Classification of Arc Flash Hazards
November 4, 2016 | Stephen Byers
What we have learned in the past decade while performing flash hazard studies is that there is no ‘One Size Fits All’ method when it comes to classifying the hazard levels at equipment and its subsequent labeling. While NFPA 70E provides general guidelines on what minimum information should be included on a label (see 130.6(D)), there is still a considerable amount of flexibility on how equipment may be labeled and categorized.
The more traditional approach, which many clients still prefer, is to label equipment based on six different hazard levels; Categories 0-4 plus ‘Dangerous.’ While this approach allows for smaller groupings of equipment with the same incident energy ratings, it was not particularly effective in helping select the proper PPE when performing energized electrical work. This is due to the fact that most employers that require their employees to work ‘hot’ don’t provide 5 different sets of PPE to accommodate the labeling. In fact, it seems to be most common to have both a ‘Category 4’ bag and a ‘Category 2’ bag available; essentially ignoring the Categories 1 and 3.
The more streamlined approach is to simply label equipment as Categories 0, 2 and 4 and then provide the PPE necessary for those hazard levels. While using all of the same information and calculations for specific busses, it cleans up the PPE tables and employees are left wondering where the Category 1 and 3 PPE bags are located.
While the ‘Category’ ratings are effective and useful, we are seeing more and more clients who are removing the ‘Category’ or ‘Level’ wording from labels and simply providing the information necessary for a trained and qualified employee to select the appropriate PPE and perform their work safely. This move, combined with the application of a thorough risk assessment for each and every task, will prove, we believe, to be a far more effective application to keep your employees happy and injury-free.