The Different Arc Flash PPE Categories Explained

Arc flashes are intense electrical explosions that can result in severe harm to employees and company infrastructure. To help protect those who work with electrical equipment, companies can enforce employees to wear PPE while on the job. Which PPE is appropriate, however, depends on the type of equipment at hand.

The National Fire Protection Association has made maximizing electrical safety easier by creating the standard NFPA 70E. It’s titled the Standard for Electrical Safety in the Workplace and outlines electrical safety requirements and practices for employees. In this standard, the NFPA distinguishes proper PPE into four separate categories. Here, Dreiym Engineering dives into the different Arc Flash PPE categories explained.

Please note that each Arc Rating value refers to the incident energy per material or layers of materials and is expressed in cal/cm². PPE manufacturers must uphold the minimum Arc Rating for their PPE to fall within that category.

Category 1: Minimum Arc Rating 4 cal/cm²

This category requires a single layer of arc-rated PPE for workers. A few examples of protective materials employees must wear include:

• Hard hat
• Safety goggles and an arc-rated face shield
• Hearing protection
• Leather gloves
• Arc-rated long-sleeve shirt and long pants
• Leather footwear

Category 2: Minimum Arc Rating 8 cal/cm²

• Arc-rated Flash Suit Hood or AR Face Shield
• Safety goggles or glasses
• Hearing protection
• Leather gloves
• Arc-rated long-sleeve shirt and long pants or coveralls
• Arc-rated Sock hood or balaclava
• Arc-rated jacket
• Leather footwear

Category 3: Minimum Arc Rating 25 cal/cm²

• Arc-rated Flash Suit Jacket and AR pants or coveralls
• Arc-rated Flash Suit hood or balaclava
• Rubber insulating gloves and leather protectors or arc-rated gloves
• Hearing protection
• Arc-rated long-sleeve shirt
• Leather footwear

Category 4: Minimum Arc Rating 40 cal/cm²

The last of the different Arc Flash PPE categories is Arc Flash PPE category 4. Arc Flash PPE category 4 requires the most layers of protective gear. Each piece of clothing must have a minimum rating of 40 cal/cm². Someone working in this category of PPE is likely to be seen in the following items.

• Hard hat and arc-rated Flash Suit Hood
• Safety glasses or goggles
• Hearing protection
• Rubber insulating gloves and leather protectors or arc-rated gloves
• Arc-rated Flash Suit Jacket and AR pants or coveralls
• Leather footwear

How To Know if Your Workplace Is Susceptible to an Arc Flash

To assess the electrical hazards in your workplace, invest in an Arc Flash study. At Dreiym Engineering, our team of Arc Flash consultants can determine the risk of an Arc Flash happening at your facility and what kind of damage to expect in a worst-case scenario. Contact us today to schedule a detailed site walk-down, which is the first step to upkeeping the electrical safety and quality of your company.