Does "Subpart S - Electrical" Apply to You?

Subpart S provides the electrical standards that address the practical safeguarding of employees in the workplace. According to the standard on introduction, this subpart has two distinct sections: 

  • Section One - Design safety standards for electrical systems
    • Design safety standards for electric utilization systems (Includes all electric equipment and installations used to provide electric power and light for employee workplaces)
    • Specific purpose equipment and installations
    • Hazardous (classified) locations
    • Special systems (over 600 volts)
  • Section Two - Safety-related work practices

Do you have buildings, structures and other premises that have electrical installations and utilization equipment? Do you have specific purpose equipment or installations (i.e., x-ray equipment, electric welders, cranes, hoists, carnival, electric signs)? Do you have hazardous locations (i.e., service stations, aircraft hangars, marinas, chemical processing plants)? Do you have systems operating at over 600 volts (i.e., communication systems, fire alarm systems)? Do you have employees that work on or near electrical hazards and/or may be exposed to electrical hazards?  If you said yes to any of these questions, click on the applicable tabs below to see how they apply to you.

This subpart also contains definitions related to the standards such as: 

Competent person - One who is capable of identifying existing and predictable hazards in the surroundings or working conditions that are unsanitary, hazardous, or dangerous to employees and who has authorization to take prompt corrective measures to eliminate them.

Qualified person - One who has received training in and has demonstrated skills and knowledge in the construction and operation of electric equipment and installations and the hazards involved.

Subpart S - Electrical

Tab/Accordion Items

If yes, then you need to comply with the standard on electric utilization systems along with the other standards listed below. This standard applies to buildings, structures and other premises that have electrical installations and utilization equipment installed or used within them, so this should be yes for most employers. This includes:

  • Yards;
  • Carnivals;
  • Parking and other lots; 
  • Mobile homes; 
  • Recreational vehicles; 
  • Industrial substations; 
  • Conductors that connect the installations to a supply of electricity; and
  • Other outside conductors on the premises.

The design safety standards do not apply to:

  • Installations in ships, watercraft, railway rolling stock, aircraft, or automotive vehicles other than mobile homes and recreational vehicles; 
  • Installations underground in mines; 
  • Installations of railways for generation, transformation, transmission, or distribution of power used exclusively for operation of rolling stock or installations used exclusively for signaling and communication purposes; 
  • Installations of communication equipment under the exclusive control of communication utilities, located outdoors or in building spaces used exclusively for such installations;
  • Installations under the exclusive control of electric utilities for the purpose of communication or metering; or
  • Generation, control, transformation, transmission, and distribution of electric energy located in buildings used exclusively by utilities for such purposes or located outdoors on property owned or leased by the utility or on public highways, streets, roads, etc., or outdoors by established rights on private property.

Note: According to paragraph (b) of the electric utilization systems standard, some requirements of the following standards do not apply based on installation dates: generalwiring design and protection; wiring methods, components, and equipment for general use; specific purpose equipment and installations; hazardous locations; and special systems. Reference paragraph (b) for more information. 

This section of the subpart also contains the standard, general (general requirements), that pertains to examination, installation, and use of equipment; electrical connections; arcing parts; marking; disconnecting means and circuits; 600 volts, nominal or less (i.e., work space, guarding); over 600 volts, nominal (i.e., enclosures, entrance, exits, illumination); and other general requirements.

The wiring design and protection standard provides additional requirements pertaining to use and identification of grounded and grounding conductors; branch circuits (i.e., ground fault circuit interrupters, competent person); outside conductors, 600 volts, nominal or less; location of outdoor lamps; services (i.e., disconnecting means); overcurrent protection; and grounding (i.e., generators, connections). 

Lastly, the standard on wiring methods, components, and equipment for general use provides requirements pertaining to wiring methods (i.e., temporary wiring, cable trays, open wiring on insulators); cabinets, boxes, and fittings (i.e., conductors, covers, canopies, junction boxes); switches; switchboards and panelboards; enclosures for damp or wet locations; conductors for general wiring; flexible cords and cables;  portable cables over 600 volts, nominal; fixture wires; and equipment for general use (i.e., lighting fixtures, lampholders, lamps, receptacles, appliances, motors, batteries).

Additional information can be found on the safety and health topic pages for electrical safety, lockout/tagout, illumination and personal protective equipment.

Do you have any of the following or similar installations: electric signs, outline lighting, hoists, cranes, elevators, dumbwaiters, escalators, moving walks, wheelchair lifts, stairway chair lifts, electric welders, information technology equipment, x-ray equipment, induction heating equipment, dielectric heating equipment, electrolytic cells (i.e., electrolytic cell lines, process power supply for the production of aluminum, cadmium, chlorine, copper, fluorine, hydrogen peroxide, magnesium, sodium, sodium chlorate and zinc), irrigation machines (i.e., electrically driven or controlled), swimming pools, fountains, carnivals, fairs, and/or circuses? If yes, then you also need to comply with the standard on specific purpose equipment and installations.

