Identifying PPE Mistakes in Electric Arc Flash Programs
After a decade of electric arc testing, incident investigations and incident replications using electric arcs, a few lessons have emerged as critical in assessing a Personal Protection Equipment (PPE) program:
1. PPE ISN'T WORN
Whether it's because of a lack of training about its importance, a policy that says, "Wear it when you need it," or because the right suit is not being provided for the job, PPE does no good if it isn't being used. Most accidents happen when workers think they don't need the protection. Are you simply buying the least expensive suit? While some companies believe that more is better and provide heavy, uncomfortable PPE, less can actually be better. The largest difference in FR clothing is the difference between non-FR and FR. To worry about the difference between a 100 cal/cm2 suit and a 40 cal/cm2 suit is to miss the point. Many companies will provide 100 cal/cm2 suits, which are not worn. It's better to have a worker in a 4 cal/cm2 shirt and an FR jean than in cotton because they didn't want to wear the heavier suit all day.
Less expensive suits are heavier in weight than other suits but are a great value if workers are wearing them for a short time, such as for routine switching for a few minutes. If your workers are working in flash suits more than 10 to 15 minutes per day consider a lightweight, highly protective suit, which meets 40 to 65 cal/cm2 but weighs in at less than half the common suits on the market. Adding venting technologies may add only $100 to the cost of the suit, but it can also make a huge difference in worker comfort. Other options include PAPR-type devices, which can also filter air if your exposure requires it. Field trial your choices to see how they perform. Considering cost and comfort will increase worker compliance.
2. FR IS NOT FR ALL THE TIME
FR acrylics, FR nylons and FR polyesters are not really FR for most practical purposes. These materials should have another name because "flame resistant" by definition gives the end user the wrong impression. They may be fine for a worker who has little or no flame exposure, but they are worse than useless in electric arc situations where supposed FR products can melt to workers. FR products should be avoided unless they meet truly arc resistant ASTM standards. Other flame resistant standards are useless in electric arc. Here are the standards to specify:
• Clothing — ASTM F1506
• Rainwear — ASTM F1891
• Hoods and Face Shields — ASTM F2178
• Fall Protection Exposed to Electric Arc — ASTM F887
• Gloves — ASTM D120
• Flash Fire Clothing — NFPA 2112, CGSB 155.20.
3. USING FR RAINWEAR RATHER THAN ARC THERMAL RESISTANT RAINWEAR
Make sure you have the right raingear, which means only rainwear that complies with ASTM F1891 or NFPA 2112. Arc Thermal Resistant rainwear is usually built on DuPont's Nomex(r) or Kevlar(r) or a blend of both. Nylon or polyester, even if labeled "FR," are usually not acceptable in rainwear when exposed to electric arc.
4. USING NON-FR JACKETS AND WINTER WEAR OVER FR AND THINKING IT IS OK
An FR shirt under a heavy flammable jacket will not provide protection. Winter wear that does not meet ASTM F1506 is inadequate for electric arc exposure. In two accidents I have helped to investigate, a heavy non-FR winter jacket burned workers under their FR clothing to 60% body burn or greater, life threatening in most cases. Westex's InduraT ModaQuiltT has been used successfully for years and the new 3M FR Thinsulate is just coming on the market in FR winter wear.
5. NO TRAINING ON UNDERGARMENTS
In order the meet the NFPA 70E standard, workers are required to wear non-melting natural fiber clothing at a minimum or FR underwear. Flame resistant bras and other undergarments are now commercially available. Avoid new wickable melting T-shirts and wickable, meltable underwear. These materials should not be part of undergarments in arc or flame situations. Plain cotton, FR wool and silk are all good options for winter undergarments or FR T-shirts made from Indura UltraSoft(r) Knits, Springfield's FireWear(r), ITI's EMCT, SSM's ProC FRT or various Nomex(r) Knits.
Simplifying your arc flash PPE program by using daily wear with 4 to 8 cal/cm2 and adding an arc flash rain suit, an additional coverall or a lightweight flash suit with a flash suit hood makes a well-rounded program easier to live with and work in. ip