Arc Flash PPE Chart
The proper selection and use of Personal Protective Equipment (PPE) will reduce the risk of arc-flash and other electrical hazards to workers.
OSHA and NFPA 70E regulations stipulate that equipment should be de-energized before any work is done. But there are exceptions to the rule:
- Performing diagnostic tests such as checking for voltage and current;
- If deenergizing the equipment would create a greater hazard, or;
- If the system voltage is below 50 volts.
In Canada, CSA Z462 is the standard that is substituted for NFPA 70E.
PPE will not eliminate injury, but it will substantially reduce the level of damage done to the human body.
NFPA 70E provides two methods for PPE selection. The first presents common work tasks in a table format along with the respective Hazard/Risk Category for each task. The PPE is then selected based on the Hazard/Risk Category.
The second method requires a Flash Hazard Analysis, providing a more detailed look at the individual task and electrical system. PPE is then selected based on the incident energy level calculated during the Flash Hazard Analysis.
The requirements for PPE are defined in the following categories*:
| Category 0 | Less Than 2 cal / cm2 |
Non-melting flammable materials, glasses/face shield, leather gloves over rubber
Fire Resistant (FR) shirt and FR pants
FR shirt, FR pants, cotton underwear
2 layers of FR clothing, cotton underwear
FR shirt, FR pants, multi-layer flash suit, cotton underwear
*Categories 1-4 should include face shield and foot protection
- Some of the components and calculations used to determine this protective safety clothing chart include:
- Incident Energy – measurement of thermal energy at a specified distance from the arc (normally 18 inches). Incident Energy is typically measured in cal/cm2.
- Arc Thermal Performance Exposure Value (ATPV) – the incident energy level (in cal/cm2) that would cause the onset of a second-degree burn as defined by ASTM P S58 Standard.
- V-rated – tools and gloves rated and tested for the line-to-line voltage at the area where the work is to be performed.
- Flame Resistant or Flame Retardant (FR) – a term referring to fabric and its ability to limit the severity of burning.
- Breakopen Threshold Energy (EBT) – the highest incident energy level which did not cause flame resistant (FR) fabric breakopen and does not exceed second-degree burn criteria.
Read More Here: Arc Flash and Electrical Safety
- Read More Here: Electrical Safety Training
- Read More Here: Electricity
For more information, see:
Electrical Safety OSHA
Electrical Safety Workplace
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