O List of Acronyms
OBJECTS, Lowering of, Protection from falling GISO, §3273(f)
OBSERVATION ELEVATORS 
Car & Counterweight Safeties ElevSO, §3035(h)(4)
Design & Construction ElevSO, §3113(a)
Enclosures of Hoistways  ElevSO, §3010(a)(1), Exception
Hoistway Access Switch ElevSO, §3021(k)(1), Exception
OBSTRUCTIONS, Prohibition
Exits     GISO, §3227(c)
Floors & Platforms  GISO, §3273(a)
Walkways    GISO, §3273(b)
Alternative Remedy (Padding & Warning) GISO, §3227(c)
Work Areas GISO, §3273
OCTACHLORONAPHTHALENE
Airborne Contaminant, Exposure limit GISO, §5155, & Appx A 
Listed, Permissible Exposure Limits GISO, §5155, Table AC-1
OCTANE, Airborne Contaminant, Exposure limit GISO, §5155, & Appx A 
Listed, Permissible Exposure Limits GISO, §5155, Table AC-1
ODOR, Lack of in Breathing Air GISO, §5144(i)
ODORIZED LNG, Requirement for UFPV, §527(b) 
O-ETHYL S-PHENYL ETHYLPHOSPHONODITHIOATE (Fonofos)
Airborne Contaminant, Exposure limit GISO, §5155, & Appx A
Listed, Permissible Exposure Limits GISO, §5155, Table AC-1
OIL, Dust Suppression Use GISO, §5145 
OIL FIRED HEATERS, Temporary CSO, §1693(f)
Fire-extinguisher Requirement for Temporary Heaters CSO, §1693(g)
OIL, Floors & Platforms, Free Of  GISO, §3273(a)
OIL STORAGE FACILITIES, Housekeeping of PSO-D&P, §6539
OIL SPILLS, Oil Storage Facilities PSO-D&P, §6539
OIL & GAS WELLS, Drilling & Production
Change Rooms 
Permanent Change Rooms, per   GISO, Article 9 PSO-D&P, §6514(a)
Clean, Orderly, Sanitary Condition PSO-D&P, §6514(b)
Location of PSO-D&P, §6514(c)
Shower Facilities, Number of PSO-D&P, §6514(a)
Well Drilling & Servicing Operations PSO-D&P, §6515
Clean, Orderly, Sanitary Condition PSO-D&P, §6515(b)
Lighting, Heating & Ventilation PSO-D&P, §6515(b)
Location of PSO-D&P, §6515(a)
Clothing, wearing of, per GISO, Article 10 PSO-D&P, §6513
Communication, Emergency PSO-D&P, §6512
Drainage control  PSO-D&P, §6538
Drilling Operation
Fall Protection Requirements, Derrick / Mast Work PSO-D&P, §6580
Tools, Handling Heavy Tools at Drilling Wells PSO-D&P, §6607
Electrical Equipment & Wiring per Electrical Safety Orders PSO-D&P, §6527
Emergency Escape, Auxiliary Means of  PSO-D&P, §6573
Emergency Medical Services PSO-D&P, §6512
Emergency Stop Device, Drilling Equipment PSO-D&P, §6625 
Equipment & Pipe Lines
Blinding or Isolating of Equipment & Pipe Lines PSO-D&P, §6536
Blinding Design PSO-D&P, §6536(b)
Open or Closed Indicators PSO-D&P, §6536(e)
Employee Protection by PSO-D&P, §6536(a)
Ventilation Requirements PSO-D&P, §6536(c)
Welding, Hot Work Method PSO-D&P, §6536(d)
Opening of Equipment & Pipe Lines PSO-D&P, §6535
Emptying of Content  PSO-D&P, §6535(b)
Ignition Source, Elimination of  PSO-D&P, §6535(c)
Relieve of Pressure PSO-D&P, §6535(a)
Equipment & Tools, Miscellaneous PSO-D&P, §6646
Escape, Auxiliary Means of  PSO-D&P, §6573
Fall Protection Requirements See FALL PROTECTION REQUIREMENTS, per PSO-D&P
Fire Prevention
Cleaning oil restrictions  PSO-D&P, §6520
Drainage control  PSO-D&P, §6538
Fired equipment location  PSO-D&P, §6526
Fire fighting equipment  PSO-D&P, §6519
Flammable and combustible liquid transfer by air displacement  PSO-D&P, §6525
Flammable waste gases and vapors  PSO-D&P, §6524
Hazardous area testing  PSO-D&P, §6521
Pipe lines
Blinding procedures  PSO-D&P, §6536
Opening procedures  PSO-D&P, §6535
Smoking restrictions  PSO-D&P, §6518
Spontaneous ignition precautions  PSO-D&P, §6522
Static electricity  PSO-D&P, §6523
First aid  PSO-D&P, §6511
Fittings, Pipe Lines & Valves PSO-D&P, §6533
Drill Pipe & Well Casing / Tubing Excluded PSO-D&P, §6533(a)
General Requirements PSO-D&P, §6533(a)
Inspection Requirements PSO-D&P, §6533(b)
Pressure Relieve Devices & Valves PSO-D&P, §6533(c)