This standard includes specific requirements for the equipment and installations listed above (or similar in nature) pertaining to disconnecting means, location, switches, operation, control panels, signs, identification, guarding and grounding, remote control, portable electric equipment, power supply circuits, receptacles, lighting fixtures, ceiling fans, cord and plug-connected equipment, distribution boxes, and termination boxes.

Additional information can be found on the safety and health topic pages for electrical safety, lockout/tagoutflammable liquids and personal protective equipment.

Do you have any of the following or similar occupancy: aircraft hangars, gasoline dispensing and service stations, bulk storage plants for gasoline or other volatile flammable liquids, paint-finishing process plants, health care facilities, agricultural or other facilities where excessive combustible dusts may be present, marinas, boat yards, or petroleum and chemical processing plants?

If yes, then you also need to comply with the standard on hazardous (classified) locations. It covers electric equipment and wiring that are classified depending on the properties of the flammable vapors, liquids or gases, or combustible dusts or fibers that may be present and the likelihood that a flammable or combustible concentration or quantity is present. This standard provides the requirements pertaining to classifications (i.e., class 1, division 1), documentation, electrical installations, conduits, equipment in division 2 locations, protection techniques (i.e., explosion proof apparatus, dust ignition proof, purged and pressurized), and class 1, zone 0, 1, and 2 locations.  

Additional information can be found on the safety and health topic pages for electrical safety, lockout/tagoutflammable liquidscombustible dust and personal protective equipment. Also reference SN 09 - Determining Hazardous (Classified) Locations in Unventilated Pits or Depressions Below Grade in Commercial Garages and and SN 10 - Requirements for Portable Lamps in Vehicle Service Garages.

If yes, then you also need to comply with the standard on special systems. It contains the general requirements for all circuits and equipment operated at over 600 volts pertaining to aboveground wiring methods, insulation shielding, moisture or mechanical protection for metal-sheathed cables, interrupting and isolating devices, mobile and portable equipment, and tunnel installations. It also provides specific requirements for emergency power systems (i.e., signs); class 1, class 2, and class 3 remote control, signaling, and power-limited circuits; fire alarm systems; communication systems; solar photovoltaic systems; and integrated electrical systems.

Additional information can be found on the safety and health topic pages for electrical safety, lockout/tagout and personal protective equipment.

If yes, you need to comply with this section of the standard. According to the scope, this section covers electrical safety-related work practices for both qualified and unqualified persons working on, near, or with the following installations:

  • Premises wiring: Installations of electric conductors and equipment within or on buildings or other structures, and on other premises such as yards, carnival, parking, and other lots, and industrial substations;
  • Wiring for connection to supply: Installations of conductors that connect to the supply of electricity; and
  • Other wiring: Installations of other outside conductors on the premises; installations of optical fiber cable where such installations are made along with electric conductors.

Qualified persons are those who have training in avoiding the electrical hazards of working on or near exposed energized parts.

Unqualified persons those with little or no such training working on or near exposed energized parts.

This section does not apply to:

  • Generation, transmission, and distribution installations (reference the standard on electric power generation, transmission, and distribution);
  • Installations of communication equipment (reference the standard on telecommunications);
  • Installations in ships, watercraft, railway rolling stock, aircraft, or automotive vehicles other than mobile homes and recreational vehicles; or
  • Installations of railways for generation, transformation, transmission, or distribution of power used exclusively for operation of rolling stock or installations of railways used exclusively for signaling and communication purposes.

This section of subpart S provides training requirements for the employees who face a risk of electric shock that is not reduced to a safe level by the electrical installation requirements provided in the first section of this subpart. The training requirements for training content including safety-related work practices, skills to distinguish exposed live parts, determining the nominal voltage of exposed live parts, clearance distances, and type of training (i.e., classroom or on-the-job) determined by the risk to the employee.  

It also provides selection and use of work practices standard which applies to work on or near exposed energized and deenergized parts that expose the employee to electrical hazards. This standard provides requirements for safety-related work practices, working on or near exposed deenergized parts (i.e., application of locks and tags, deenergizing equipment, reenergizing equipment), and working on or near exposed energized parts (i.e., overhead lines, vehicular and mechanical equipment, illumination, confined spaces, portable ladders, housekeeping duties, interlocks).

The standard on use of equipment applies to the use of cord and plug connected equipment, including flexible cord sets (extension cords) and provides requirements pertaining to handling portable electric equipment (i.e., inspections, grounding type equipment, conductive work locations), electric power and lighting circuits (i.e., routine opening and closing circuits, overcurrent protection modification), test instruments and equipment (i.e., use, inspections, rating of equipment, use of flammable or ignitable materials). 

The safeguards for personnel protection standard provides additional requirements for employee protection including use of personal protective equipment (reference subpart I - personal protective equipment), and protective equipment and tools (i.e., insulating tools or handling equipment, fuse handling equipment, alerting techniques, safety signs and tags, barricades, attendants). 

Additional information can be found on the safety and health topic pages for electrical safety, lockout/tagoutconfined spaceswalking and working surfaces and personal protective equipment.