April-May 2020 Q&A
Q: Recently we had an employee reference OSHA 29 CFR 1926.960(f) and 1910.269(l)(7), “Conductive articles.” The question is, can an employee work in an energized area while wearing jewelry, and earrings in particular? The rules discuss conductive articles such as watches, bands, rings and chains, but I do not see where it mentions earrings.
A: When it comes to interpretation, it is good to confine a rule to the language used, but sometimes you also have to address the intent. The concern that drove the creation of this rule was whether jewelry, which is conductive, increases electrical contact risk. Those risks are twofold: (1) Does the jewelry make an electrical shock more likely, and (2) does the jewelry increase the damage or level of injury from an electrical contact? This rule does not fit well in the utility industry because its origin is the indoor electrical industry. Electricians rarely employ rubber gloves and were sticking their bare hands in energized panels in close quarters. Still, we can’t ignore the rule, but we can easily address it. As far as electric utilities are concerned, hands in close quarters to uncover bus or wire could cause a flash where jewelry goes to ground. You would get shocked anyway, but the jewelry could cause an arc flash, which increases injury levels with burned skin. That doesn’t really apply where we work unless your uncovered hands are in a meter can. The answer for either 1926 Subpart V or 1910.269 is in the wording of the rule, so look closely: “When an employee performs work within reaching distance of exposed energized parts of equipment, the employer shall ensure that the employee removes or renders nonconductive all exposed conductive articles, such as keychains or watch chains, rings, or wrist watches or bands, unless such articles do not increase the hazards associated with contact with the energized parts.”
First, consider the word “exposed.” If the conductor is covered, the rule would not apply. You could also argue that if you maintained the minimum approach distance, there is no exposure, so again, that would comply with the rule. Next, “increase the hazards” means to identify the hazards. So, which hazards would be associated with earrings and how would they be increased? If you are close enough to distribution that your earrings could come in contact with an energized conductor, you have more problems than just your earrings. I would say earrings are not an issue with regard to this rule.
The only issue I could see is not even addressed by this rule, and that would be the presence of an arc flash. If the arc were close enough, the earrings would heat up quickly and wouldn’t cool off. If the skin were burned, the earrings would increase the burn. So, if the issue was exposure to a flash, a balaclava and most arc flash face shields would render the earrings protected.
Q: Do you know if silicone wedding bands pose any safety issues, including arc flash?
A: There are many compounds of silicone rings available and each will respond to heat differently. The whole idea behind silicone rings was to eliminate the traumatic amputation of fingers known to occur when a ring gets hung up on a solid object and the individual’s body weight pushes against the stuck ring. In the electric industry, OSHA warns against jewelry that could increase the risk of electrocution. Both OSHA and industry consider covering rings by wearing rubber gloves to be a preventive measure.
As to arc flash, in a practical sense, if your hands are exposed to the kind of heat that would melt a silicone ring, you have a pretty significant issue that hardly compares to the discomfort caused by the ring. Silicone is the high-temperature material used in oven seals. Most silicones begin to melt around 500 degrees Fahrenheit, according to information we could find, but that also depends on the compounds in the silicone. Of course, any material will heat when exposed to a heat source, and some materials retain heat well. Silicone tends to transfer heat well and sink (release) heat quickly when pressed against a cooler surface. Unlike gold rings, silicone rings typically are very thin, so heat exchange is rapid, meaning a silicone ring will change temperature fairly quickly on your hand. Metal rings have been known to get hot inside gloves when exposed to a flash. The worker pulls off the gloves to relieve the heat inside only to find his metal rings are still hot.
The bottom line is that silicone rings will heat and cool about as fast as your skin, but they won’t melt as fast as your skin will be damaged by moderate heat exposure. Lastly, if silicone rings are properly covered – as your hands should be when exposed to energized circuits – silicone does not appear to be a safety issue.
Q: Do we need to bond in composite poles for worker EPZ?
A: Yes, but there is some explanation that’s needed. First, most composite pole manufacturers mention that their poles are nonconductive. We say “mention” because they don’t explain or define nonconductive, nor do they include tests for conductivity. Composite poles are not like hot sticks and bucket truck booms that are specifically designed and tested to withstand voltage and current. A nonconductive composite pole for basic insulation level (BIL) is one thing. Nonconductive for isolation and worker safety is a whole lot different.
