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Making Sense of Electrical PPE
OSHA has increased compliance activities related to electrical safety regulations and standards in the past few years. This began with the heightened interest in arc flash hazards starting with the 2000 NFPA 70E standards and became more active after the 2004 edition was published. On Feb. 14, 2007, OSHA updated a portion of Subpart S (1910.302-308), and soon after a mandate for Compliance Officers to attend training on electrical regulations and associated NFPA 70E standards was issued.
In 2009, the NFPA published a more polished and clear 70E standard. OSHA is now poised to cite any company that opts not to comply with electrical-related regulations and has even stopped or delayed VPP renewals. A major part of their effort continues to focus on employee protection, first by eliminating the hazard through proper lockout/tagout and other administrative controls or barriers, and second by the use of personal protective equipment (PPE). There is a wide interpretation on the use of PPE, along with the definition of a "qualified worker." PPE as required to protect qualified workers from electrical hazards is not difficult to implement.
Many companies hire licensed electricians to fill their maintenance needs, making the assumption that they are qualified. This may be true, but more often than not, they are not safety qualified. Another misconception involves a person working on a manufacturing line doing regular electrical testing to ensure the equipment manufactured is functioning properly. Some feel this person would not be considered qualified, so rules for qualified workers related to the level of training are not required.
In both cases, there are minimum requirements set forth by OSHA. A qualified worker was defined by OSHA in 2007 as "One who has received training in and has demonstrated skills and knowledge in the construction and operation of electric equipment and installations and the hazards involved." The term that is critical in the development of an effective training program and which requires regular employee observation is the word "demonstrated." OSHA personnel will look for documentation to determine whether your qualified employees have demonstrated their skills and knowledge, especially if they identified a deficiency in work practices or procedures during their observation.
Assessing the Hazards
There are two levels of assessment to consider, including a general hazard assessment for PPE requirements as outlined in 29 CFR 1910 Subpart I, Section .132 and a pre-work personal hazard assessment or "job briefing." Qualified workers must also have the skills and techniques necessary to distinguish exposed live parts from other parts of electric equipment, determine the nominal voltage of exposed live parts, know the clearance distances for the various nominal voltages (NFPA Restricted Approach Boundary) and also understand several specific special precautions related to capacitors, CTs, lighting requirements, gradient potential (medium voltage or higher), PPE requirements and emergency response related to electrical contacts.
These issues are part of a qualified worker's daily work and require that an assessment is done prior to beginning work, whether he is an electrician, a facilities maintenance worker, or a production line worker performing electrical tests. The level of this "job briefing" depends on whether the work is routine or non-routine and the complexity or level of risk of injury to the employee.
With this requirement, each qualified worker should determine the shock hazard by identifying the exposure to electrical parts, the nominal voltage of those parts, and shock PPE required for adequate protection within the determined minimum approach (or restricted approach -- NFPA 70E) boundary. Protection from arc flash/blast hazards is determined by examining arc flash labels or by going by the company-written electrical safety program criteria, where the arc flash hazard level has been determined by the employer.
A personal protective equipment assessment shall be performed by all employers. Electrical PPE requirements are broad and do not contain specific PPE particularly related to arc flash hazards. OSHA will cite companies based on non-compliance with 29 CFR 1910.132 or go to Subpart S, 1910.335(a)(1) or 1910.269 for work related to generation, transmission, or distribution of electricity (usually associated with medium and high voltage). To cite specific electrical PPE requirements, OSHA has cited NFPA70E under the General Duty Clause in excess of 30 times.
During the job briefing hazard assessment, the nominal voltage is identified. This will provide information needed to determine the shock prevention measures. First, try to completely de-energize the enclosure before opening doors or removing covers. If this is infeasible, then some level of PPE will be required before removing covers, depending on the voltage.
Most common voltages in the United States are 120/240 volts single phase and 120/208 and 277/480 volts 3 phase, and in Canada the 575 volts is the most common 3 phase power system. It's important to know that any voltage can kill. There have been fatalities on 48 volt controls.
