Safety Resource Center

What you Need to Know About Arc Flash

Written by RitzSafety | Apr 5, 2021 7:45:18 PM

What is an Arc Flash?

  • Arc flash is due to an arcing fault
  • Rapid release of energy (explosion)
  • Massive pressure - exceeding 100s - 1,000 Ibs/ft2
  • Sounds can exceed 160 dB
  • Material & molten metal expelled at speeds exceeding 700 mph
  • Temps. in excess of 30,000 degrees F

It's clear that arc flashes can be a very real danger in the workplace, which is why there are standards to keep workers safe. 

An employer's responsibilities are outlined by ANSI, NFPA and OSHA:

  1. Conduct an Arc Flash Safety Study & Hazard Risk Assessment to identify potential hazards
  2. Engineer out potential hazards
  3. Provide the appropriate PPE for hazards that cannot be eliminated
  4. Educate employees on potential hazards and the use of PPE

There are multiple electrical safety standards that employers should know:

  1. NFPA 70E: Electrical Safety in the Workplace. The purpose is to provide a practical, safe workplace relative to the hazards associated with electrical energy. This acts as a guide to avoiding injuries and assists users in complying with OSHA.
  2. OSHA 1910.269 and 1926 Subpart V: Arc Flash Law for Power Generation; Transmission, Distribution
  3. ASTM F1506: Performance Standard for Arc Related Fabrics
  4. ASTM D6413: Test Method: Flame Resistance "Vertical Flame Test"
  5. ASTM F1959: Test Method: Arc Rating Fabrics
  6. ASTM F2178: Test Method: Arc Rating Eye & Face Protection

Determining AF Protection:

  1. 70E Tables: Minimum protection requirements
  2. Calculations: Incident energy determined (arc rating)

FR versus AR
FR (or Flame Resistant):

  • Tested per ASTM D6413 Vertical Flame
  • Self extinguishes within 2 sec. or less
  • Does not melt or drip
  • Has a char length of 6" or less

AR (or Arc Rated):

  • Must be rated as Arc Resistant per ASTM F1506
  • Includes Vertical Flame Test
  • Also includes ASTM F1959 to determine arc rating

An Arc Rating is a measurement of a fabric's ability to protect the wearer from second-degree burns. All arc rated fabrics are flame resistant, but not all flame resistant fabrics are arc rated!

Task Based vs. Daily Wear

 

Layering for Protection

  • In arc flash, 1 + 1 ≠ 2
  • Layered combinations must be arc tested together
  • Most importantly, you need proof

Different types of PPE must meet the requirements of different ASTM specifications in order to be labeled as AR (Arc Rated)

     • Clothing – ASTM F1506
     • Rainwear – ASTM F1891
     • Face protective products & hoods – ASTM F2178
     • Arc Protective Blankets – ASTM F2676 

Remember, a hazard risk assessment needs to be performed in order to fully understand your specific hazard and the protection it requires.

Ritz Safety, a family-owned business since 1983, is here to serve you. Our 13 sales and distribution centers across the United States provide a wide array of PPE and safety solutions, promoting all workers' health, well-being, and protection. Contact us at sales@ritzsafety.com or 800-451-3077 for convenient, cost-effective, and customized warehouse industry PPE solutions.