Technically, there is no such thing as a perfect insulator. That means composites have high BIL, but they do conduct. As such, they are at a different potential than a grounded phase. A worker on the pole steps of a composite pole in contact with a grounded phase, or in a bucket in contact with a grounded phase and composite pole, would be between two different potentials if the composite pole were not bonded to the grounded phase. The good thing is that the composite pole is a poor conductor of current, limiting the amount of current that can flow in a contact. That isolation is similar to a bucket truck. The boom limits the current flow to a low current measured in microamps, well below the threshold of risk for a worker. A worker contacting a phase from an isolated bucket would be shocked by the difference in potential but could not be seriously injured because the boom limits the current across the worker. If you want to know how much risk there is with composite poles, have your boom-test company do a boom test across a composite pole or two. Compare that leakage to the leakage allowed on your aerial booms.
Essentially, if you bond the pole, you eliminate any difference in potential and the shock that can result. When you eliminate electrical shock, you ensure no current can flow across the worker. That is the whole purpose of bonding. If you don’t bond the pole, you can receive a shock, but you cannot be seriously injured if the total current flow is well below the milliamp threshold of risk.
Q: A recent audit of our safe work processes raised a question about the certification of our tool room personnel to perform tests on ground cables. What is the required certification for testing?
A: We have not found any certification requirements or a standard for the certification of a test technician. A brief explanation: When we say “certified,” we mean that the person who is certified has proven through demonstration that they meet the criteria to be certified in a specific task. The criteria for certification typically are created by a group or organization that is recognized to represent a particular industry, or they are criteria established by a government agency. There are no such criteria for technicians who test ground cables. There is the expectation, however, that the employer assures that technicians testing cables are qualified to conduct those tests.
There is a standard for component ratings and assembling and testing grounds. That is where you can find the criteria for conducting tests, and that would be a standard for the technician’s performance. A technician only needs to be able to follow those criteria to conduct the test of the cable. The technician can then certify that the appropriate test was performed and that the cable has passed the required test.
Testing is not the only skill required. In order to be a competent tester of temporary protective grounds, you need to know how to test them as well as how the different clamps, ferrules and cables are rated, how they are constructed and how grounding is used.
Here are the standards we are familiar with:
ASTM F855: Standard Specifications for Temporary Protective Grounds to Be Used on De-energized Electric Power Lines and Equipment
IEEE 1048: IEEE Guide for Protective Grounding of Power Lines
ASTM F2249: Standard Specification for In-Service Test Methods for Temporary Grounding Jumper Assemblies Used on De-Energized Electric Power Lines and Equipment
ASTM B193: Standard Test Method for Resistivity of Electrical Conductor Materials
You can find the standards through a typical online search engine. They cost between $50 and $75. Be sure you get the latest version as the standards are periodically revised.
Q: We have heard that there are recent changes regarding OSHA’s “Cranes and Derricks in Construction” standard and certification of operators, as well as some new restrictions. Have you been able to determine what work does and does not require certification?
A: The only change we are familiar with is a recent decertification of one of the major certifying agencies that was authorized to issue third-party operator licensing. Other than that, the uses of digger derricks and cranes are under the same exceptions as they have been. Only cranes – not digger derricks – are covered under 1926 Subpart CC, “Cranes and Derricks in Construction.” A crane used in any other type of work defined as maintenance is a general industry application and not subject to Subpart CC requirements. Employers using cranes in maintenance are still expected to have competent, qualified operators who follow conventional crane-operating rules for loading, setup, planning, inspections and maintenance.
Digger derricks may be operated by a qualified person in any operation to set poles and equipment used on poles, and to set pads and transformers on pads in either maintenance or construction. This is an exception to the “Cranes and Derricks in Construction” standard; it is clearly defined and very narrow. In substation work, a digger derrick used to set a regulator, breaker, substation steel, foundation reinforcement steel and swing in concrete in civil installations is not exempt from the Subpart CC rules. Digger derricks being used to perform substation-related lifts are considered cranes even though they are digger derricks.
Lastly, an employer using a digger derrick who violates 1926 Subpart V or 1910.269 rules while operating under the “Cranes and Derricks in Construction” exemption will be cited under the Subpart CC rules, including training and certification of the operator.
Do you have a question regarding best practices, work procedures or other utility safety-related topics? If so, please send your inquiries directly firstname.lastname@example.org. Questions submitted are reviewed and answered by the iP editorial advisory board and other subject matter experts.
- Working in Switchgear Cubicles Just Got Safer
- The Hierarchy of Incidents and Learning: Part I
- Human Error and Organizational Resilience
- Take Your Time and Follow the Rules – Or Pay the Price
- Train the Trainer 101: The ABCs of Grounding Mobile Equipment
- Voice of Experience: The Need for Seasoned Industry Trainers
- April-May 2020 Q&A
- Behavioral Profiles: Use DISC to Predict and Adapt