After 15 years of arc flash testing, research, and replication with arc flash, some critical lessons have emerged in Personal Protective Equipment (PPE) programs:
1. Should PPE be used?
Whether it’s a lack of training on its importance, or a policy that says, “Wear it when needed,” or you didn’t choose the right garment for the job. PPE is no good if it is not used. Most accidents occur when the worker believes that he does not need protection. If the employer buys the least expensive garments, he will have poor compliance with his policy. Another reason PPE is not used is that the company believes more is better and provides heavy and uncomfortable PPE. If used all the time, less may be better. The biggest difference in arc flash clothing is the difference between non-FR and FR. Worrying about the difference between a 100 cal/cm² suit and a 40 cal/cm² suit is missing the point. Many companies offer 100 cal/cm² suits, which are not used. It is better to have a worker in an 8 cal/cm² shirt and arc resistant jean than 100% cotton because arc resistant clothing will not ignite.
The cheapest suits tend to be heavy, but if the workers use them for a short time, they are a good option. If workers are working in arc flash hoods more than 20 minutes per day, consider a light suit, which is at least 40 cal/cm². Some of the 40 cal/cm² suits are half the weight of others. Adding ventilation to a hood can add $200 to the cost of the hood, but can make a big difference in worker comfort. Field test options to see real-world performance. Considering cost and convenience increases compliance.
2. Flame resistant on the label means nothing.
EN Acrylic, nylon and polyester are not really flame resistant for practical purposes. These materials should use another name because “fire resistant” by definition gives the user the wrong impression. They may be fine for a worker who has little or no exposure to flames, but are dangerous in arc flash and flash fire conditions where these products melt on the skin. The products you choose must meet the correct standards.
Here are the standards to specify:
– Clothing — ASTM F1506 or IEC 61482
– Rainwear — ASTM F1891
– Hoods and Face Shields — ASTM F2178
– Fall protection exposed to arc flash — ASTM F887
– Gloves — ASTM D120
– Flash Fire Clothing — NFPA 2112, CGSB 155.20
3. Wear FR rainwear instead of arc-rated rainwear.
Make sure you have the proper waterproof clothing. Only rainwear that meets ASTM F1891, F2733, or NFPA 2112 standards will not melt in arc or flash fire conditions. Arc-rated rainwear is typically made from DuPont’s Nomex® or Kevlar® or a blend. Nylon or polyester, even if labeled “FR,” are not acceptable in rainwear exposed to arc flash or flash fire.
4. Wearing non-FR winter clothing over FR and thinking you’re protected.
An FR shirt under a flammable jacket will not protect. Winter clothing that does not meet ASTM F1506 is dangerous in an arc flash. In two accidents I have investigated, a non-FR winter jacket burned workers under FR clothing over 50% of their body. Many winter jackets are now available that keep workers warm and protected. Try Westex’s Indura(TM) ModaQuilt(TM) or the new 3M FR Thinsulate or many other non-melt options that are F1506 tested.
5. Do not train in underwear.
To comply with the NFPA 70E standard, workers must wear non-melt natural fiber undergarments or arc-rated undergarments. Flame resistant bras and other undergarments are available. Avoid any absorbent material that can melt. These materials should not be used as undergarments in arc flash or flash fire exposures. Solid cotton, wool, and silk are good choices for winter underwear or arc-rated t-shirts made from materials such as Indura UltraSoft® Knits, Springfield’s FireWear®, ITI’s EMC(TM), SSM’s ProC FR(TM) , DRIFIRE, FR Wickers wool or various Nomex® Knits are acceptable.
Simplifying an arc flash PPE program by wearing 8 cal/cm² protection every day and adding an arc flash rain suit, or an additional coverall or hooded arc flash light suit makes it easier to live and work with a complete program.