To protect against shock hazards, some basic equipment should be available and used. Remember that the goal is to increase the resistance in the body where a contact could cause electricity to flow. From head to toe, protective equipment includes electrical-related hard hat Class E or G, rubber insulated gloves, and EH-rated boots. For 480 and 575 volt work, the minimum approach distance is 12 inches from uninsulated body parts, so rubber gloves are required to be on before opening the door or removing a cover to exposed parts.
This is required even if de-energized because it must be tested to be sure it is de-energized. Class 0, 14-inch rubber gloves with leather protectors are the best option because class 00 are rated for 500 volts, and often 480 volt systems exceed this level. The length is important because 12-inch rubber gloves have a rolled cuff, so the lower arm will be within the minimum approach boundary when testing using a meter.
Rubber gloves are required to be air tested before each day's use and lab tested at least every six months. To make the testing easier, have one person in charge of all rubber glove testing. Ask your lab to stock your second pair of gloves, then test and ship them in five months so that employees need only to change them when received and ship them back. It may help to have two different colors of gloves. As an example, the yellow gloves are the summer gloves and the red gloves are the winter gloves. This will help to ensure the test has been done within the defined timeframe. Thin cotton liners are nice to soak up sweat or if gloves are shared (i.e., test or assembly areas with shift workers). Leather protectors should be used to protect the rubber gloves (shall be for Classes 1-4). Medium voltage requires higher rated gloves in addition to the use of hot sticks and grounding equipment. Other tools that every electrical worker should have includes insulated hand tools, insulated fuse pullers, portable GFCI cord or pigtail for cord and plug tools, rubber barrier material, and UL listed CAT III and/or CAT IV test meter.
Arc Flash Protection
Arc flash and blast hazards present more of a challenge. As discussed above, a hazard assessment is required by all employers to determine PPE. The level of hazard related to the arc flash depends a few variables: the available bolted fault current supplied from the source, the clearing time (time at which a breaker opens or fuse blows), and the impedance between the point of the flash and the source. How these are determined can vary.
Some companies contact the utility to determine fault current, and then use the NFPA 70E tables if within the fault current specified in the notes. This may meet minimum OSHA requirements for PPE assessment but is not the best way to decide on protection levels for your employees. Often it's more than needed; occasionally, it’s not enough. The better approach is to calculate the incident energy levels in calories per square centimeters (cal/cm²) and determine boundaries at which the incident energy level drops to 1.2 cal/cm². This is called the flash protection boundary. Above this level will cause a second-degree burn to bare skin. The study will also determine exactly what the cal/cm² is at the working distance (typically 18 inches for 480 or 575 volt work).
Now we actually know precisely what level to protect both qualified employees and non-qualified employees. We will require our qualified employees to wear arc-rated clothing that has a rating in cal/cm² that is greater or equal to the calculated level at the working distance. This is in addition to the shock protection required in the previous paragraph. The simplest way to comply with arc-rated clothing requirements is to have qualified workers wear 8 cal/cm² for day-to-day work (or coveralls of the same rating over cotton clothing) and wear an arc shield for any work where the incident energy was determined to be less than 8 cal/cm². Consider requiring an arc-rated balaclava hood whenever the shield is used for added face and neck protection. For work with higher identified hazard levels, a 40 cal/cm² suit should be worn. Anything rated greater needs to be de-energized or engineer out the hazard via remote working procedures.
Other PPE related to the arc flash or blast to consider wearing is plastic-rimmed safety glasses and ear plugs. The qualified worker should also install DANGER tape or a similar barricade at the flash protection boundary to protect non-qualified employees from arc flash hazards.
So that's it! Have a written program to outline hazards and procedures required to effectively eliminate or engineer out all possible electrical hazards. If that is not feasible, then protecting employees with proper PPE is critical. This includes rubber gloves, EH-rated boots and hard hat with arc shield, plastic-rimmed glasses, ear plugs, and arc-rated clothing to the level of the hazard.
It doesn't have to be a stressful process. Remember that ignorance of these regulations will not work as a defense of an OSHA citation or when answering questions in a tort case following an electrocution.
This article originally appeared in the October 2011 issue of Occupational Health & Safety.