| Publisher | US Department of Labor, OSHA |
|---|---|
| Type | Regulation (US federal) |
| Scope | Electrical safety requirements for general industry workplaces, covering both the design and installation of electrical systems and the safety-related work practices of employees. |
| Who uses it | US general industry employers, safety and compliance managers, electrical workers, facility engineers and OSHA compliance officers. |
| Edition note | Codified in Title 29 of the Code of Federal Regulations. Refer to OSHA or the electronic CFR for the current text. |
What It Is
Subpart S of 29 CFR Part 1910 is the section of the federal Occupational Safety and Health Administration rules that addresses electrical hazards in general industry. It spans sections 1910.301 through 1910.399 and is divided into groups. The design safety standards (1910.302 through 1910.308) address how electrical equipment and wiring must be installed, including general requirements, wiring design and protection, wiring methods, specific equipment, hazardous (classified) locations and special systems. The safety-related work practices (1910.331 through 1910.335) address what employees and employers must do when working on or near electrical equipment. Definitions are in 1910.399.
The installation provisions draw heavily on the language and concepts of the National Electrical Code but are written as regulation. The work practice provisions address training, selection and use of work practices, use of equipment and safeguards for personnel protection, including protective equipment and alerting techniques. Section 1910.333, for example, sets the basic rule that exposed live parts should be de-energized before work unless doing so creates greater hazards or is infeasible.
Why It Matters
Unlike consensus standards, OSHA rules are federal law in the United States. Employers covered by the Occupational Safety and Health Act must comply, and violations can result in citations and penalties. States with OSHA-approved State Plans enforce requirements that must be at least as effective as the federal rules, and some are more stringent.
Because the work practice rules are written in performance terms, they tell employers what outcome to achieve but not always how. That is why NFPA 70E is so frequently used alongside Subpart S: it supplies the detailed methods, such as approach boundaries and arc flash risk assessment, that help an employer demonstrate that the federal requirements are met.
Key Concepts
- Design safety standards — requirements for electrical installations and equipment, such as guarding of live parts, working space, grounding and overcurrent protection.
- Safety-related work practices — rules for employee behavior and employer controls when working on or near exposed energized parts.
- Qualified and unqualified persons — Subpart S distinguishes between workers trained to work on or near exposed energized parts and those who are not, with different training and approach expectations.
- De-energizing as the default — work on exposed live parts is expected to be performed de-energized unless the employer can show greater hazard or infeasibility.
- Lockout and tagging — Subpart S contains electrical-specific lockout and tagging provisions that work alongside the general control of hazardous energy rule in 1910.147.
- Protective equipment and alerting — employers must provide suitable protective equipment, insulated tools and barricades, signs or attendants to warn and protect employees.
- Hazardous (classified) locations — section 1910.307 addresses equipment in locations where flammable gases, vapors, dusts or fibers may be present.
Who Should Know It
- EHS and compliance managers responsible for OSHA programs
- Electricians and maintenance technicians in manufacturing and commercial facilities
- Facility and plant engineers approving installations and modifications
- Supervisors who assign electrical tasks and verify qualifications
- Trainers who deliver qualified and unqualified worker training
Related Standards
- NFPA 70E — the consensus standard commonly used to meet Subpart S performance requirements in practice.
- OSHA 29 CFR 1910.269 — the parallel OSHA rule for electric power generation, transmission and distribution work.
- NFPA 70 (NEC) — the installation code on which much of the Subpart S design content is based.
- NEC Articles 500-506 — provide the detailed hazardous location framework reflected in 1910.307.
How ASEEE Uses It
ASEEE electrical safety programs map learning outcomes and assessments to the requirements of Subpart S, especially the safety-related work practices, so that candidates understand both the legal obligation and the practical methods used to satisfy it. See related ASEEE programs.
ASEEE Programs Referencing This Standard
- Arc Flash Hazard Analysis and Risk Assessment
- Competent Electrical Person
- Electrical Control Person
- Electrical QA/QC Inspector
- Electrical Safety Rules: Regulations, Hazards and Risk Assessment
- VLF AC Hipot Testing of HV Cables
Educational summary only. ASEEE is not the publisher of this document and this page does not reproduce or replace it. Always consult the current official edition from OSHA (US Department of Labor) for requirements.