Flammable Gases Or Vapors, Hazardous Areas    See FLAMMABLE GASES OR VAPORS, Hazardous Areas
Flammable Waste Gasses & Vapor See FLAMMABLE WASTE GASSES & VAPOR
Flywheel Guarding, Prime Movers PSO-D&P, §6682
Gas & Vapor testing  PSO-D&P, §6531
Hazardous Areas PSO-D&P, §6521
Control of Sources of Ignition  PSO-D&P, §6521(a)
Flammable Waste Gasses & Vapor PSO-D&P, §6524
Burning of, to Control PSO-D&P, §6524(a)
Control Hazards Associated with PSO-D&P, §6524(a)
Flares, use of PSO-D&P, §6524(a), (b), (c)
Employees Entry Restriction PSO-D&P, §6524(e)
Remote Ignition, Controlled PSO-D&P, §6524(b)
Remote Ignition, Failure PSO-D&P, §6524(b)
Release of Gasses & Vapor Prevention PSO-D&P, §6524(d)
Remote Ignition, Controlled PSO-D&P, §6524(b)
Testing for Releases before Employees Entry PSO-D&P, §6524(e)
Ignition Sources
Control of Use PSO-D&P, §6521(a)
Prohibited, in Flammable Vapor / Gas PSO-D&P, §6521(b )
Spontaneous Ignition  PSO-D&P, §6522
Iron Sulfide Management  PSO-D&P, §6522(a)
Steel Wool, use with Lime  PSO-D&P, §6522(b)
Static Electricity, Control of PSO-D&P, §6523(a)
Grounding of Steel Derricks & Masts PSO-D&P, §6523(b)
Testing of Gas & Vapor PSO-D&P, §6531
Transfer of Flammable / Combustible Liquids
Compressed Air, Use Prohibited for Tanks PSO-D&P, §6525(a)
Exceptions listed  PSO-D&P, §6525(a)
Well Safety
Electrical Equipment PSO-D&P, §6527
Fired Equipment Restriction near Wells PSO-D&P, §6526(a)
Safety Provisions & Precautions  PSO-D&P, §6655 
Heavy tool, Handling of   PSO-D&P, §6607
Housekeeping of Oil Storage Facilities PSO-D&P, §6539
Identification of Wells & Equipment PSO-D&P, §6556
Injury & Illness Prevention Program per  GISO, §3203 PSO-D&P, §6507
Safety Provisions & Precautions  PSO-D&P, §6655
Inspection Program, Pressure Vessels & Boilers PSO-D&P, §6551(c)
Internal combustion engines, Stationary, Precautions  PSO-D&P, §6554
Internal combustion engines, Stop Device, Emergency  PSO-D&P, §6625
Ladders, Derrick  PSO-D&P, §6564
Ladderway Openings, Platforms   PSO-D&P, §6565
Leakage control PSO-D&P, §6540
Lighting PSO-D&P, §6657
Liquids, Loading & Unloading Operations PSO-D&P, §6651
Loading & Unloading Platforms PSO-D&P, §6652
Wharves & Piers, at PSO-D&P, §6659
Loading & Unloading operations PSO-D&P, §6651
Platforms  PSO-D&P, §6652
Wharves & Piers, at PSO-D&P, §6659
Maintenance
Fall Protection Requirements, Derrick / Mast Work PSO-D&P, §6580
Mine & Tunnel Safety Orders Apply to Shafts & Equipment at Oil Wells PSO-D&P, §6661
Personal Protective Equipment,   per GISO, Article 10  PSO-D&P, §6513
Pipe Lines  See also Equipment & Pipe Lines under this heading
Fittings, Pipe Lines & Valves PSO-D&P, §6533
Drill Pipe & Well Casing / Tubing Excluded PSO-D&P, §6533(a)
General Requirements PSO-D&P, §6533(a)
Inspection Requirements PSO-D&P, §6533(b)
Pressure Relieve Devices & Valves PSO-D&P, §6533(c)
Pressure Vessels & Boilers, Inspection Program PSO-D&P, §6551(c)
Pull Rope, Wire PSO-D&P, §6640
Pumping Machinery & Equipment PSO-D&P, Article 37
Access to the Walking Beam PSO-D&P, §6632
Attractive Nuisance Guards: Well-Pumping Units PSO-D&P, §6633
Catheads PSO-D&P, §6642 
Chain Used for Spinning Lines  PSO-D&P, §6645
Lines Used on Catheads PSO-D&P, §6644
Construction & Maintenance PSO-D&P, §6630
Guarding PSO-D&P, §6631
Illumination / Lighting PSO-D&P, §6657
Pumps & Pump Pressure Relief Devices PSO-D&P, §6634
Safety Provisions & Precautions  PSO-D&P, §6655 
Shafts & Equipment at Oil Wells PSO-D&P, §6661
Weight Indicators for Wire Rope Hoisting Lines PSO-D&P, §6690
Safety Provisions & Precautions  PSO-D&P, §6655
Injury & Illness Prevention Program PSO-D&P, §6507
Servicing Machinery & Equipment PSO-D&P, Article 35
Application / Scope PSO-D&P, §6621
Brakes & Brake Control Mechanism PSO-D&P, §6626
Catheads  PSO-D&P, §6642 
