Insulating rubber gloves are designed specifically for constant contact with, and protection from, energized conductors and equipment. Wearing the wrong rubber insulating gloves when dealing with this hazard, however, leaves your workers at risk of electrical injury or, possibly, death.
A Critical Safety Issue
According to Electrical Safety Foundation International (ESFI), there were 134 electrical fatalities in 2015. Of those, 81 were construction workers, but the danger is present in various industries. Electricians, municipal utilities technicians, and maintenance workers replacing an office's light fixtures all need to protect against electrical injury.
It's worth pointing out that it isn't just workers in traditionally electrical fields who are at risk. According to OHS online, half of the people who are killed from accidental contact with energized conductors work in related fields, such as painters and repair personnel.
Since even those who don't come into constant contact with electrical equipment can accidentally be exposed to an electrical charge, giving employees a clear understanding of electrical safety should be part of safety programs across many fields of work (learn about Five Leading Electrical Hazards and How to Avoid Them).
Voltage Classes for Rubber Insulating Gloves
While training is essential, workers will not be entirely safe unless they're given the right kind of safety glove. ASTM D120 defines six AC voltage classes. Each requires a proof test at a significant voltage much greater than the voltage for which it is approved for use:
- Class 00 (low voltage) – Proof-tested at 2,500 volts for max. use of 500 volts
- Class 0 (low voltage) – Proof-tested at 5,000 volts for max. use of 1,000 volts
- Class 1 (high voltage) – Proof-tested at 10,000 volts for max. use of 7,500 volts
- Class 2 (high voltage) – Proof-tested at 20,000 volts for max. use of 17,000 volts
- Class 3 (high voltage) – Proof-tested at 30,000 volts for max. use of 26,500 volts
- Class 4 (high voltage) – Proof-tested at 40,000 volts for max. use of 36,000 volts
ASTM D120 also specifies similar proof test and max use levels for DC voltage.
In cases where different types of gloves are needed on the same work site, workers need to be able to quickly select the right pair for the task. Simply grabbing the nearest ones available is not safe. Gloves should be clearly marked to indicate the level of protection they offer. Look for gloves and sleeves that have a color-coded label indicating the voltage class. Adding signage near the site where PPE is stored and distributed is a good way to remind workers to use the right gear for the job.
Rubber insulating gloves must be worn with leather protector cover gloves. But not just any leather work glove can be used – specific leather protectors are made in accordance with ASTM F696. Leather protectors are designed to protect the rubber from cuts, abrasions, and punctures. Think of it this way: the rubber protects the wearer from the voltage, and the leather protects the rubber from other physical hazards.
Know Your ASTM Specs
Insulating gloves should be tested to make sure they meet the expected standards. The American Society for Testing and Materials (ASTM) works across borders, disciplines, and industries to harness the expertise of more than 30,000 members to improve performance in manufacturing and materials, products and processes, and systems and services. This exacting organization's Manufacturing and Acceptance standards mandate the testing of rubber insulating products by the manufacturer or supplier prior to its delivery to the end user.
But those users also have the option of testing the products themselves. Before issuing the equipment to workers, employers should test the gloves according to the manufacturer's specifications and document the results in company records. Once rubber insulating equipment is placed in service, it should be re-tested at intervals specified by ASTM:
- Rubber Insulating Gloves: 6 months (9 months under certain conditions)
- Rubber Insulating Sleeves: 12 months
- Rubber Insulating Blankets: 12 months
- Line Hose and Covers: When field inspection or company policy warrant
Of course, these intervals are permitted maximums and the equipment can be inspected more frequently, especially if it is used daily or in applications that may put additional stress on it. Supervisors in industries specifically related to power use, such as utilities, should specify shorter intervals for inspecting and testing.
Field testing PPE is crucial. The best approach for care, inspection, and storage are often different in the field than they are within a facility. Constant exposure to direct sunlight or moisture, for instance, may compromise the rubber gloves' insulating qualities. To keep them in service as long as possible, make sure the gloves are stored and dry when not in use.
Workers in the field should examine their gloves for punctures and other defects. Workers can also roll the glove up to trap air inside, and then hold the gloves against the skin to feel whether any air is escaping from a puncture that was missed by the visual check. Employers can also provide a portable mechanical inflator to help workers inspect their insulating equipment in the field. The glove is attached to the inflator and pumped up for a few seconds to view any damage that may be present.
Some manufacturers make the inspection process easier by using two different colored layers in their gloves. If the outer layer is damaged, the contrasting color of the inner layer gives a clear visual indication of that damage.
Workers should also give their leather protectors a daily check. Dirt and grime can hide damage to it, and embedded wires or metal shavings could puncture or damage the gloves.
Best practice for storing gloves is to remove the leather protector from the rubber after the work is completed. Store the rubber and the leather in a dedicated storage bag.
It's no secret that electricity is dangerous. Make sure that workers who come into contact with energized equipment are given the right level of protection and that their insulated gear is properly cared for.