Understanding OSHA’S New Arc Flash Guidance
- Brian Hall & Jeff Kershner
- Feb 5
- 5 min read
Updated: Feb 13
On November 25, 2024, the Occupational Safety and Health Administration (OSHA) released new guidance on protecting employees from electric-arc flash hazards. The guidance is in the form of a multi-page document which is available by visiting the OSHA website
The guidance is in response to the alarming number of workers who have received severe injuries or fatalities due to the hazard of electric arcs. OSHA provides several statistics to illustrate their concerns.
The National Fire Protection Association NFPA estimates that five to ten arc flash explosions occur daily across the US.
Industrial Safety and Hygiene News states that more than 3,600 disabling electrical contact injuries occur each year.
What Does OSHA Guidance Mean?
It is important to understand that this document is not a new OSHA requirement. OSHA states in the introduction section that this document is not a standard revision or new regulation, and it creates no new legal obligations for employers. Furthermore, NFPA 70E has not been revised because of this OSHA guidance. This document provides guidance on how to use the current edition of NFPA 70E to reduce injuries and fatalities from electrical hazards.
Why are these accidents happening?
In the document OSHA points out a few common myths as a reason for many of these arc flash incidents.
Myth #1 De-energized does not mean electrically safe.
Just because you opened a disconnecting device and “de-energize" the equipment it is NOT safe to work on. I recall a recent OSHA accident report of a worker changing a light ballast. He turned off the power and verified it was off with his meter. However, he did not install a lock. Someone came along and restored the power. He was electrocuted on 277-volts. These types of failures also lead to many arc flash accidents.
This is what OSHA is trying to bring light to in this document. Electrical equipment must be placed in an Electrically Safe Condition as required by NFPA 70E 120.6 in the 2024 edition of the standard.
This means that the conductors and circuit parts that employees will work on shall be disconnected from their energized parts, locked and tagged, and tested with a meter to verify the absence of voltage. An electrically safe condition must be achieved before it can be considered in a state that is safe to perform work.
If you skip any of the steps, such as not locking out, or verifying the absence of voltage with a meter, the employee must consider the equipment to be in an energized state and must take additional protective measures such as wearing insulating gloves, arc flash gear, and obtaining an energized work permit before any work can proceed.
Myth #2 I can work with the power on.
Many workers and employers do not understand that energized work is simply not allowed. There are only a few circumstances where it is permitted. See OSHA 1910.333 (listed below) or NFPA 70E 110.2(B) which closely mirrors the OSHA requirements.
1910.333 Selection and use of work practices.
“Live parts to which an employee may be exposed shall be deenergized before the employee works on or near them, unless the employer can demonstrate that deenergizing introduces additional or increased hazards or is infeasible due to equipment design or operational limitations. Live parts that operate at less than 50 volts to ground need not be de-energized if there will be no increased exposure to electrical burns or to explosion due to electric arcs”.
Just to clarify you can troubleshoot with the power on. You can work on equipment energized at less than 50-volts with the power on, or if you can justify it by saying de-energizing would create a life safety issue. Other than that, the equipment must be placed in an electrically safe condition.
Unfortunately, many workers and employers simply are not aware of or do not abide by these requirements and perform work such as removing or installing circuit breakers, lifting and landing wires with the power on.
Energized work significantly increases the risk for arc flash and so workers must be protected with arc flash gear and other protective equipment. This becomes problematic because it can be very difficult to perform this type of work in an arc flash suit and rubber insulating gloves. Consequently, workers either don’t put it on or remove it and get themselves hurt. OSHA is making it clear that the work is required to be performed in a de-energized electrically safe state. If you don’t create an electrically safe condition PPE must be worn. It’s one or the other.
Myth #3 The voltage is low, so I am safe
Arc flashes can and do occur at voltages as low as 208-volts. Here again workers are not aware that lower voltages can create an arc flash. Consequently, they work with the power on, and or, do not protect themselves with arc flash gear. Simple tasks such as removing or installing covers from 120/208 breaker panels can be the catalyst for an arc flash. Any 3-phase electrical equipment is capable of producing an arc flash.
Arc flash hazards must be labeled
Sometimes accidents occur because the employer hasn’t had an arc flash risk assessment performed of their electrical equipment. Arc flash warning labels clearly indicate the presence of arc flash and shock hazards, making workers aware of the risks before they approach or interact with electrical equipment. If there isn’t a label present on the machine, workers may assume that there isn’t a potential for arc flash.
Regulations require assessing the workplace for hazards
OSHA stresses in the document that existing regulations require assessing the workplace for hazards including electric arcs. Although there are different methods for calculating arc flash potential, and OSHA does not recommend any specific method, an engineering analysis typically called an arc flash study is the most accurate and common for determining how large an electrical arc flash could be. An arc flash study is a vital component to any company’s safety program.
Workers must have and wear PPE
Common work clothing such as t-shirts and jeans are made from cotton. In an arc flash cotton clothing and ignites. The clothing stays on fire long after the arc flash has been extinguished, essentially becoming fuel for the fire. OSHA identifies that wearing arc rated clothing is essential to worker safety. OSHA does have very clear regulations that require employers to protect their workers from identified workplace hazards with PPE.
Workers shall be trained
OSHA states that only qualified workers are permitted to perform tasks such as testing and troubleshooting. Understanding what the regulator means by a qualified worker is important. This means more than just the technical ability to perform the task. Qualified workers must receive electrical safety training so they have the ability to identify hazards and take precautions that reduce or eliminate the risk. Does the worker know when arc flash gear is required to be put on? When is it safe to take off? Electrically safe training is required by OSHA 1910.332 https://www.osha.gov/laws-regs/regulations/standardnumber/1910/1910.332
Equipment must be maintained
OSHA states that arc flashes are more likely to occur when equipment isn’t properly maintained. The risk increases if the equipment has worn or damaged insulation, loose contacts, impurities like dust or moisture are allowed to build up inside of the equipment.Following industry standards for equipment maintenance such as NFPA 70B can significantly reduce risk.