Chain Used for Spinning Lines  PSO-D&P, §6645
Lines Used on Catheads PSO-D&P, §6644
Drilling Equipment, Construction & Maintenance PSO-D&P, §6624
Emergency Stop Device PSO-D&P, §6625
Emergency Stop Device PSO-D&P, §6655
Guarding PSO-D&P, §6622
Illumination / Lighting PSO-D&P, §6657
Line Spoolers & Deadline Stabilizers PSO-D&P, §6688
Power Tongs Control Mechanism PSO-D&P, §6628
Safety Provisions & Precautions  PSO-D&P, §6655
Weight Indicators for Wire Rope Hoisting Lines PSO-D&P, §6690
Well Servicing Equipment, Construction & Maintenance PSO-D&P, §6624
Shafts & Equipment at Oil Wells PSO-D&P, §6661
Shower Facilities, Number of PSO-D&P, §6514(a)
Storage Facilities, Housekeeping of Oils Storage PSO-D&P, §6539
Tools & Equipment  PSO-D&P, §6646
Tools, Handling Heavy Tools at Drilling Wells PSO-D&P, §6607
Traveling blocks  PSO-D&P, §6638
Tunnel & Mine Safety Orders Apply to Shafts & Equipment at Oil Wells PSO-D&P, §6661
Unloading & Loading Operations PSO-D&P, §6651
Platforms  PSO-D&P, §6652
Wharves & Piers, at PSO-D&P, §6659
Valves  PSO-D&P, §6533
Weight Indicators  PSO-D&P, §6690
Well Identification  PSO-D&P, §6556
Well-servicing machinery
Applicability  PSO-D&P, §6621
Guarding  PSO-D&P, §6622
Well Shafts  PSO-D&P, §6661
Construction and maintenance  PSO-D&P, §6576
Entrances & Exits  PSO-D&P, §6577
Wharves and piers  PSO-D&P, §6659 
OIL & GAS WELLS, Fire Hazard Control PSO-D&P, §6521
Control of Sources of Ignition  PSO-D&P, §6521(a)
Flammable Waste Gasses & Vapor, Hazard Control PSO-D&P, §6524
Burning, Controlled PSO-D&P, §6524(a)
Control Hazards Associated with PSO-D&P, §6524(a)
Flares, use of PSO-D&P, §6524(a), (b), (c)
Employees Entry Restriction PSO-D&P, §6524(b)
Location of PSO-D&P, §6524(c)
Remote Ignition, Controlled PSO-D&P, §6524(b)
Remote Ignition, Failure PSO-D&P, §6524(e)
Employees Entry Restriction PSO-D&P, §6524(b)
Remote Ignition, Controlled PSO-D&P, §6524(b)
Remote Ignition, Failure PSO-D&P, §6524(e)
Release of Gasses & Vapor Prevention PSO-D&P, §6524(d)
Remote Ignition, Controlled PSO-D&P, §6524(b)
Testing for Releases before Employees Entry PSO-D&P, §6524(e)
Ignition Sources
Control of PSO-D&P, §6521(a)
Prohibited, in Flammable Vapor / Gas PSO-D&P, §6521(b )
Spontaneous Ignition  PSO-D&P, §6522
Iron Sulfide Management  PSO-D&P, §6522(a)
Steel Wool, use with Lime  PSO-D&P, §6522(b)
Static Electricity, Control of PSO-D&P, §6523(a)
Grounding of Steel Derricks & Masts PSO-D&P, §6523(b)
Testing of Gas & Vapor PSO-D&P, §6531
Transfer of Flammable / Combustible Liquids
Compressed Air, Use Prohibited for Tanks PSO-D&P, §6525(a)
Exceptions listed  PSO-D&P, §6525(a)
Well Safety
Electrical Equipment PSO-D&P, §6527
Fired Equipment Restriction near Wells PSO-D&P, §6526(a)
Safety Provisions & Precautions  PSO-D&P, §6655 
OIL & GAS WELLS, Hazardous (Classified) Locations   ESO-LV, Article 60
Drilling Wells ESO-LV, §2548.22
General ESO-LV, §2548.21
Lighting Systems ESO-LV, §2548.26
Overload Protection ESO-LV, §2548.24
Producing Wells ESO-LV, §2548.23
Desander, Desilter, Illustrations ESO-LV, §2548.23, Figure 6
Mud Tanks, Illustrations ESO-LV, §2548.23, Figures 3, 4
Pump, Compressor, Illustrations ESO-LV, §2548.23, Figures 11, 12, 19
Shale Shaker, Illustrations ESO-LV, §2548.23, Figure 5
Vents, Misc, Illustrations ESO-LV, §2548.23, Figures 13-18
Well Head Illustrations ESO-LV, §2548.23, Figures 1-10
Wastewater Wells ESO-LV, §2540.10
Wiring Methods ESO-LV, §2548.25
OIL & GAS WELLS, Pumping Machinery & Equipment PSO-D&P, Article 37
Access to the Walking Beam PSO-D&P, §6632
Air Compressors, Engines Powering PSO-D&P, §6554
Attractive Nuisance Guards: Well-Pumping Units PSO-D&P, §6633
Boilers See BOILERS
Construction & Maintenance PSO-D&P, §6630
Dead line stabilizers  PSO-D&P, §6688
Derricks & Masts  PSO-D&P, §6558
