Despite strict workplace safety regulations and the prevalence of rubber gloves and sleeves, workers still suffer a significant number of injuries from electric shocks and arc flashes every day. According to CapSchell Inc., a workplace safety research and consulting firm, as many as ten U.S. workers are injured by arc flash explosions every day.
These disturbing figures are backed up by estimates from OSHA, which suggest that arc flashes account for well over 75% of the electrical accidents and fatalities that involve qualified persons.
Faced with these sobering statistics, regulators, employers, and employees have begun to look at additional ways to protect workers from arc flashes and arc blasts.
Arc Flash Causes
According to the National Fire Protection Association (NFPA), arc flashes result from electrical current traveling through the air because insulation can no longer contain the applied voltage, resulting in highly ionized air. This can be caused by a number of things. It may, for example, result from faulty equipment that has deteriorated or corroded due to usage. Equipment that is underrated for the short circuit current might also be the culprit.
No matter what the source, the result is extremely high – and potentially deadly – temperatures, which can reach up to 35,000°F.
One safety measure is to "de-energize" equipment before workers start using it. For a number of reasons, however, this is not always feasible. In some situations, moreover, de-energizing equipment can actually increase the risk to workers. Since this is far from a perfect solution, there has been increased attention on using appropriate PPE to reduce the risks associated with arc flashes.
Employers should regularly inspect all the equipment in their facility to identify potential arc flash hazards. An arc flash hazard analysis can help you make a more informed decision about the kind of PPE your employees will need. It will allow you to identify the amount of energy required for an arc flash to second degree burns and help you delineate the danger areas around equipment that poses arc flash risks.
Rubber Safety Gloves: An Essential Tool
Workers' hands tend to be at the highest risk during arc flash explosions. Many workers wear arc-rated work gloves that will protect them from high temperatures. However, they often don't provide any protection for the electric shocks that can result from arc flashes. Anyone working with electrically energized equipment, then, should be using rubber safety gloves.
But not all safety gloves are created equal. Different gloves provide different levels of voltage protection. To simplify the purchasing process, rubber safety gloves are classed according to the maximum voltage they can protect against. Every voltage protection class comes with a color-coded label:
- Class 00 – Beige Label: Max. use voltage 500 volts AC; proof tested to 2,500 volts AC
- Class 0 – Red Label: Max. use voltage 1,000 volts AC; proof tested to 5,000 volts AC
- Class 1 – White Label: Max. use voltage 7,500 volts AC; proof tested to 10,000 volts AC
- Class 2 – Yellow Label: Max. use voltage 17,000 volts AC; proof tested to 20,000 volts AC
- Class 3 – Green Label: Max. use voltage of 26,500 volts AC; proof tested to 30,000 volts AC
- Class 4 – Orange Label: Max. use voltage 36,000 volts AC; proof tested to 40,000 volts AC
Regular Inspections: A Key to Safety
Purchasing and regularly wearing PPE is only part of the process for keeping workers safe in the event of an arc flash. Safety gloves also require regular inspections and testing to ensure that they are still capable of appropriately protecting workers. Various regulatory agencies, such as OSHA, ASTM, and the NFPA, have established testing protocols.
Testing at accredited laboratories is recommended. But, between these tests, workers should regularly inspect their own equipment – looking for potential physical, ozone, or chemical damage.
The best way to inspect rubber gloves is to inflate the gloves to approximately 1.25 to 1.5 times their normal size. When the gloves are inflated, it is then possible to listen to see if any air is escaping. This telltale sign indicates a possible hole in the glove which would compromise its safety. After checking the gloves from the one side, turn them inside out and again inflate them again.
Workers should also be shown how to visually inspect their gloves. These visual checks can spot more obvious damage like punctures, snags, and cuts.
And Don’t Forget to Test
Inspections are essential, but so is testing. While testing can be done at the work site, many companies don't have the appropriate testing equipment. Rather than purchasing their own, they can send the rubber gloves out to accredited independent testing sites, such as those accredited by NAIL4PET.
These tests should be performed every six months for most industries. Companies in the telecommunication sector face a lower risk of arc flashes and other related events. They can, therefore, extend the testing interval to every nine months.
Storing Your Gloves
Storing your PPE should be treated as an important part of its maintenance, not as an afterthought. Proper storage ensures maximum protection while also extending the functional life of the equipment.
Store your gloves in an approved storage bag, preferably one made of canvas. The gloves should be placed with the fingers pointing up and be right side out. Folding the gloves or storing them inside out puts a strain on the rubber that may lead to cracks or punctures. The bags should be placed in a cool and dry location away from direct sunlight.
Arc flashes are a dangerous and deadly phenomenon. But with the right equipment and good maintenance, workers can make sure their hands are safely protected (for more on electrical safety, see Five Leading Electrical Hazards and How to Avoid Them).