Arc flash clothing has been around for years now.  Early personal protective equipment was typically made of one or two fabric layers.  Heavier clothing was used when the need for greater protection existed.  Today’s arc flash clothing is made with a multi-layered construction, making the clothes lighter and easier to wear.  Wearing layers of clothing increases the ability of the PPE to dissipate the heat from arc flash.   It is important to view PPE as a system, because of the need to use individual articles of clothing and equipment together to improve performance against arc flash hazards.

A general guideline is that for every layer of clothing worn under arc-rated clothing, heat will drop by fifty percent per layer.  Keep in mind this is for bodily areas that are covered.  The air between the layers of clothing will increase the ability of the arc-clothing to dissipate heat.  Now, if a person wears an underlayer made of meltable fabrics such as spandex, the chance greatly increases of residual burns from arc flash.  Spandax, being a synthetic fabric can melt even at 180 degrees F. temperatures.    Enough heat can transfer through arc-rated clothing to melt underlayers.  For this reason, cotton underlayers are recommended in most cases although fire resistant underlayers are ideal.

Understanding the importance of a layered system of protective clothing and additional PPE is part of being a qualified electrical worker as well as providing protection in the case of electrical incident.  Layering clothing provides extended performance of arc-rated clothing and offers a method to minimize burns to heat transfer during an arc flash.

Tags: arc flash clothes, arc flash hazards, burns, layers, PPE, protective clothing

This entry was posted on Tuesday, September 16th, 2008 at 12:08 am and is filed under PPE. You can follow any responses to this entry through the RSS 2.0 feed. You can leave a response, or trackback from your own site.