  Construction and maintenance  PSO-D&P, §6568
Crown blocks  PSO-D&P, §6571
Crown platforms and railings  PSO-D&P, §6562
Equipment and tool requirements  PSO-D&P, §6603
Escape lines  PSO-D&P, §6574
Escape routes, Auxiliary Means  PSO-D&P, §6573
Equipment in  PSO-D&P, §6603
External platforms  PSO-D&P, §6561
Fingers finger boards and finger braces  PSO-D&P, §6569
Floor access and exits  PSO-D&P, §6579
Gin poles  PSO-D&P, §6563
Guy lines  PSO-D&P, §6566
Inside platforms  PSO-D&P, §6560
Ladders  PSO-D&P, §6564
Ladderway openings  PSO-D&P, §6565
Materials in  PSO-D&P, §6603
Safety belts and lanyards  PSO-D&P, §6580
Stabbing boards  PSO-D&P, §6570
Tools in  PSO-D&P, §6603
Diesel Engines, Over-Speed Protection PSO-D&P, §6554(h)
Electrical Equipment PSO-D&P, §6527
Escape routes, Auxiliary Means  PSO-D&P, §6573
Experimental equipment  PSO-D&P, §6886
Fittings, Pipe Lines & Valves PSO-D&P, §6533
Drill Pipe & Well Casing / Tubing Excluded PSO-D&P, §6533(a)
General Requirements PSO-D&P, §6533(a)
Inspection Requirements PSO-D&P, §6533(b)
Pressure Relieve Devices & Valves PSO-D&P, §6533(c)
Flares PSO-D&P, §6524
Burning of Waste Gases/Vapor PSO-D&P, §6524(a)
Employees Entry Restricted PSO-D&P, §6524(e)
Location of PSO-D&P, §6524(c)
Remote Ignition, Safe & Reliable Means PSO-D&P, §6524(b)
Prolonged Release of Gases/Vapor Prevention PSO-D&P, §6524(d)
Gas Compressors, Engines Powering PSO-D&P, §6554
Gas Compressors & Gas Plant Requirements PSO-D&P, §6553
Discharge Line, Pressure Relief Device Requirement PSO-D&P, §6553(b)
Discharge Outlet of Pressure Relief Device PSO-D&P, §6553(c)
Inlet Scrubber, Liquids in Incoming Gas PSO-D&P, §6553(d)
Pre-Maintenance Procedure, locking / Blocking PSO-D&P, §6553(f)
Shut-off Valve, Gas Line PSO-D&P, §6553(e)
Stationary Engine Driving Compressors  PSO-D&P, §6554
Valve, Return Flow Protection PSO-D&P, §6553(a)
Gas & Vapor testing  PSO-D&P, §6531
Guarding PSO-D&P, §6631
Heavy tool, Handling of   PSO-D&P, §6607
Hoses & Standpipes  PSO-D&P, §6609
Internal combustion engines 
Application / Scope of §6684  PSO-D&P, §6684(a)
Batteries, Electrical Storage PSO-D&P, §6684(h)
Compressors, Air or Gas PSO-D&P, §6554
Cylinder Cooks PSO-D&P, §6684(e)
Electrical Accessories for PSO-D&P, §6684(f), (g)
Electrical Storage Batteries PSO-D&P, §6684(h)
Exhaust System Maintenance  PSO-D&P, §6684(c)
Flywheels PSO-D&P, §6682
Power Controls  PSO-D&P, §6681
Safety Precautions PSO-D&P, §6684(b), (d), (g) 
For Compressors, Air or Gas PSO-D&P, §6554
Emergency Stop Device PSO-D&P, §6525
Starters PSO-D&P, §6685
Unloading & Loading Flammable Liquids PSO-D&P, §6651(c)
Ladders  PSO-D&P, §6564
Ladderway openings  PSO-D&P, §6565
Lighting PSO-D&P, §6657
Line spoolers  PSO-D&P, §6688
Locking Devices, Telescoping gin pole masts  PSO-D&P, §6584
Machinery
Brakes  PSO-D&P, §6626
Construction of  PSO-D&P, §6624
Emergency Stop Devices  PSO-D&P, §6625
Maintenance  PSO-D&P, §6624
Masts
Cantilever Derricks & Masts, Portable  PSO-D&P, §6595
Construction of  PSO-D&P, §6568
Crown blocks  PSO-D&P, §6571
Crown Platforms & Railings PSO-D&P, Article 25
Access & Lubrication  PSO-D&P, §6592(a)
Ladder Requirements  PSO-D&P, §6592(b)
Gin Pole Masts, Stationary or Portable  PSO-D&P, §6589
Portable Cantilever Derricks & Masts PSO-D&P, §6590
Portable Jackknife Derricks & Masts PSO-D&P, §6591
Telescoping Derricks & Masts PSO-D&P, §6591
Equipment and tool requirements  PSO-D&P, §6603
Escape lines.  PSO-D&P, §6574
Fire Escapes, Auxiliary Means  PSO-D&P, §6573
Fingers, Finger Boards & Finger Braces  PSO-D&P, §6569
Floor access and Exits  PSO-D&P, §6579
Guarding  PSO-D&P, §6636
Guying  PSO-D&P, §6586
Hydraulic lifts  PSO-D&P, §6583
Ladders.  PSO-D&P, §6599
Locking Devices, Telescoping gin pole masts  PSO-D&P, §6584
