OSHA rules and NFPA standards make the use of rubber insulating products mandatory when even the smallest probability of contact with 50 volts AC or higher exists. These rules affect nearly all industrial workplaces, as every single facility (including utility contractors and general contractors) has a need for electrical safety and arc flash protection, and failure to comply can result in heavy fines, serious injury and even death. Moreover, OSHA and ASTM standards also require regular inspection and testing of in-service electrical protective equipment in order to maintain compliance and ensure the products’ safety and integrity when exposed to a wide range of voltages. Fortunately, there are safety measures and solutions that you can easily employ to help prevent injuries, citations and penalties including visual inspection and electrical testing.
Rubber Goods Visual Inspection
Rubber insulating products must be inspected before each use. Common problems to look for include the following:
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Cracking and Cutting – Prolonged folding or compressing can cause this type of rubber damage.
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UV Checking – Storing in areas exposed to prolonged sunlight causes UV checking.
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Chemical Attack – Oils and petroleum compounds can cause swelling of the rubber.
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Avoid Folding – The strain on rubber at a folded point is equal to stretching the rubber to twice its length.
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Snags – Wood, metal splinters and other sharp objects can snag or tear rubber.
- Physical Damage – Rope burns, deep cuts and puncture hazards are cause for rejection.
Insulating Rubber Glove and Sleeve Care
Visually inspecting rubber gloves and sleeves identifies physical, chemical or ozone damage. Direct light is recommended because it enhances the ability to see surface imperfections on the rubber. Inflating the gloves with air or otherwise stretching the surface helps identify age and ozone damage as well as other physical damage such as cuts, snags, abrasions or tears.
Expand gloves no more than 1.5 times their normal size for Type I rubber and 1.25 times normal for Type II rubber. Listen for escaping air to detect holes. If a portable inflator is not available, use a rubber glove inspection tool or roll the glove cuff tightly to trap air inside. Then, apply pressure to areas of the glove to inspect for escaping air. Repeat the procedure again with the rubber gloves turned inside out.
When inspecting rubber sleeves, make sure to examine them along the edge as they are rolled. Rolling will stretch the sleeve along the edge, making cuts, tears and ozone cutting more visible. Repeat this process again with the rubber sleeve turned inside out.
Insulating Rubber Blanket Care
Roll rubber insulating blankets to properly inspect them in order to locate scratches, tears, abrasions, snags, corona cutting or age cracking. Make sure to roll the blankets two times on each side, with the second roll at a right angle to the first. Immediately remove blankets from service that show any signs of damage.
Insulating Rubber Line Hose Care
Make certain to thoroughly inspect rubber insulating line hose, hoods and covers inside and out for cuts, scratches, corona cutting, holes, tears and punctures, aging, rope or wire burns and texture changes such as swelling, softening, hardening, becoming sticky or inelastic.
Electrical Testing
After the visual inspection is completed, electrically test the rubber goods at their rated test voltage using specialized equipment designed to gradually increase the voltage to the desired test level. The dielectric test is two-fold: pass/fail on the ability to withstand the rated test voltage and, for gloves, quantitative on the ability to prevent electric current from passing through the rubber goods above the maximum contained in the specifications. Products passing the inspection and test procedures can then be returned to service.
Testing is a critical component to electrical safety in that not only does it help maintain compliance, but it also helps to increase savings. ASTM F478 (insulating line hose and covers), ASTM F479 (insulating blankets) and ASTM F496 (insulating gloves and sleeves) specifications apply to the in-service care of rubber insulating products. Moreover, rubber insulating products are costly, and many times these costs are unnecessarily increased by purchasing replacements for products that could have remained in service with the proper testing and recertification.
If you do not have the equipment required to perform these electrical tests, there are independent testing facilities that can perform the acceptance and in-service testing on behalf of end users.
At a minimum, ASTM standards require that the inspection and testing process include the following steps:
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Check-In
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Removing previous testing marking
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Washing using cleaning agents that will not degrade the insulating properties
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Visual inspection of all services (inside and out)
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Electrical test
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Final inspection
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Recordkeeping
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Marking
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Packing in appropriate containers (“appropriate containers” means boxes, or similar sturdy packaging materials to prevent folding, creasing or similar loose storage that can cause stress on the rubber) for storage or shipment
When selecting a test lab for use, make sure that it is a NAIL-accredited test lab. NAIL stands for National Association of Independent Laboratories for Protective Equipment Testing (www.nail4pet.org). It incorporates the only Laboratory Accreditation for the electrical equipment test labs program in North America. NAIL4PET helps develop uniformity in testing and works in close association with the American Society of Testing Materials (ASTM International).
The interval between the date of issue and electrical testing should be based on work practices and test experience. For gloves, the interval shall not exceed six months except for industries such as telecommunications that utilize insulating gloves as precautionary protection, in which case the maximum interval may be increased to nine months. For sleeves and blankets, the interval shall not exceed 12 months. For line hose and covers, no minimal maximum interval is specified; electrical testing shall be performed if the periodic cleaning and visual inspection identifies conditions that might adversely affect performance and safety. Keep in mind that all electrical protective rubber insulating products are tested by the manufacturer prior to the first shipment. End users (or an end users’ designee) may perform acceptance testing within the first two months after receipt. However, do not place rubber insulating products into service unless they have been tested electrically within the previous 12 months.
With so many workers using rubber insulating equipment and so many testing interval variables to consider, it is easy to see how compliance can fall through the cracks. Consider partnering with an electrical test lab that can test your rubber goods AND manage the rubber goods change-out process for you. Keeping these services bundled together under one roof will minimize out-of-service time and save money by delivering a start-to-finish solution that includes cleaning, visual inspection, electrical testing, markings according to your safety protocols and shipment to your warehouse or jobsite so that you can focus on other work priorities while staying safe, productive and compliant!
Richard A. Rivkin is President and Chief Executive Officer of Saf-T-Gard International, Inc., a privately-held family-owned and operated global supplier of industrial safety products based in Northbrook, Illinois. Founded in 1936 as Latex Glove Company, Saf-T-Gard carries on the tradition that was started more than 79 years ago: bringing customers the products, training and service they need to keep employees safe in the workplace. Saf‑T‑Gard actively operates the Voltgard Test Lab, one of the largest, independent, NAIL4PET-accredited test labs for rubber insulating products in the United States. To learn more, please visit www.saftgard.com or call 1-800-548-GARD (4273).