1. Introduction

Electrical hazards (shock, arc flash, arc blast, electrocution) are a leading cause of workplace injuries and fatalities.
To control these hazards:

• OSHA Subpart S (29 CFR 1910.301–399) establishes legal requirements for electrical safety in general industry.

• NFPA 70E (Standard for Electrical Safety in the Workplace) provides detailed work practices, procedures, and PPE requirements to help employers comply with OSHA.

2. OSHA Subpart S – Key Requirements

OSHA Subpart S covers electrical safety in the workplace.
Main parts include:

• 1910.301 – 1910.308: Design safety standards for electrical systems.

• 1910.331 – 1910.335: Safety-related work practices.

• 1910.399: Definitions.

🔑 Major Requirements:

1. Training (1910.332):

   • Qualified vs. unqualified workers.

   • Workers must be trained to identify and avoid electrical hazards.

2. Work Practices (1910.333):

   • De-energize equipment before work.

   • If live work is necessary → follow safe procedures and PPE use.

3. Lockout/Tagout (LOTO) (1910.333(b)):

   • De-energize circuits before maintenance.

   • Apply locks/tags to prevent accidental re-energization.

4. Use of Equipment (1910.334):

   • Inspect tools and cords before use.

   • Use GFCIs in damp/wet locations.

5. PPE (1910.335):

   • Proper use of insulating gloves, face shields, arc-rated clothing, etc.

3. NFPA 70E – Key Elements

NFPA 70E is not law, but OSHA references it as the recognized industry practice.

🔑 Main Chapters:

1. Chapter 1 – Safety-Related Work Practices

   • Establishing electrically safe work conditions.

   • Approach boundaries: Limited, Restricted, Arc Flash Boundary.

   • Energized electrical work permit (EEWP) requirements.

2. Chapter 2 – Safety-Related Maintenance

   • Ensures equipment is maintained to reduce hazards.

3. Chapter 3 – Safety Requirements for Special Equipment

   • Batteries, capacitors, power electronic equipment, etc.

4. Annexes (Informative)

   • Risk assessment examples, training requirements, PPE charts.

4. NFPA 70E & Arc Flash Protection

Arc flashes can reach 35,000°F and cause severe burns.
NFPA 70E provides a step-by-step process:

1. Arc Flash Risk Assessment

   • Determine incident energy levels (cal/cm²).

   • Define Arc Flash Boundary.

2. PPE Categories (Table 130.7(C)(15))

   • Category 1: Arc-rated shirt/pants, face shield.

   • Category 2: Adds arc-rated coveralls, balaclava.

   • Category 3: Arc suit, hood, gloves.

   • Category 4: Highest level, full protection up to 40 cal/cm².

3. Approach Boundaries

   • Limited Approach: Distance an unqualified worker must stay away.

   • Restricted Approach: Only qualified workers with PPE.

   • Arc Flash Boundary: Distance where incident energy = 1.2 cal/cm².

5. Employer Responsibilities

Employers must:
✅ Provide a written Electrical Safety Program.
✅ Train workers on electrical hazards.
✅ Maintain all electrical equipment per manufacturer & NFPA 70B.
✅ Perform arc flash risk assessments.
✅ Supply PPE and insulated tools.

6. Worker Responsibilities

Workers must:
⚡ Follow safe work practices.
⚡ Use PPE correctly.
⚡ Inspect tools before use.
⚡ Report hazards and unsafe conditions.
⚡ Never bypass lockout/tagout procedures.

7. Difference Between OSHA Subpart S & NFPA 70E