Maintenance  PSO-D&P, §6568
Pipelines & Pipes See PIPELINES
Pipe racking supports  PSO-D&P, §6596
Platforms Access Runways  PSO-D&P, §6594
Platforms, Crown, & Railings PSO-D&P, Article 25
Access & Lubrication  PSO-D&P, §6592(a)
Ladder Requirements  PSO-D&P, §6592(b)
Gin Pole Masts, Stationary or Portable  PSO-D&P, §6589
Portable Cantilever Derricks & Masts PSO-D&P, §6590
Portable Jackknife Derricks & Masts PSO-D&P, §6591
Telescoping Derricks & Masts PSO-D&P, §6591
Pole Steps  PSO-D&P, §6600
Portable telescoping derricks or masts  PSO-D&P, §6582
Safety belts and lanyards  PSO-D&P, §6580
Stabbing hoards  PSO-D&P, §6570
Telescoping gin pole masts, locking Devices  PSO-D&P, §6584
Walk and pipe storage racks  PSO-D&P, §6572
Mine & Tunnel Safety Orders Apply to Shafts & Equipment at Oil Wells PSO-D&P, §6661
Miscellaneous provisions PSO-D&P, §6646
Pipe lines  PSO-D&P, §6533
 ”              ” See PIPELINES
Blinding Procedures  PSO-D&P, §6536
Opening Procedures  PSO-D&P, §6535
Pipe Storage Racks  PSO-D&P, §6648
Pipe Tong Requirements  PSO-D&P, §6605
Power tongs, Control mechanisms  PSO-D&P, §6628
Pits and sumps  PSO-D&P, §6549
Power tongs, Control mechanisms  PSO-D&P, §6628
Pressure Relief Devices, Pressure Vessels & Boilers PSO-D&P, §6551
Pressure Relief Devices, for Pumps  PSO-D&P, §6634
Pressure Vessels & Boilers PSO-D&P, §6551
Inspection Program PSO-D&P, §6551(c) 
Prime Movers
Flywheels  PSO-D&P, §6682
Internal combustion engines PSO-D&P, §6684
Starters for PSO-D&P, §6685
Power control  PSO-D&P, §6681
Pull Rope, Wire PSO-D&P, §6640
Pumping Machinery & Equipment PSO-D&P, Article 37
Access to the Walking Beam PSO-D&P, §6632
Attractive Nuisance Guards: Well-Pumping Units PSO-D&P, §6633
Catheads PSO-D&P, §6642 
Chain Used for Spinning Lines  PSO-D&P, §6645
Lines Used on Catheads PSO-D&P, §6644
Construction & Maintenance PSO-D&P, §6630
Guarding PSO-D&P, §6631
Illumination / Lighting PSO-D&P, §6657
Pumps & Pump Pressure Relief Devices PSO-D&P, §6634
Safety Provisions & Precautions  PSO-D&P, §6655 
Shafts & Equipment at Oil Wells PSO-D&P, §6661
Weight Indicators for Wire Rope Hoisting Lines PSO-D&P, §6690
Shafts Pursuant to Tunnel Safety Orders PSO-D&P, §6661
Tanks & Reservoirs  PSO-D&P, §6546
Agitation and heating of liquids  PSO-D&P, §6544
Diversion and retaining walls  PSO-D&P, §6548
Maintenance  PSO-D&P, §6547
Tools & Equipment , Miscellaneous PSO-D&P, §6646
Tools, Handling Heavy Tools at Drilling Wells PSO-D&P, §6607
Traveling blocks  PSO-D&P, §6638
Tunnel & Mine Safety Orders Apply to Shafts & Equipment at Oil Wells PSO-D&P, §6661
Unloading & Loading Operations PSO-D&P, §6651
Internal Combustion Engines, during PSO-D&P, §6651(c)
Platforms  PSO-D&P, §6652
Vapor control, Flammable PSO-D&P, §6651(c)
Wharves & Piers, at PSO-D&P, §6659
Valves  PSO-D&P, §6533
Weight Indicators  PSO-D&P, §6690
Well Identification  PSO-D&P, §6556
Well-servicing machinery
Applicability /Scope PSO-D&P, §6621
Guarding  PSO-D&P, §6622
Well Shafts  PSO-D&P, §6661
Construction and maintenance  PSO-D&P, §6576
Entrances & Exits  PSO-D&P, §6577
Wharves and piers  PSO-D&P, §6659 
Wire Rope Hoisting Lines  PSO-D&P, §6690
Weight indicators  PSO-D&P, §6690(a)
Installation of  PSO-D&P, §6690(b)
Wire line Units PSO-D&P, §6688(a)
OIL & GAS REFINERIES  See REFINERIES, Petroleum
OIL MIST PARTICULATE, Airborne Contaminant, Exposure limit GISO, §5155, & Appx A
Listed, Permissible Exposure Limits GISO, §5155, Table AC-1
OILY RAGS, Storage & Disposal   GISO, §5562(c)
OLEUM (Fuming Sulfuric Acid, Sulfuric Acid), Airborne Contaminant 
Exposure limits  GISO, §5155, & Appx A
Listed, Permissible Exposure Limits GISO, §5155, Table AC-1
Process Safety Management GISO, §5189, Appx A 
ON-THE-JOB TRAINING See TRAINING 
