The Importance of an Arc Flash Hazard Analysis and Proper PPE

In industrial environments where electricity is essential to daily operations, the potential for arc flash incidents is a constant concern.  An arc flash, defined by NFPA 70E as an unexpected release of heat and light energy due to electricity passing through the air, poses grave dangers to personnel and equipment. The consequences can be catastrophic, ranging from severe burns to fatalities.

Arc flash incidents can be triggered by various factors, including dust, dropped tools, accidental contact, and equipment failure, among others. When an arc flash occurs, temperatures at the point of the arc can skyrocket to over 35,000 degrees Fahrenheit, unleashing a torrent of heat, light, and sound waves. The effects are swift and devastating, often resulting in severe injuries and irreversible damage.

An arc flash hazard analysis is a comprehensive assessment aimed at identifying potential risks associated with arc flash incidents in a particular work environment. This analysis involves key steps to accurately evaluate the hazards and determine the appropriate safety measures to mitigate them.

The first step in conducting an arc flash hazard analysis is to gather relevant data and information about the electrical systems and equipment present in the facility. This includes obtaining electrical drawings, equipment specifications, and maintenance records.

A thorough assessment of the electrical system is conducted to identify potential arc flash hazards. This involves examining the configuration of the electrical system, including the types of equipment, voltage levels, and potential fault currents.

A short circuit analysis is performed to calculate the potential fault currents that could occur in the electrical system. This analysis helps determine the magnitude of energy that could be released in the event of an arc flash.

A protective device coordination study is conducted to evaluate the performance of protective devices such as circuit breakers and fuses. This study ensures that protective devices operate correctly to isolate faults and minimize the risk of arc flash incidents.

Using the data obtained from the short circuit analysis and protective device coordination study, arc flash hazard calculations are performed to determine the incident energy levels at various points in the electrical system. Incident energy is measured in calories per square centimeter (cal/cm²) and represents the thermal energy released during an arc flash event.

Based on the calculated incident energy levels, the arc flash boundary is determined. The arc flash boundary is the distance from the arc flash source within which a person could be exposed to a second-degree burn if an arc flash were to occur.

The final step in the arc flash hazard analysis involves selecting appropriate PPE based on the calculated incident energy levels and arc flash boundary. PPE selection typically includes flame-resistant clothing, face shields, gloves, and other protective gear designed to minimize the risk of injury during an arc flash event. A comprehensive approach to PPE entails head-to-toe protection, considering the various ways in which individuals may be exposed to the dangers of an arc flash.

  • Head Protection: Hard hats are essential to shield the head from falling debris and impact during an arc flash event.
  • Facial Protection: Face shields provide a barrier against the intense heat and light emitted during an arc flash, safeguarding the eyes and face from burns and injuries.
  • Hearing Protection: Given the deafening noise generated by arc flash incidents, proper hearing protection is crucial to prevent hearing loss.
  • Hand Protection: Insulated gloves are imperative to protect hands from the heat and electrical currents associated with arc flash events.
  • Foot Protection: Closed-toe shoes offer essential protection against electrical currents and heat exposure, minimizing the risk of foot injuries.
  • Full Body Coverage: Ensuring that all parts of the body are adequately covered further reduces the risk of burns and other injuries.

In addition to standard PPE, wearing flame-resistant (FR) clothing is highly recommended in environments where arc flash hazards exist. However, simply donning FR clothing is not enough; proper use and fit are equally crucial to ensure maximum protection.

  • FR clothing should be fully buttoned up, with sleeves rolled down to prevent exposure of skin to the hazards of an arc flash.
  • Clothing should provide a comfortable yet non-constricting fit, allowing for a range of motion while maintaining a protective layer of air between the fabric and the skin.
  • Shirts should be securely tucked into pants to prevent arc flash incidents from reaching exposed skin.

Employers bear the responsibility of ensuring the safety of their workers in environments prone to arc flash incidents. Conducting an arc flash hazard analysis is essential to identify potential risks and determine the appropriate PPE needed to mitigate them. This analysis enables employers to implement robust safety measures and provide comprehensive training to employees on the use of PPE in hazardous environments.

Once the arc flash hazard analysis is complete, documentation of the findings and recommendations is prepared. Additionally, training is provided to employees to ensure they understand the hazards associated with arc flash incidents and how to properly use the recommended PPE.  By following these steps, an arc flash hazard analysis helps organizations identify and mitigate risks associated with arc flash incidents, ultimately enhancing workplace safety and protecting employees from potential harm.

If you’re seeking assistance with arc flash hazard analysis or need guidance on PPE selection, contact IFO Group at 832-403-2135 or at info@ifogroup.com for a free consultation.