure Hydrocarbons PSO-R,T&H, §6881
Loading Platforms PSO-R,T&H, §6879
Loading & Unloading Operations PSO-R,T&H, §6880
Wharves & Piers PSO-R,T&H, §6891
Pile Driving Operations, Unloading Piles CSO, §1601
Tank Vehicle Tank Car Loading & Unloading  GISO, §5547
Plants, Bulk, Flammable / Combustible Liquids Loading & Unloading GISO, §5619 
Plants, Industrial, Tank Vehicle Tank Car Loading & Unloading  GISO, §5547
Plants, Processing, Flammable Chemical Operations
Tank Vehicle Tank Car Loading & Unloading  GISO, §5558
Powder-Actuated Tools, Unloading, when not in-use CSO, §1691(h)
Railroad, Tank cars
Compressed gases  UFPV, §560
Securing during forklifts Operations GISO, §3650(t)(23)
High-Vapor Pressure Hydrocarbons PSO-R,T&H, §6881
Loading Platforms PSO-R,T&H, §6879
Loading & Unloading Operations PSO-R,T&H, §6880
Wharves & Piers PSO-R,T&H, §6891
Trailers, Disconnected from Tractor, Securing during forklifts Operations GISO, §3650(j)
Vehicles, Securing during forklifts Operations GISO, §3650(t)(22)
UNSAFE TOOLS, Prohibited Use     GISO, §3556(c)
UPHILL SLOPE, Logging Operations LSSO, §6281(a)
UPPER HOOD, Radial Arm Saw, Blade Enclosure GISO, §4309(a)
URANIUM COMPOUNDS, Airborne Contaminant, Exposure limit GISO, §5155, & Appx A
Listed, Permissible Exposure Limits GISO, §5155, Table AC-1
UTILITY, PUBLIC
Boiler inspections B&FPV, §770
Demolition of Buildings, Notification of  CSO, §1735(a)
Electrical, Facilities
Access and workspace requirements ESO-HV, §2945
Underground Utilities, Determination of Location before Excavating CSO, §1541(b)
UTILITY POLES, Temporary wiring  ESO-LV, §2405.3