OPENING PIPE LINES & EQUIPMENT  PSO-R,T&H, §6815 
OPENINGS, Access to Attic, Ceiling & Underfloor Spaces GISO, §3271
OPENINGS, Electrical Boxes, Cabinets, etc. shall be closed, High Voltage ESO-HV, §2714(c) 
OPENINGS,  Electrical Boxes, Cabinets, etc. shall be closed, Low Voltage ESO-LV, §2340.12(a)
OPENINGS, Floor     GISO, §3212
OPENINGS, Raises, Winzes, per MSO MSO, §7051
OPENINGS, Roof, per GISO GISO, §3212(e) 
OPENINGS, Roof, per CSO CSO, §1632(b)
OPENINGS, Skylight, per GISO GISO, §3212(e)
OPENINGS, Skylight, per CSO CSO, §1632(b)
OPEN SURFACE TANKS, Ventilation & PPE GISO, §5154
OPEN TANKS, Precautions, Cyanide  GISO, §5169
OPEN WIRING (Bare), High Voltage ESO-HV, Article 9
Application / Scope ESO-HV, §2755
Clearances over Driveways ESO-HV, §2758
Insulators ESO-HV, §2757
Spacing Between Bare Energized Parts & Adjacent Surfaces  ESO-HV, §2756
OPEN WIRING, Low Voltage  ESO-LV, Article 16
Conductor Supports ESO-LV, §2420.4
Exposed Wiring, Uses Permitted ESO-LV, §2420.3
Flexible Nonmetallic Tubing ESO-LV, §2420.5
Penetrations of Walls, Floors, Cross Members, etc. ESO-LV, §2420.6
Protection from Physical Damage ESO-LV, §2420.7
OPEN WIRES, Nonworking, per TelSO  TelSO, §8614(b)
OPERATING CONDITIONS, Safe, Machinery  GISO, §3328(g)
OPERATING INSTRUCTIONS, Aerial Devices  GISO, §3648
OPERATING PROCEDURES 
Cylinders & Containers  GISO, §4845(c)-(y)
OPERATING RULES
Agricultural Tractors GISO, §3664(b)
Cranes, Hoists & Derricks GISO, Article 98
Applications / Scope  GISO, §4990
Booms  GISO, §4992
Crane or Derrick Suspended Personnel Platform GISO, §5004(d)
Driver Position, during loading GISO, §4996
Fire Extinguisher GISO, §4997
Floor-Operated Cranes GISO, §5009
Handling Loads GISO, §4999
High Voltage Lines, Accident Prevention GISO, §5003
Hoisting  GISO, §4994
Limit Switches, testing GISO, §5000
Manbasket / Suspended Personnel Platform GISO, §5004(d)
Operator Certification, Mobile & Tower Cranes GISO, §5006.1   
Operator Qualifications GISO, §5006
Operating Practices GISO, §5008
Outriggers, use of GISO, §4994(b)
Overhead Loads  GISO, §5002
Refueling GISO, §4998
Riding loads Prohibited GISO, §4995
Rigging by Qualified Person (Rigger) GISO, §4999(a)
Side-boom Cranes, Subject to CSO  CSO, §1694
Signal Requirements GISO, §5001
Hand Signals, Cranes GISO, §5001, Plate I
Hand Signals, Boom Equipments GISO, §5001, Plate I
Swing (Rotation)  GISO, §4993
Suspended Personnel Platform GISO, §5004(d)
Travel  GISO, §4991
Accident Avoidance, During Travel GISO, §4991(a)
Empty Hook, Block, Restraining / Securing During Travel GISO, §4991(b)
Industrial Tow Tractors GISO, §3664   
Laundry & Dry Cleaning  GISO, §4494
Forklifts/Industrial Trucks  GISO, §3650(t)
Posting of GISO, §3664   
Tree Work, Maintenance & Removal  GISO, §3428
OPERATOR CAB, Cranes, Hoists GISO, §4925
Access to GISO, §4926
Overhead Protection GISO, §4925(a)
OPERATOR CAB, Truck, Protection GISO, §3705
OPERATOR CERTIFICATION, Mobile & Tower Cranes
Certifying Entities GISO, §5006.1(c)
Exception from Certification GISO, §5006.1(f) Exception 1-3
Operator Certification GISO, §5006.1(b)
Operator Qualifications GISO, §5006.1(a)
Physical Exam GISO, §5006.1(a)(1)
Re-Certification GISO, §5006.1(d)
Testing GISO, §5006.1(a)
Substance Abuse Test GISO, §5006.1(a)(2)
Written Exam GISO, §5006.1(a)(3)
Testing GISO, §5006.1(a)
Trainee Operation of Cranes GISO, §5006.1(e)
ORCHARD MAN-LIFTS (Pruning Towers) GISO, §3641
ORDERLY, NEAT, Electrical Boxes, Cabinets, etc. shall be closed, High Voltage ESO-HV, §2714(c) 
ORDERLY, Work Space GISO, §3362(a)
ORE PASSES & CHUTES, per MSO  MSO, §7052 
ORGANS, Electric, Grounding of, Cord Connected ESO-LV, §2395.45
 Grounding of, Permanently Wired or Fixed in Place ESO-LV, §2395.42
OSHA 300 LOG, Form 300, 300A & 301 See CCR, Title 8, Chapter 7, §14300.29
OSMIUM TETROXIDE, Airborne Contaminant, Exposure limit GISO, §5155, & Appx A
Listed, Permissible Exposure Limits GISO, §5155, Table AC-1
Process safety management for acutely hazardous substances  GISO, §5189, Appx A
OUTDOOR ADVERTIZING STRUCTURES  GISO, Article 11
Fall Protection Requirements GISO, §3416
General  GISO, §3412
Ladder Scaffolds GISO, §3414
Ladders  GISO, §3413
Poster Ladder Scaffolds GISO, §3414
Suspended Scaffolds GISO, §3415
OUTDOOR LAMPS  ESO-LV, §2375.25 
OUTDOOR WIRING, High Voltage ESO-HV, Article 19
Circuit Feedback ESO-HV, §2831
General Requirements ESO-HV, §2823
Insulated Conductors ESO-HV, §2830
Outdoor Lighting ESO-HV, §2825
Overhead Lines ESO-HV, §2824
Raceways Above Ground  ESO-HV, §2826
Raceways (or Ducts) Below Ground  ESO-HV, §2827
Risers ESO-HV, §2828
Terminal Enclosures ESO-HV, §2829
OUTDOOR WIRING, Low Voltage ESO-LV, Article 8
Application / Scope ESO-LV, §2375.1
Clearance from Buildings ESO-LV, §2375.19
Clearance from Ground ESO-LV, §2375.18
Conductors on Poles ESO-LV, §2375.7
Location of Outdoor Lamps  ESO-LV, §2375.25
OUTLET DEVICES ESO-LV, §2360.4
OUTLINE LIGHTING, & Electrical Signs 
High Voltage ESO-HV, Article 39
Electric-Discharge Tubing  ESO-HV, §2972
Electric Discharge Tubing, Terminals & Receptacles ESO-HV, §2973
Installation of Conductors ESO-HV, §2970
Switches on Doors ESO-HV, §2974
Transformers ESO-HV, §2971
Low Voltage ESO-LV, Article 73
Clearances ESO-LV, §2560.10
Disconnecting Means ESO-LV, §2560.2
Location of  ESO-LV, §2560.3
OUTRIGGER BEAMS, Suspending Window Cleaning Scaffolding    GISO, §3291(d)
OUTRIGGER SCAFFOLDS  CSO, §1645 
”           ”           ”           ”           ” See also under SCAFFOLDS 
OUTRIGGERS, Cranes    GISO, §4994(b)
OVENS, Bakery GISO, §4530
OVENS & RANGES See APPLIANCES 
OVERBURDEN, per MSO MSO, §6986
OVER-CURRENT PROTECTION, Electrical  ESO-LV, Article 10
”           ”           ”           ”           ” See also ELECTRICAL INTERRUPTING DEVICES 
”           ”           ”           ”           ” See also ELECTRICAL DISCONNECTION MEANS / CUTOUTS
”           ”           ”           ”           ” See also ELECTRICAL CIRCUIT BREAKERS
Arcing or Suddenly Moving Parts ESO-LV, §2390.41
Circuit Breakers ESO-LV, §2390.81
Circuit Breakers Used as Switches ESO-LV, §2390.81(c)
Disconnecting Means for Fuses ESO-LV, §2390.20
Fuses See also under FUSES
Panelboards
Installation on load side of switches ESO-LV, §2484.19
Safe location ESO-LV, §2340.27
General Requirements ESO-LV, §2390.1
Grounded Conductors ESO-LV, §2390.10
Location of Devices, Accessible / Protected ESO-LV, §2390.24
OVERFLOW & SPILLS, control of GISO, §5163
OVERHEAD CONDUCTORS, Energized, Guarding against Accidental Contact ESO-LV, §2320.1(b)
OVERHEAD POWER LINES, Accidents Prevention  ESO-HV, Article 37
General Provisions for ESO-HV, §2946
Notification to the Operators of High-Voltage Lines ESO-HV, §2948
Responsibility for Safeguards  ESO-HV, §2948
Special Exemption ESO-HV, §2949
Warning Signs Requirement ESO-HV, §2947
OVERHEAD LINES, per TelSO See TRANSMISSION LINES, Overhead
Approach Distances to High Voltage Lines TelSO, §8602(h)
OVERHEAD LOADS, Hoisting of    GISO, §5002
Safety Type Hook Requirement    GISO, §5002
Working beneath suspended load prohibited GISO, §5002, Note
OVERHEAD PROTECTION, Operator Cab
Cranes, Boom Type Mobile Cranes GISO, §4925(a)
Trucks, Protection from Shifting Loads GISO, §3705
OVERHEAD SPACE REQUIREMENTS GISO, §3224
OVERHEATING, Protection of Equipment ESO-LV, §2340.13
    ”            ”           ”           ”           ”     ESO-HV, §2710.1(b)
OVERLOADING, of Buildings / Structures, During Erecting & Construction     CSO, §1709(a)
OVER-SPEED PROTECTION, Engines
Emergency Stop Device, Oil & Gas Drilling Equipment PSO-D&P, §6625 
Emergency Stop Device, Air and Gas Compressors, Oil & Gas Drilling Equipment PSO-D&P, §6554(h)
Emergency Stop Device, Emergency Stop Device, Air and Gas Compressors, Refineries PSO-R,T&H, §6874(f)
General Over-Speed Protection Requirement GISO, §3511
OWNERSHIP of PPE, Employer’s Responsibility, Irrespective of     GISO, §3380(d)
OWNERSHIP of TOOLS, Employer’s Responsibility, Irrespective of     GISO, §3556(a)
OXALIC ACID, Airborne Contaminant, Exposure limit GISO, §5155, & Appx A
Listed, Permissible Exposure Limits GISO, §5155, Table AC-1
OXIDE, ETHYLENE (ETO)  GISO, §5220
”           ”      ”                    See Also CARCINOGENS, Regulated
Application & Scope GISO, §5220(a)  
Definitions GISO, §5220(b)  
Appendices, Application of GISO, §5220(n)  
Communication of Hazards GISO, §5220(j)  
Information & Training  GISO, §5220(j)(3)
Material Safety Data Sheets GISO, §5220(j)(2) 
Signs & Labels  GISO, §5220(j)(1)
Emergency Situations  GISO, §5220(h)  
Exposure Limit (PEL)  GISO, §5220(c) 
Permissible Exposure Limit (PEL)  GISO, §5220(c)(1)
Short Term Exposure Limit (STEL)  GISO, §5220(c)(2) 
Exposure Monitoring  GISO, §5220(d)  
Material Safety Data Sheets GISO, §5220(j)(2) 
Medical Surveillance  GISO, §5220(i)  
Methods of Compliance  GISO, §5220(f)  
Notification of Use & Emergencies GISO, §5220(m)  
Observation of Monitoring GISO, §5220(l)  
Employee Observation  GISO, §5220(l)(1)
Observation Procedures  GISO, §5220(l)(2) 
Personal Protective Equipment  GISO, §5220(g)  
Respiratory Protection GISO, §5220(g)  
Regulated Areas  GISO, §5220(e)  
Record keeping  GISO, §5220(k)  
Availability of Records GISO, §5220(k)(4)
Exposure Measurements  GISO, §5220(k)(2) 
Medical Surveillance  GISO, §5220(k)(3)
Objective Data For Exempted Operations  GISO, §5220(k)(1)
Transfer of Records  GISO, §5220(k)(5)
Signs & Labels  GISO, §5220(j)(1)
Training  GISO, §5220(j)(3)
OXIDE, NITROUS, Haz-Com     See also Hazard Communication GISO, §5194
OXYDIZERS, Overflow & Spill Control GISO, §5163(c)
OXYGEN GISO, Article 139
  ”         ” See also FLAMMABLE LIQUIDS, GASES & VAPORS
Bulk oxygen systems 
Consumer sites  GISO, §5500
Distance between Bulk Oxygen Systems & Exposures GISO, §5502
Equipment Assembly & Installation GISO, §5507
Installation & Equipment Assembly  GISO, §5507
Liquid Oxygen Vaporizers GISO, §5506
Location of Bulk Oxygen Systems GISO, §5501
Maintenance  GISO, §5509
Operating instructions  GISO, §5508
Piping, Tubing & Fittings GISO, §5504
Safety Relief Devices GISO, §5505
Storage, Bulk Oxygen Storage Containers GISO, §5503
Compressed oxygen
Limitation on use  CSO, §1743
Misuse  GISO, §3305
Cylinders  CSO, §1743
Handling  CSO, §1740
Pressure-reducing device required  CSO, §1743
Storage  CSO, §1740
Device allowing mixture of gas and oxygen approval  CSO, §1743(a)
Hoses & Connections CSO, §1742
Liquid oxygen vaporizers  GISO, §5506
Manifold, Hoses & Connections CSO, §1742(e)
OXYGEN / ACETYLENE, Cylinders & Containers     GISO, §4650(d)
Storage and Use of, per CSO CSO, §1740(g)
OXYGEN, in Breathing Air 
Content GISO, §5144(i)(1)
Deficiency GISO, §5149
Mining Operations  GISO, §7098(e)
Quality Standard & Specifications GISO, §5144(i)(1)
Tunneling Operations  GISO, §8437(e), (f)
OXYGEN DIFLUORIDE, Airborne Contaminant, Exposure limit GISO, §5155, & Appx A
Listed, Permissible Exposure Limits GISO, §5155, Table AC-1
Process safety management GISO, §5189, Appx A
OXYGEN, Liquid   See Also OXYGEN GISO, §5501(c)
Liquid Oxygen Vaporizers GISO, §5506
OXYGEN, Misuse Prohibited    GISO, §3305
OXYGEN, Stored Near Combustible Material Prohibited     GISO, §4650(d)
OXYGEN, Welding Backflow Protector  GISO, §4845(b)
OXYGEN, Misuse of Compressed Oxygen  GISO, §3305